rwrap: fix resolv wrapper with ipv6 addresses and old glibc versions
[resolv_wrapper.git] / src / resolv_wrapper.c
index 8d0d67e4b1eb54c484ceb192d83efa792ef09d8a..20ba2d1a899536977daaa20ac6bd9d5dacbf7272 100644 (file)
@@ -1,6 +1,6 @@
 /*
- * Copyright (c) 2014      Andreas Schneider <asn@samba.org>
- * Copyright (c) 2014      Jakub Hrozek <jakub.hrozek@gmail.com>
+ * Copyright (c) 2014-2018 Andreas Schneider <asn@samba.org>
+ * Copyright (c) 2014-2016 Jakub Hrozek <jakub.hrozek@posteo.se>
  *
  * All rights reserved.
  *
 
 #include <errno.h>
 #include <arpa/inet.h>
+#ifdef HAVE_ARPA_NAMESER_H
+#include <arpa/nameser.h>
+#endif /* HAVE_ARPA_NAMESER_H */
 #include <netinet/in.h>
+#include <sys/socket.h>
 #include <sys/types.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #define RWRAP_DEFAULT_FAKE_TTL 600
 #endif  /* RWRAP_DEFAULT_FAKE_TTL */
 
+#ifndef HAVE_NS_NAME_COMPRESS
+#define ns_name_compress dn_comp
+#endif
+
+#define ns_t_uri 256
+
 enum rwrap_dbglvl_e {
        RWRAP_LOG_ERROR = 0,
        RWRAP_LOG_WARN,
+       RWRAP_LOG_NOTICE,
        RWRAP_LOG_DEBUG,
        RWRAP_LOG_TRACE
 };
 
-#ifdef NDEBUG
-# define RWRAP_LOG(...)
-#else /* NDEBUG */
+#ifndef HAVE_GETPROGNAME
+static const char *getprogname(void)
+{
+#if defined(HAVE_PROGRAM_INVOCATION_SHORT_NAME)
+       return program_invocation_short_name;
+#elif defined(HAVE_GETEXECNAME)
+       return getexecname();
+#else
+       return NULL;
+#endif /* HAVE_PROGRAM_INVOCATION_SHORT_NAME */
+}
+#endif /* HAVE_GETPROGNAME */
 
 static void rwrap_log(enum rwrap_dbglvl_e dbglvl, const char *func, const char *format, ...) PRINTF_ATTRIBUTE(3, 4);
 # define RWRAP_LOG(dbglvl, ...) rwrap_log((dbglvl), __func__, __VA_ARGS__)
@@ -87,43 +107,53 @@ static void rwrap_log(enum rwrap_dbglvl_e dbglvl,
        va_list va;
        const char *d;
        unsigned int lvl = 0;
-       int pid = getpid();
+       const char *prefix = NULL;
+       const char *progname = NULL;
 
        d = getenv("RESOLV_WRAPPER_DEBUGLEVEL");
        if (d != NULL) {
                lvl = atoi(d);
        }
 
+       if (lvl < dbglvl) {
+               return;
+       }
+
        va_start(va, format);
        vsnprintf(buffer, sizeof(buffer), format, va);
        va_end(va);
 
-       if (lvl >= dbglvl) {
-               switch (dbglvl) {
-                       case RWRAP_LOG_ERROR:
-                               fprintf(stderr,
-                                       "RWRAP_ERROR(%d) - %s: %s\n",
-                                       pid, func, buffer);
-                               break;
-                       case RWRAP_LOG_WARN:
-                               fprintf(stderr,
-                                       "RWRAP_WARN(%d) - %s: %s\n",
-                                       pid, func, buffer);
-                               break;
-                       case RWRAP_LOG_DEBUG:
-                               fprintf(stderr,
-                                       "RWRAP_DEBUG(%d) - %s: %s\n",
-                                       pid, func, buffer);
-                               break;
-                       case RWRAP_LOG_TRACE:
-                               fprintf(stderr,
-                                       "RWRAP_TRACE(%d) - %s: %s\n",
-                                       pid, func, buffer);
-                               break;
-               }
+       switch (dbglvl) {
+               case RWRAP_LOG_ERROR:
+                       prefix = "RWRAP_ERROR";
+                       break;
+               case RWRAP_LOG_WARN:
+                       prefix = "RWRAP_WARN";
+                       break;
+               case RWRAP_LOG_NOTICE:
+                       prefix = "RWRAP_NOTICE";
+                       break;
+               case RWRAP_LOG_DEBUG:
+                       prefix = "RWRAP_DEBUG";
+                       break;
+               case RWRAP_LOG_TRACE:
+                       prefix = "RWRAP_TRACE";
+                       break;
+       }
+
+       progname = getprogname();
+       if (progname == NULL) {
+               progname = "<unknown>";
        }
+
+       fprintf(stderr,
+               "%s[%s (%u)] - %s: %s\n",
+               prefix,
+               progname,
+               (unsigned int)getpid(),
+               func,
+               buffer);
 }
-#endif /* NDEBUG RWRAP_LOG */
 
 #ifndef SAFE_FREE
 #define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0)
@@ -141,37 +171,287 @@ static void rwrap_log(enum rwrap_dbglvl_e dbglvl,
        }                                                       \
 } while(0);
 
+#define RWRAP_MAX_RECURSION 64
+
+/* Priority and weight can be omitted from the hosts file, but need to be part
+ * of the output
+ */
+#define DFL_SRV_PRIO   1
+#define DFL_SRV_WEIGHT 100
+#define DFL_URI_PRIO   1
+#define DFL_URI_WEIGHT 100
+
+struct rwrap_srv_rrdata {
+       uint16_t port;
+       uint16_t prio;
+       uint16_t weight;
+       char hostname[MAXDNAME];
+};
+
+struct rwrap_uri_rrdata {
+       uint16_t prio;
+       uint16_t weight;
+       char uri[MAXDNAME];
+};
+
+struct rwrap_soa_rrdata {
+       uint32_t serial;
+       uint32_t refresh;
+       uint32_t retry;
+       uint32_t expire;
+       uint32_t minimum;
+       char nameserver[MAXDNAME];
+       char mailbox[MAXDNAME];
+};
+
+struct rwrap_fake_rr {
+       union fake_rrdata {
+               struct in_addr a_rec;
+               struct in6_addr aaaa_rec;
+               struct rwrap_srv_rrdata srv_rec;
+               struct rwrap_uri_rrdata uri_rec;
+               struct rwrap_soa_rrdata soa_rec;
+               char cname_rec[MAXDNAME];
+               char ptr_rec[MAXDNAME];
+               char txt_rec[MAXDNAME];
+       } rrdata;
+
+       char key[MAXDNAME];
+       int type; /* ns_t_* */
+};
+
+static void rwrap_fake_rr_init(struct rwrap_fake_rr *rr, size_t len)
+{
+       size_t i;
+
+       for (i = 0; i < len; i++) {
+               rr[i].type = ns_t_invalid;
+       }
+}
+
+static int rwrap_create_fake_a_rr(const char *key,
+                                 const char *value,
+                                 struct rwrap_fake_rr *rr)
+{
+       int ok;
+
+       ok = inet_pton(AF_INET, value, &rr->rrdata.a_rec);
+       if (!ok) {
+               RWRAP_LOG(RWRAP_LOG_ERROR,
+                         "Failed to convert [%s] to binary\n", value);
+               return -1;
+       }
+
+       memcpy(rr->key, key, strlen(key) + 1);
+       rr->type = ns_t_a;
+       return 0;
+}
+
+static int rwrap_create_fake_aaaa_rr(const char *key,
+                                    const char *value,
+                                    struct rwrap_fake_rr *rr)
+{
+       int ok;
+
+       ok = inet_pton(AF_INET6, value, &rr->rrdata.aaaa_rec);
+       if (!ok) {
+               RWRAP_LOG(RWRAP_LOG_ERROR,
+                         "Failed to convert [%s] to binary\n", value);
+               return -1;
+       }
+
+       memcpy(rr->key, key, strlen(key) + 1);
+       rr->type = ns_t_aaaa;
+       return 0;
+}
+static int rwrap_create_fake_ns_rr(const char *key,
+                                  const char *value,
+                                  struct rwrap_fake_rr *rr)
+{
+       memcpy(rr->rrdata.srv_rec.hostname, value, strlen(value) + 1);
+       memcpy(rr->key, key, strlen(key) + 1);
+       rr->type = ns_t_ns;
+       return 0;
+}
+
+static int rwrap_create_fake_srv_rr(const char *key,
+                                   const char *value,
+                                   struct rwrap_fake_rr *rr)
+{
+       char *str_prio;
+       char *str_weight;
+       char *str_port;
+       const char *hostname;
+
+       /* parse the value into priority, weight, port and hostname
+        * and check the validity */
+       hostname = value;
+       NEXT_KEY(hostname, str_port);
+       NEXT_KEY(str_port, str_prio);
+       NEXT_KEY(str_prio, str_weight);
+       if (str_port == NULL || hostname == NULL) {
+               RWRAP_LOG(RWRAP_LOG_ERROR,
+                         "Malformed SRV entry [%s]\n", value);
+               return -1;
+       }
+
+       if (str_prio) {
+               rr->rrdata.srv_rec.prio = atoi(str_prio);
+       } else {
+               rr->rrdata.srv_rec.prio = DFL_SRV_PRIO;
+       }
+       if (str_weight) {
+               rr->rrdata.srv_rec.weight = atoi(str_weight);
+       } else {
+               rr->rrdata.srv_rec.weight = DFL_SRV_WEIGHT;
+       }
+       rr->rrdata.srv_rec.port = atoi(str_port);
+       memcpy(rr->rrdata.srv_rec.hostname , hostname, strlen(hostname) + 1);
+
+       memcpy(rr->key, key, strlen(key) + 1);
+       rr->type = ns_t_srv;
+       return 0;
+}
+
+static int rwrap_create_fake_uri_rr(const char *key,
+                                   const char *value,
+                                   struct rwrap_fake_rr *rr)
+{
+       char *str_prio;
+       char *str_weight;
+       const char *uri;
+
+       /* parse the value into priority, weight, and uri
+        * and check the validity */
+       uri = value;
+       NEXT_KEY(uri, str_prio);
+       NEXT_KEY(str_prio, str_weight);
+       if (uri == NULL) {
+               RWRAP_LOG(RWRAP_LOG_ERROR,
+                         "Malformed URI entry [<null>]\n");
+               return -1;
+       }
+
+       if (str_prio) {
+               rr->rrdata.uri_rec.prio = atoi(str_prio);
+       } else {
+               rr->rrdata.uri_rec.prio = DFL_URI_PRIO;
+       }
+       if (str_weight) {
+               rr->rrdata.uri_rec.weight = atoi(str_weight);
+       } else {
+               rr->rrdata.uri_rec.weight = DFL_URI_WEIGHT;
+       }
+       memcpy(rr->rrdata.uri_rec.uri, uri, strlen(uri) + 1);
+
+       memcpy(rr->key, key, strlen(key) + 1);
+       rr->type = ns_t_uri;
+       return 0;
+}
+
+static int rwrap_create_fake_txt_rr(const char *key,
+                                   const char *value,
+                                   struct rwrap_fake_rr *rr)
+{
+       memcpy(rr->rrdata.txt_rec, value, strlen(value) + 1);
+
+       memcpy(rr->key, key, strlen(key) + 1);
+       rr->type = ns_t_txt;
+       return 0;
+}
+
+static int rwrap_create_fake_soa_rr(const char *key,
+                                   const char *value,
+                                   struct rwrap_fake_rr *rr)
+{
+       const char *nameserver;
+       char *mailbox;
+       char *str_serial;
+       char *str_refresh;
+       char *str_retry;
+       char *str_expire;
+       char *str_minimum;
+
+       /* parse the value into nameserver, mailbox, serial, refresh,
+        * retry, expire, minimum and check the validity
+        */
+       nameserver = value;
+       NEXT_KEY(nameserver, mailbox);
+       NEXT_KEY(mailbox, str_serial);
+       NEXT_KEY(str_serial, str_refresh);
+       NEXT_KEY(str_refresh, str_retry);
+       NEXT_KEY(str_retry, str_expire);
+       NEXT_KEY(str_expire, str_minimum);
+       if (nameserver == NULL || mailbox == NULL || str_serial == NULL ||
+           str_refresh == NULL || str_retry == NULL || str_expire == NULL ||
+           str_minimum == NULL) {
+               RWRAP_LOG(RWRAP_LOG_ERROR,
+                         "Malformed SOA entry [%s]\n", value);
+               return -1;
+       }
+
+       memcpy(rr->rrdata.soa_rec.nameserver, nameserver, strlen(nameserver)+1);
+       memcpy(rr->rrdata.soa_rec.mailbox, mailbox, strlen(mailbox)+1);
+
+       rr->rrdata.soa_rec.serial = atoi(str_serial);
+       rr->rrdata.soa_rec.refresh = atoi(str_refresh);
+       rr->rrdata.soa_rec.retry = atoi(str_retry);
+       rr->rrdata.soa_rec.expire = atoi(str_expire);
+       rr->rrdata.soa_rec.minimum = atoi(str_minimum);
+
+       memcpy(rr->key, key, strlen(key) + 1);
+       rr->type = ns_t_soa;
+       return 0;
+}
+
+static int rwrap_create_fake_cname_rr(const char *key,
+                                     const char *value,
+                                     struct rwrap_fake_rr *rr)
+{
+       memcpy(rr->rrdata.cname_rec , value, strlen(value) + 1);
+       memcpy(rr->key, key, strlen(key) + 1);
+       rr->type = ns_t_cname;
+       return 0;
+}
+
+static int rwrap_create_fake_ptr_rr(const char *key,
+                                   const char *value,
+                                   struct rwrap_fake_rr *rr)
+{
+       memcpy(rr->rrdata.ptr_rec , value, strlen(value) + 1);
+       memcpy(rr->key, key, strlen(key) + 1);
+       rr->type = ns_t_ptr;
+       return 0;
+}
 
 /* Prepares a fake header with a single response. Advances header_blob */
 static ssize_t rwrap_fake_header(uint8_t **header_blob, size_t remaining,
-                                size_t rdata_size)
+                                size_t ancount, size_t arcount)
 {
-       uint8_t *hb;
-       HEADER *h;
-       int answers;
-
-       /* If rdata_size is zero, the answer is empty */
-       answers = rdata_size > 0 ? 1 : 0;
+       union {
+               uint8_t *blob;
+               HEADER *header;
+       } h;
 
        if (remaining < NS_HFIXEDSZ) {
                RWRAP_LOG(RWRAP_LOG_ERROR, "Buffer too small!\n");
                return -1;
        }
 
-       hb = *header_blob;
-       memset(hb, 0, NS_HFIXEDSZ);
+       h.blob = *header_blob;
+       memset(h.blob, 0, NS_HFIXEDSZ);
 
-       h = (HEADER *) hb;
-       h->id = res_randomid();         /* random query ID */
-       h->qr = 1;                      /* response flag */
-       h->rd = 1;                      /* recursion desired */
-       h->ra = 1;                      /* resursion available */
+       h.header->id = res_randomid();          /* random query ID */
+       h.header->qr = 1;                       /* response flag */
+       h.header->rd = 1;                       /* recursion desired */
+       h.header->ra = 1;                       /* recursion available */
 
-       h->qdcount = htons(1);          /* no. of questions */
-       h->ancount = htons(answers);    /* no. of answers */
+       h.header->qdcount = htons(1);           /* no. of questions */
+       h.header->ancount = htons(ancount);     /* no. of answers */
+       h.header->arcount = htons(arcount);     /* no. of add'tl records */
 
-       hb += NS_HFIXEDSZ;              /* move past the header */
-       *header_blob = hb;
+       /* move past the header */
+       *header_blob = h.blob += NS_HFIXEDSZ;
 
        return NS_HFIXEDSZ;
 }
@@ -240,147 +520,116 @@ static ssize_t rwrap_fake_rdata_common(uint16_t type,
        }
 
        *rdata_ptr = rd;
-       return written + 3 * sizeof(uint16_t) + sizeof(uint32_t);
+       return written + 3 * sizeof(uint16_t) + sizeof(uint32_t) + rdata_size;
 }
 
-static ssize_t rwrap_fake_common(uint16_t type,
-                                const char *question,
-                                size_t rdata_size,
-                                uint8_t **answer_ptr,
-                                size_t anslen)
+static ssize_t rwrap_fake_a(struct rwrap_fake_rr *rr,
+                           uint8_t *answer_ptr,
+                           size_t anslen)
 {
-       uint8_t *a = *answer_ptr;
-       ssize_t written;
-       size_t remaining;
-
-       remaining = anslen;
+       uint8_t *a = answer_ptr;
+       ssize_t resp_size;
 
-       written = rwrap_fake_header(&a, remaining, rdata_size);
-       if (written < 0) {
+       if (rr->type != ns_t_a) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
                return -1;
        }
-       remaining -= written;
+       RWRAP_LOG(RWRAP_LOG_TRACE, "Adding A RR");
 
-       written = rwrap_fake_question(question, type, &a, remaining);
-       if (written < 0) {
+       resp_size = rwrap_fake_rdata_common(ns_t_a, sizeof(struct in_addr), rr->key,
+                                           anslen, &a);
+       if (resp_size < 0) {
                return -1;
        }
-       remaining -= written;
 
-       /* rdata_size = 0 denotes an empty answer */
-       if (rdata_size > 0) {
-               written = rwrap_fake_rdata_common(type, rdata_size, question,
-                                               remaining, &a);
-               if (written < 0) {
-                       return -1;
-               }
-       }
+       memcpy(a, &rr->rrdata.a_rec, sizeof(struct in_addr));
 
-       *answer_ptr = a;
-       return written;
+       return resp_size;
 }
 
-static int rwrap_fake_a(const char *key,
-                       const char *value,
-                       uint8_t *answer_ptr,
-                       size_t anslen)
+static ssize_t rwrap_fake_aaaa(struct rwrap_fake_rr *rr,
+                              uint8_t *answer,
+                              size_t anslen)
 {
-       uint8_t *a = answer_ptr;
-       struct in_addr a_rec;
-       int rc;
-       int ok;
+       uint8_t *a = answer;
+       ssize_t resp_size;
 
-       if (value == NULL) {
-               RWRAP_LOG(RWRAP_LOG_ERROR, "Malformed record, no value!\n");
+       if (rr->type != ns_t_aaaa) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
                return -1;
        }
+       RWRAP_LOG(RWRAP_LOG_TRACE, "Adding AAAA RR");
 
-       rc = rwrap_fake_common(ns_t_a, key, sizeof(a_rec), &a, anslen);
-       if (rc < 0) {
+       resp_size = rwrap_fake_rdata_common(ns_t_aaaa, sizeof(struct in6_addr),
+                                           rr->key, anslen, &a);
+       if (resp_size < 0) {
                return -1;
        }
 
-       ok = inet_pton(AF_INET, value, &a_rec);
-       if (!ok) {
-               RWRAP_LOG(RWRAP_LOG_ERROR,
-                         "Failed to convert [%s] to binary\n", value);
-               return -1;
-       }
-       memcpy(a, &a_rec, sizeof(struct in_addr));
+       memcpy(a, &rr->rrdata.aaaa_rec, sizeof(struct in6_addr));
 
-       return 0;
+       return resp_size;
 }
 
-static int rwrap_fake_aaaa(const char *key,
-                          const char *value,
-                          uint8_t *answer,
-                          size_t anslen)
+static ssize_t rwrap_fake_ns(struct rwrap_fake_rr *rr,
+                            uint8_t *answer,
+                           size_t anslen)
 {
        uint8_t *a = answer;
-       struct in6_addr aaaa_rec;
-       int rc;
-       int ok;
+       ssize_t resp_size = 0;
+       size_t rdata_size;
+       unsigned char hostname_compressed[MAXDNAME];
+       ssize_t compressed_len;
 
-       if (value == NULL) {
-               RWRAP_LOG(RWRAP_LOG_ERROR, "Malformed record, no value!\n");
+       if (rr->type != ns_t_ns) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
                return -1;
        }
+       RWRAP_LOG(RWRAP_LOG_TRACE, "Adding NS RR");
 
-       rc = rwrap_fake_common(ns_t_aaaa, key, sizeof(aaaa_rec), &a, anslen);
-       if (rc < 0) {
+       /* Prepare the data to write */
+       compressed_len = ns_name_compress(rr->rrdata.srv_rec.hostname,
+                                         hostname_compressed,
+                                         MAXDNAME,
+                                         NULL,
+                                         NULL);
+       if (compressed_len < 0) {
                return -1;
        }
 
-       ok = inet_pton(AF_INET6, value, &aaaa_rec);
-       if (!ok) {
-               RWRAP_LOG(RWRAP_LOG_ERROR,
-                         "Failed to convert [%s] to binary\n", value);
+       /* Is this enough? */
+       rdata_size = compressed_len;
+
+       resp_size = rwrap_fake_rdata_common(ns_t_ns, rdata_size,
+                                           rr->key, anslen, &a);
+       if (resp_size < 0) {
                return -1;
        }
-       memcpy(a, &aaaa_rec, sizeof(struct in6_addr));
 
-       return 0;
-}
+       memcpy(a, hostname_compressed, compressed_len);
 
-/*
- * Priority and weight can be omitted from the hosts file, but need to be part
- * of the output
- */
-#define DFL_SRV_PRIO   1
-#define DFL_SRV_WEIGHT 100
+       return resp_size;
+}
 
-static int rwrap_fake_srv(const char *key,
-                         const char *value,
-                         uint8_t *answer,
-                         size_t anslen)
+static ssize_t rwrap_fake_srv(struct rwrap_fake_rr *rr,
+                             uint8_t *answer,
+                             size_t anslen)
 {
        uint8_t *a = answer;
-       int rv;
+       ssize_t resp_size;
        size_t rdata_size;
-       char *str_prio;
-       char *str_weight;
-       char *str_port;
-       const char *hostname;
        unsigned char hostname_compressed[MAXDNAME];
        ssize_t compressed_len;
 
-       /*
-        * Parse the value into priority, weight, port and hostname
-        * and check the validity.
-        */
-       hostname = value;
-       NEXT_KEY(hostname, str_port);
-       NEXT_KEY(str_port, str_prio);
-       NEXT_KEY(str_prio, str_weight);
-       if (str_port == NULL || hostname == NULL) {
-               RWRAP_LOG(RWRAP_LOG_ERROR,
-                         "Malformed SRV entry [%s]\n", value);
+       if (rr->type != ns_t_srv) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
                return -1;
        }
+       RWRAP_LOG(RWRAP_LOG_TRACE, "Adding SRV RR");
        rdata_size = 3 * sizeof(uint16_t);
 
        /* Prepare the data to write */
-       compressed_len = ns_name_compress(hostname,
+       compressed_len = ns_name_compress(rr->rrdata.srv_rec.hostname,
                                          hostname_compressed, MAXDNAME,
                                          NULL, NULL);
        if (compressed_len < 0) {
@@ -388,84 +637,117 @@ static int rwrap_fake_srv(const char *key,
        }
        rdata_size += compressed_len;
 
-       rv = rwrap_fake_common(ns_t_srv, key, rdata_size, &a, anslen);
-       if (rv < 0) {
+       resp_size = rwrap_fake_rdata_common(ns_t_srv, rdata_size,
+                                           rr->key, anslen, &a);
+       if (resp_size < 0) {
                return -1;
        }
 
-       if (str_prio) {
-               NS_PUT16(atoi(str_prio), a);
-       } else {
-               NS_PUT16(DFL_SRV_PRIO, a);
+       NS_PUT16(rr->rrdata.srv_rec.prio, a);
+       NS_PUT16(rr->rrdata.srv_rec.weight, a);
+       NS_PUT16(rr->rrdata.srv_rec.port, a);
+       memcpy(a, hostname_compressed, compressed_len);
+
+       return resp_size;
+}
+
+static ssize_t rwrap_fake_uri(struct rwrap_fake_rr *rr,
+                             uint8_t *answer,
+                             size_t anslen)
+{
+       uint8_t *a = answer;
+       ssize_t resp_size;
+       size_t rdata_size;
+       size_t uri_len;
+
+       if (rr->type != ns_t_uri) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
+               return -1;
        }
-       if (str_weight) {
-               NS_PUT16(atoi(str_weight), a);
-       } else {
-               NS_PUT16(DFL_SRV_WEIGHT, a);
+       RWRAP_LOG(RWRAP_LOG_TRACE, "Adding URI RR");
+       rdata_size = 3 * sizeof(uint16_t);
+       uri_len = strlen(rr->rrdata.uri_rec.uri) + 1;
+       rdata_size += uri_len;
+
+       resp_size = rwrap_fake_rdata_common(ns_t_uri, rdata_size,
+                                           rr->key, anslen, &a);
+       if (resp_size < 0) {
+               return -1;
        }
-       NS_PUT16(atoi(str_port), a);
-       memcpy(a, hostname_compressed, compressed_len);
 
-       return 0;
+       NS_PUT16(rr->rrdata.uri_rec.prio, a);
+       NS_PUT16(rr->rrdata.uri_rec.weight, a);
+       memcpy(a, rr->rrdata.uri_rec.uri, uri_len);
+
+       return resp_size;
 }
 
-static int rwrap_fake_soa(const char *key,
-                         const char *value,
-                         uint8_t *answer,
-                         size_t anslen)
+static ssize_t rwrap_fake_txt(struct rwrap_fake_rr *rr,
+                             uint8_t *answer,
+                             size_t anslen)
 {
        uint8_t *a = answer;
-       int rv;
-       const char *nameserver;
-       char *mailbox;
-       char *str_serial;
-       char *str_refresh;
-       char *str_retry;
-       char *str_expire;
-       char *str_minimum;
+       ssize_t resp_size;
+       size_t rdata_size;
+       size_t txt_len;
+
+       if (rr->type != ns_t_txt) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
+               return -1;
+       }
+       RWRAP_LOG(RWRAP_LOG_TRACE, "Adding TXT RR");
+       txt_len = strlen(rr->rrdata.txt_rec) + 1;
+       rdata_size = txt_len;
+
+       resp_size = rwrap_fake_rdata_common(ns_t_txt, rdata_size,
+                                           rr->key, anslen, &a);
+       if (resp_size < 0) {
+               return -1;
+       }
+
+       memcpy(a, rr->rrdata.txt_rec, txt_len);
+
+       return resp_size;
+}
+
+static ssize_t rwrap_fake_soa(struct rwrap_fake_rr *rr,
+                             uint8_t *answer,
+                             size_t anslen)
+{
+       uint8_t *a = answer;
+       ssize_t resp_size;
        size_t rdata_size;
        unsigned char nameser_compressed[MAXDNAME];
        ssize_t compressed_ns_len;
        unsigned char mailbox_compressed[MAXDNAME];
        ssize_t compressed_mb_len;
 
-       /*
-        * parse the value into nameserver, mailbox, serial, refresh,
-        * retry, expire, minimum and check the validity
-        */
-       nameserver = value;
-       NEXT_KEY(nameserver, mailbox);
-       NEXT_KEY(mailbox, str_serial);
-       NEXT_KEY(str_serial, str_refresh);
-       NEXT_KEY(str_refresh, str_retry);
-       NEXT_KEY(str_retry, str_expire);
-       NEXT_KEY(str_expire, str_minimum);
-       if (nameserver == NULL || mailbox == NULL || str_serial == NULL ||
-           str_refresh == NULL || str_retry == NULL || str_expire == NULL ||
-           str_minimum == NULL)
-       {
-               RWRAP_LOG(RWRAP_LOG_ERROR,
-                         "Malformed SOA entry [%s]\n", value);
+       if (rr->type != ns_t_soa) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
                return -1;
        }
+       RWRAP_LOG(RWRAP_LOG_TRACE, "Adding SOA RR");
        rdata_size = 5 * sizeof(uint16_t);
 
-       compressed_ns_len = ns_name_compress(nameserver, nameser_compressed,
+       compressed_ns_len = ns_name_compress(rr->rrdata.soa_rec.nameserver,
+                                            nameser_compressed,
                                             MAXDNAME, NULL, NULL);
        if (compressed_ns_len < 0) {
                return -1;
        }
        rdata_size += compressed_ns_len;
 
-       compressed_mb_len = ns_name_compress(mailbox, mailbox_compressed,
+       compressed_mb_len = ns_name_compress(rr->rrdata.soa_rec.mailbox,
+                                            mailbox_compressed,
                                             MAXDNAME, NULL, NULL);
        if (compressed_mb_len < 0) {
                return -1;
        }
        rdata_size += compressed_mb_len;
 
-       rv = rwrap_fake_common(ns_t_soa, key, rdata_size, &a, anslen);
-       if (rv < 0) {
+       resp_size = rwrap_fake_rdata_common(ns_t_soa, rdata_size,
+                                           rr->key, anslen, &a);
+       if (resp_size < 0) {
                return -1;
        }
 
@@ -473,61 +755,81 @@ static int rwrap_fake_soa(const char *key,
        a += compressed_ns_len;
        memcpy(a, mailbox_compressed, compressed_mb_len);
        a += compressed_mb_len;
-       NS_PUT32(atoi(str_serial), a);
-       NS_PUT32(atoi(str_refresh), a);
-       NS_PUT32(atoi(str_retry), a);
-       NS_PUT32(atoi(str_expire), a);
-       NS_PUT32(atoi(str_minimum), a);
+       NS_PUT32(rr->rrdata.soa_rec.serial, a);
+       NS_PUT32(rr->rrdata.soa_rec.refresh, a);
+       NS_PUT32(rr->rrdata.soa_rec.retry, a);
+       NS_PUT32(rr->rrdata.soa_rec.expire, a);
+       NS_PUT32(rr->rrdata.soa_rec.minimum, a);
 
-       return 0;
+       return resp_size;
 }
 
-static int rwrap_fake_cname(const char *key,
-                           const char *value,
-                           uint8_t *answer,
-                           size_t anslen)
+static ssize_t rwrap_fake_cname(struct rwrap_fake_rr *rr,
+                               uint8_t *answer,
+                               size_t anslen)
 {
        uint8_t *a = answer;
-       int rv;
+       ssize_t resp_size;
        unsigned char hostname_compressed[MAXDNAME];
        ssize_t rdata_size;
 
-       if (value == NULL) {
-               RWRAP_LOG(RWRAP_LOG_ERROR, "Malformed record, no value!\n");
+       if (rr->type != ns_t_cname) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
                return -1;
        }
+       RWRAP_LOG(RWRAP_LOG_TRACE, "Adding CNAME RR");
 
        /* Prepare the data to write */
-       rdata_size = ns_name_compress(value,
+       rdata_size = ns_name_compress(rr->rrdata.cname_rec,
                                      hostname_compressed, MAXDNAME,
                                      NULL, NULL);
        if (rdata_size < 0) {
                return -1;
        }
 
-       rv = rwrap_fake_common(ns_t_cname, key, rdata_size, &a, anslen);
-       if (rv < 0) {
+       resp_size = rwrap_fake_rdata_common(ns_t_cname, rdata_size,
+                                           rr->key, anslen, &a);
+       if (resp_size < 0) {
                return -1;
        }
 
        memcpy(a, hostname_compressed, rdata_size);
 
-       return 0;
+       return resp_size;
 }
 
-static int rwrap_fake_empty_query(const char *key,
-                                 uint16_t type,
-                                 uint8_t *answer,
-                                 size_t anslen)
+static ssize_t rwrap_fake_ptr(struct rwrap_fake_rr *rr,
+                             uint8_t *answer,
+                             size_t anslen)
 {
-       int rc;
+       uint8_t *a = answer;
+       ssize_t rdata_size;
+       ssize_t resp_size;
+       unsigned char hostname_compressed[MAXDNAME];
 
-       rc = rwrap_fake_common(type, key, 0, &answer, anslen);
-       if (rc < 0) {
+       if (rr->type != ns_t_ptr) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
                return -1;
        }
+       RWRAP_LOG(RWRAP_LOG_TRACE, "Adding PTR RR");
 
-       return 0;
+       /* Prepare the data to write */
+       rdata_size = ns_name_compress(rr->rrdata.ptr_rec,
+                                     hostname_compressed, MAXDNAME,
+                                     NULL, NULL);
+       if (rdata_size < 0) {
+               return -1;
+       }
+
+       resp_size = rwrap_fake_rdata_common(ns_t_ptr, rdata_size,
+                                           rr->key, anslen, &a);
+       if (resp_size < 0) {
+               return -1;
+       }
+
+       memcpy(a, hostname_compressed, rdata_size);
+
+       return resp_size;
 }
 
 #define RESOLV_MATCH(line, name) \
@@ -538,33 +840,80 @@ static int rwrap_fake_empty_query(const char *key,
 #define TYPE_MATCH(type, ns_type, rec_type, str_type, key, query) \
        ((type) == (ns_type) && \
         (strncmp((rec_type), (str_type), sizeof(str_type)) == 0) && \
-        (strcmp(key, query)) == 0)
+        (strcasecmp(key, query)) == 0)
 
 
-/* Reads in a file in the following format:
- * TYPE RDATA
- *
- * Malformed entried are silently skipped.
- * Allocates answer buffer of size anslen that has to be freed after use.
- */
-static int rwrap_res_fake_hosts(const char *hostfile,
-                               const char *query,
-                               int type,
-                               unsigned char *answer,
-                               size_t anslen)
+static int rwrap_get_record(const char *hostfile, unsigned recursion,
+                           const char *query, int type,
+                           struct rwrap_fake_rr *rr);
+
+static int rwrap_uri_recurse(const char *hostfile, unsigned recursion,
+                            const char *query, struct rwrap_fake_rr *rr)
+{
+       int rc;
+
+       rc = rwrap_get_record(hostfile, recursion, query, ns_t_uri, rr);
+       if (rc == ENOENT) {
+               rc = 0;
+       }
+
+       return rc;
+}
+
+static int rwrap_srv_recurse(const char *hostfile, unsigned recursion,
+                            const char *query, struct rwrap_fake_rr *rr)
+{
+       int rc;
+
+       rc = rwrap_get_record(hostfile, recursion, query, ns_t_a, rr);
+       if (rc == 0) return 0;
+
+       rc = rwrap_get_record(hostfile, recursion, query, ns_t_aaaa, rr);
+       if (rc == ENOENT) rc = 0;
+
+       return rc;
+}
+
+static int rwrap_cname_recurse(const char *hostfile, unsigned recursion,
+                              const char *query, struct rwrap_fake_rr *rr)
+{
+       int rc;
+
+       rc = rwrap_get_record(hostfile, recursion, query, ns_t_a, rr);
+       if (rc == 0) return 0;
+
+       rc = rwrap_get_record(hostfile, recursion, query, ns_t_aaaa, rr);
+       if (rc == 0) return 0;
+
+       rc = rwrap_get_record(hostfile, recursion, query, ns_t_cname, rr);
+       if (rc == ENOENT) rc = 0;
+
+       return rc;
+}
+
+static int rwrap_get_record(const char *hostfile, unsigned recursion,
+                           const char *query, int type,
+                           struct rwrap_fake_rr *rr)
 {
        FILE *fp = NULL;
        char buf[BUFSIZ];
-       int rc = ENOENT;
        char *key = NULL;
        char *value = NULL;
+       int rc = ENOENT;
+       unsigned num_uris = 0;
+
+       if (recursion >= RWRAP_MAX_RECURSION) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Recursed too deep!\n");
+               return -1;
+       }
 
        RWRAP_LOG(RWRAP_LOG_TRACE,
-                 "Searching in fake hosts file %s\n", hostfile);
+                 "Searching in fake hosts file %s for %s:%d\n", hostfile,
+                 query, type);
 
        fp = fopen(hostfile, "r");
        if (fp == NULL) {
-               RWRAP_LOG(RWRAP_LOG_ERROR,
+               RWRAP_LOG(RWRAP_LOG_WARN,
                          "Opening %s failed: %s",
                          hostfile, strerror(errno));
                return -1;
@@ -580,59 +929,363 @@ static int rwrap_res_fake_hosts(const char *hostfile,
                NEXT_KEY(rec_type, key);
                NEXT_KEY(key, value);
 
+               if (key == NULL || value == NULL) {
+                       RWRAP_LOG(RWRAP_LOG_WARN,
+                               "Malformed line: not enough parts, use \"rec_type key data\n"
+                               "For example \"A cwrap.org 10.10.10.10\"");
+                       continue;
+               }
+
                q = value;
                while(q[0] != '\n' && q[0] != '\0') {
                        q++;
                }
                q[0] = '\0';
 
-               if (key == NULL || value == NULL) {
-                       RWRAP_LOG(RWRAP_LOG_WARN,
-                               "Malformed line: not enough parts, use \"rec_type key data\n"
-                               "For example \"A cwrap.org 10.10.10.10\"");
-                       continue;
+               if (type == ns_t_uri && recursion > 0) {
+                       /* Skip non-URI records. */
+                       if (!TYPE_MATCH(type, ns_t_uri, rec_type, "URI", key, query)) {
+                               continue;
+                       }
+                       /* Skip previous records based on the recurse depth. */
+                       num_uris++;
+                       if (num_uris <= recursion) {
+                               continue;
+                       }
                }
 
                if (TYPE_MATCH(type, ns_t_a, rec_type, "A", key, query)) {
-                       rc = rwrap_fake_a(key, value, answer, anslen);
+                       rc = rwrap_create_fake_a_rr(key, value, rr);
                        break;
                } else if (TYPE_MATCH(type, ns_t_aaaa,
                                      rec_type, "AAAA", key, query)) {
-                       rc = rwrap_fake_aaaa(key, value, answer, anslen);
+                       rc = rwrap_create_fake_aaaa_rr(key, value, rr);
+                       break;
+               } else if (TYPE_MATCH(type, ns_t_ns,
+                                     rec_type, "NS", key, query)) {
+                       rc = rwrap_create_fake_ns_rr(key, value, rr);
                        break;
                } else if (TYPE_MATCH(type, ns_t_srv,
                                      rec_type, "SRV", key, query)) {
-                       rc = rwrap_fake_srv(key, value, answer, anslen);
+                       rc = rwrap_create_fake_srv_rr(key, value, rr);
+                       if (rc == 0) {
+                               rc = rwrap_srv_recurse(hostfile, recursion+1,
+                                               rr->rrdata.srv_rec.hostname,
+                                               rr + 1);
+                       }
+                       break;
+               } else if (TYPE_MATCH(type, ns_t_uri,
+                                     rec_type, "URI", key, query)) {
+                       rc = rwrap_create_fake_uri_rr(key, value, rr);
+                       if (rc == 0) {
+                               /* Recurse to collect multiple URI answers under a single key. */
+                               rc = rwrap_uri_recurse(hostfile, recursion + 1, key, rr + 1);
+                       }
                        break;
                } else if (TYPE_MATCH(type, ns_t_soa,
                                      rec_type, "SOA", key, query)) {
-                       rc = rwrap_fake_soa(key, value, answer, anslen);
+                       rc = rwrap_create_fake_soa_rr(key, value, rr);
                        break;
                } else if (TYPE_MATCH(type, ns_t_cname,
                                      rec_type, "CNAME", key, query)) {
-                       rc = rwrap_fake_cname(key, value, answer, anslen);
+                       rc = rwrap_create_fake_cname_rr(key, value, rr);
+                       if (rc == 0) {
+                               rc = rwrap_cname_recurse(hostfile, recursion+1,
+                                                        value, rr + 1);
+                       }
+                       break;
+               } else if (TYPE_MATCH(type, ns_t_a, rec_type, "CNAME", key, query)) {
+                       rc = rwrap_create_fake_cname_rr(key, value, rr);
+                       if (rc == 0) {
+                               rc = rwrap_cname_recurse(hostfile, recursion+1,
+                                                        value, rr + 1);
+                       }
+                       break;
+               } else if (TYPE_MATCH(type, ns_t_ptr,
+                                     rec_type, "PTR", key, query)) {
+                       rc = rwrap_create_fake_ptr_rr(key, value, rr);
+                       break;
+               }
+               else if (TYPE_MATCH(type, ns_t_txt,
+                                     rec_type, "TXT", key, query)) {
+                       rc = rwrap_create_fake_txt_rr(key, value, rr);
+                       break;
+               }
+       }
+
+       if (rc == ENOENT && recursion == 0 && key != NULL) {
+               RWRAP_LOG(RWRAP_LOG_TRACE, "Record for [%s] not found\n", query);
+               memcpy(rr->key, key, strlen(key) + 1);
+       }
+
+       fclose(fp);
+       return rc;
+}
+
+static ssize_t rwrap_fake_empty(int type,
+                               const char *question,
+                               uint8_t *answer,
+                               size_t anslen)
+{
+       ssize_t resp_data;
+       size_t remaining = anslen;
+
+       resp_data = rwrap_fake_header(&answer, remaining, 0, 0);
+       if (resp_data < 0) {
+               return -1;
+       }
+       remaining -= resp_data;
+
+       resp_data += rwrap_fake_question(question, type, &answer, remaining);
+       if (resp_data < 0) {
+               return -1;
+       }
+       remaining -= resp_data;
+
+       resp_data += rwrap_fake_rdata_common(type, 0, question,
+                                           remaining, &answer);
+       if (resp_data < 0) {
+               return -1;
+       }
+
+       return resp_data;
+}
+
+static inline bool rwrap_known_type(int type)
+{
+       switch (type) {
+       case ns_t_a:
+       case ns_t_aaaa:
+       case ns_t_ns:
+       case ns_t_srv:
+       case ns_t_uri:
+       case ns_t_soa:
+       case ns_t_cname:
+       case ns_t_ptr:
+       case ns_t_txt:
+               return true;
+       }
+
+       return false;
+}
+
+static int rwrap_ancount(struct rwrap_fake_rr *rrs, int qtype)
+{
+       int i;
+       int ancount = 0;
+
+       /* For URI return the number of URIs. */
+       if (qtype == ns_t_uri) {
+               for (i = 0; i < RWRAP_MAX_RECURSION; i++) {
+                       if (rwrap_known_type(rrs[i].type) &&
+                           rrs[i].type == qtype) {
+                               ancount++;
+                       }
+               }
+               return ancount;
+       }
+
+       /* Include all RRs in the stack until the sought type
+        * in the answer section. This is the case i.e. when looking
+        * up an A record but the name points to a CNAME
+        */
+       for (i = 0; i < RWRAP_MAX_RECURSION; i++) {
+               ancount++;
+
+               if (rwrap_known_type(rrs[i].type) &&
+                   rrs[i].type == qtype) {
                        break;
                }
        }
 
+       /* Return 0 records if the sought type wasn't in the stack */
+       return i < RWRAP_MAX_RECURSION ? ancount : 0;
+}
+
+static int rwrap_arcount(struct rwrap_fake_rr *rrs, int ancount)
+{
+       int i;
+       int arcount = 0;
+
+       /* start from index ancount */
+       for (i = ancount; i < RWRAP_MAX_RECURSION; i++) {
+               if (rwrap_known_type(rrs[i].type)) {
+                       arcount++;
+               }
+       }
+
+       return arcount;
+}
+
+static ssize_t rwrap_add_rr(struct rwrap_fake_rr *rr,
+                           uint8_t *answer,
+                           size_t anslen)
+{
+       ssize_t resp_data;
+
+       if (rr == NULL) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Internal error!\n");
+               return -1;
+       }
+
+       switch (rr->type) {
+       case ns_t_a:
+               resp_data = rwrap_fake_a(rr, answer, anslen);
+               break;
+       case ns_t_aaaa:
+               resp_data = rwrap_fake_aaaa(rr, answer, anslen);
+               break;
+       case ns_t_ns:
+               resp_data = rwrap_fake_ns(rr, answer, anslen);
+               break;
+       case ns_t_srv:
+               resp_data = rwrap_fake_srv(rr, answer, anslen);
+               break;
+       case ns_t_uri:
+               resp_data = rwrap_fake_uri(rr, answer, anslen);
+               break;
+       case ns_t_soa:
+               resp_data = rwrap_fake_soa(rr, answer, anslen);
+               break;
+       case ns_t_cname:
+               resp_data = rwrap_fake_cname(rr, answer, anslen);
+               break;
+       case ns_t_ptr:
+               resp_data = rwrap_fake_ptr(rr, answer, anslen);
+               break;
+       case ns_t_txt:
+               resp_data = rwrap_fake_txt(rr, answer, anslen);
+               break;
+       default:
+               return -1;
+       }
+
+       return resp_data;
+}
+
+static ssize_t rwrap_fake_answer(struct rwrap_fake_rr *rrs,
+                                int type,
+                                uint8_t *answer,
+                                size_t anslen)
+
+{
+       ssize_t resp_data;
+       ssize_t rrlen;
+       size_t remaining = anslen;
+       int ancount;
+       int arcount;
+       int i;
+
+       ancount = rwrap_ancount(rrs, type);
+       arcount = rwrap_arcount(rrs, ancount);
+       RWRAP_LOG(RWRAP_LOG_TRACE,
+                 "Got %d answers and %d additional records\n", ancount, arcount);
+
+       resp_data = rwrap_fake_header(&answer, remaining, ancount, arcount);
+       if (resp_data < 0) {
+               return -1;
+       }
+       remaining -= resp_data;
+
+       resp_data += rwrap_fake_question(rrs->key, rrs->type, &answer, remaining);
+       if (resp_data < 0) {
+               return -1;
+       }
+       remaining -= resp_data;
+
+       /* answer */
+       for (i = 0; i < ancount; i++) {
+               rrlen = rwrap_add_rr(&rrs[i], answer, remaining);
+               if (rrlen < 0) {
+                       return -1;
+               }
+               remaining -= rrlen;
+               answer += rrlen;
+               resp_data += rrlen;
+       }
+
+       /* add authoritative NS here? */
+
+       /* additional records */
+       for (i = ancount; i < ancount + arcount; i++) {
+               rrlen = rwrap_add_rr(&rrs[i], answer, remaining);
+               if (rrlen < 0) {
+                       return -1;
+               }
+               remaining -= rrlen;
+               answer += rrlen;
+               resp_data += rrlen;
+       }
+
+       return resp_data;
+}
+
+/* Reads in a file in the following format:
+ * TYPE RDATA
+ *
+ * Malformed entries are silently skipped.
+ * Allocates answer buffer of size anslen that has to be freed after use.
+ */
+static int rwrap_res_fake_hosts(const char *hostfile,
+                               const char *query,
+                               int type,
+                               unsigned char *answer,
+                               size_t anslen)
+{
+       int rc = ENOENT;
+       char *query_name = NULL;
+       size_t qlen = strlen(query);
+       struct rwrap_fake_rr rrs[RWRAP_MAX_RECURSION];
+       ssize_t resp_size;
+
+       RWRAP_LOG(RWRAP_LOG_TRACE,
+                 "Searching in fake hosts file %s\n", hostfile);
+
+       if (qlen > 0 && query[qlen-1] == '.') {
+               qlen--;
+       }
+
+       query_name = strndup(query, qlen);
+       if (query_name == NULL) {
+               return -1;
+       }
+
+       rwrap_fake_rr_init(rrs, RWRAP_MAX_RECURSION);
+
+       rc = rwrap_get_record(hostfile, 0, query_name, type, rrs);
        switch (rc) {
        case 0:
                RWRAP_LOG(RWRAP_LOG_TRACE,
-                               "Successfully faked answer for [%s]\n", query);
+                               "Found record for [%s]\n", query_name);
+               resp_size = rwrap_fake_answer(rrs, type, answer, anslen);
                break;
+       case ENOENT:
+               RWRAP_LOG(RWRAP_LOG_TRACE,
+                               "No record for [%s]\n", query_name);
+               resp_size = rwrap_fake_empty(type, rrs->key, answer, anslen);
+               break;
+       default:
+               RWRAP_LOG(RWRAP_LOG_NOTICE,
+                         "Searching for [%s] did not return any results\n",
+                         query_name);
+               free(query_name);
+               return -1;
+       }
+
+       switch (resp_size) {
        case -1:
                RWRAP_LOG(RWRAP_LOG_ERROR,
-                               "Error faking answer for [%s]\n", query);
+                               "Error faking answer for [%s]\n", query_name);
                break;
-       case ENOENT:
+       default:
                RWRAP_LOG(RWRAP_LOG_TRACE,
-                               "Record for [%s] not found\n", query);
-               rc = rwrap_fake_empty_query(key, type, answer, anslen);
+                               "Successfully faked answer for [%s]\n",
+                               query_name);
                break;
        }
 
-       fclose(fp);
-       return rc;
+       free(query_name);
+       return resp_size;
 }
 
 /*********************************************************
@@ -641,51 +1294,68 @@ static int rwrap_res_fake_hosts(const char *hostfile,
 
 #include <dlfcn.h>
 
-struct rwrap_libc_fns {
-       int (*libc_res_init)(void);
-       int (*libc___res_init)(void);
-       int (*libc_res_ninit)(struct __res_state *state);
-       int (*libc___res_ninit)(struct __res_state *state);
-       void (*libc_res_nclose)(struct __res_state *state);
-       void (*libc___res_nclose)(struct __res_state *state);
-       void (*libc_res_close)(void);
-       void (*libc___res_close)(void);
-       int (*libc_res_nquery)(struct __res_state *state,
-                              const char *dname,
-                              int class,
-                              int type,
-                              unsigned char *answer,
-                              int anslen);
-       int (*libc___res_nquery)(struct __res_state *state,
+typedef int (*__libc_res_ninit)(struct __res_state *state);
+typedef int (*__libc___res_ninit)(struct __res_state *state);
+typedef void (*__libc_res_nclose)(struct __res_state *state);
+typedef void (*__libc___res_nclose)(struct __res_state *state);
+typedef int (*__libc_res_nquery)(struct __res_state *state,
                                 const char *dname,
                                 int class,
                                 int type,
                                 unsigned char *answer,
                                 int anslen);
-       int (*libc_res_nsearch)(struct __res_state *state,
-                               const char *dname,
-                               int class,
-                               int type,
-                               unsigned char *answer,
-                               int anslen);
-       int (*libc___res_nsearch)(struct __res_state *state,
+typedef int (*__libc___res_nquery)(struct __res_state *state,
+                                  const char *dname,
+                                  int class,
+                                  int type,
+                                  unsigned char *answer,
+                                  int anslen);
+typedef int (*__libc_res_nsearch)(struct __res_state *state,
                                  const char *dname,
                                  int class,
                                  int type,
                                  unsigned char *answer,
                                  int anslen);
+typedef int (*__libc___res_nsearch)(struct __res_state *state,
+                                   const char *dname,
+                                   int class,
+                                   int type,
+                                   unsigned char *answer,
+                                   int anslen);
+
+#define RWRAP_SYMBOL_ENTRY(i) \
+       union { \
+               __libc_##i f; \
+               void *obj; \
+       } _libc_##i
+
+struct rwrap_libc_symbols {
+       RWRAP_SYMBOL_ENTRY(res_ninit);
+       RWRAP_SYMBOL_ENTRY(__res_ninit);
+       RWRAP_SYMBOL_ENTRY(res_nclose);
+       RWRAP_SYMBOL_ENTRY(__res_nclose);
+       RWRAP_SYMBOL_ENTRY(res_nquery);
+       RWRAP_SYMBOL_ENTRY(__res_nquery);
+       RWRAP_SYMBOL_ENTRY(res_nsearch);
+       RWRAP_SYMBOL_ENTRY(__res_nsearch);
 };
+#undef RWRAP_SYMBOL_ENTRY
 
 struct rwrap {
-       void *libc_handle;
-       void *libresolv_handle;
+       struct {
+               void *handle;
+               struct rwrap_libc_symbols symbols;
+       } libc;
+
+       struct {
+               void *handle;
+               struct rwrap_libc_symbols symbols;
+       } libresolv;
 
        bool initialised;
        bool enabled;
 
        char *socket_dir;
-
-       struct rwrap_libc_fns fns;
 };
 
 static struct rwrap rwrap;
@@ -695,7 +1365,6 @@ enum rwrap_lib {
     RWRAP_LIBRESOLV
 };
 
-#ifndef NDEBUG
 static const char *rwrap_str_lib(enum rwrap_lib lib)
 {
        switch (lib) {
@@ -708,7 +1377,6 @@ static const char *rwrap_str_lib(enum rwrap_lib lib)
        /* Compiler would warn us about unhandled enum value if we get here */
        return "unknown";
 }
-#endif
 
 static void *rwrap_load_lib_handle(enum rwrap_lib lib)
 {
@@ -717,13 +1385,31 @@ static void *rwrap_load_lib_handle(enum rwrap_lib lib)
        int i;
 
 #ifdef RTLD_DEEPBIND
-       flags |= RTLD_DEEPBIND;
+       const char *env_preload = getenv("LD_PRELOAD");
+       const char *env_deepbind = getenv("RESOLV_WRAPPER_DISABLE_DEEPBIND");
+       bool enable_deepbind = true;
+
+       /* Don't do a deepbind if we run with libasan */
+       if (env_preload != NULL && strlen(env_preload) < 1024) {
+               const char *p = strstr(env_preload, "libasan.so");
+               if (p != NULL) {
+                       enable_deepbind = false;
+               }
+       }
+
+       if (env_deepbind != NULL && strlen(env_deepbind) >= 1) {
+               enable_deepbind = false;
+       }
+
+       if (enable_deepbind) {
+               flags |= RTLD_DEEPBIND;
+       }
 #endif
 
        switch (lib) {
        case RWRAP_LIBRESOLV:
 #ifdef HAVE_LIBRESOLV
-               handle = rwrap.libresolv_handle;
+               handle = rwrap.libresolv.handle;
                if (handle == NULL) {
                        for (i = 10; i >= 0; i--) {
                                char soname[256] = {0};
@@ -735,18 +1421,18 @@ static void *rwrap_load_lib_handle(enum rwrap_lib lib)
                                }
                        }
 
-                       rwrap.libresolv_handle = handle;
+                       rwrap.libresolv.handle = handle;
                }
                break;
 #endif
                /* FALL TROUGH */
        case RWRAP_LIBC:
-               handle = rwrap.libc_handle;
+               handle = rwrap.libc.handle;
 #ifdef LIBC_SO
                if (handle == NULL) {
                        handle = dlopen(LIBC_SO, flags);
 
-                       rwrap.libc_handle = handle;
+                       rwrap.libc.handle = handle;
                }
 #endif
                if (handle == NULL) {
@@ -760,14 +1446,14 @@ static void *rwrap_load_lib_handle(enum rwrap_lib lib)
                                }
                        }
 
-                       rwrap.libc_handle = handle;
+                       rwrap.libc.handle = handle;
                }
                break;
        }
 
        if (handle == NULL) {
 #ifdef RTLD_NEXT
-               handle = rwrap.libc_handle = rwrap.libresolv_handle = RTLD_NEXT;
+               handle = rwrap.libc.handle = rwrap.libresolv.handle = RTLD_NEXT;
 #else
                RWRAP_LOG(RWRAP_LOG_ERROR,
                          "Failed to dlopen library: %s\n",
@@ -779,7 +1465,7 @@ static void *rwrap_load_lib_handle(enum rwrap_lib lib)
        return handle;
 }
 
-static void *_rwrap_load_lib_function(enum rwrap_lib lib, const char *fn_name)
+static void *_rwrap_bind_symbol(enum rwrap_lib lib, const char *fn_name)
 {
        void *handle;
        void *func;
@@ -800,10 +1486,16 @@ static void *_rwrap_load_lib_function(enum rwrap_lib lib, const char *fn_name)
        return func;
 }
 
-#define rwrap_load_lib_function(lib, fn_name) \
-       if (rwrap.fns.libc_##fn_name == NULL) { \
-               *(void **) (&rwrap.fns.libc_##fn_name) = \
-                       _rwrap_load_lib_function(lib, #fn_name); \
+#define rwrap_bind_symbol_libc(sym_name) \
+       if (rwrap.libc.symbols._libc_##sym_name.obj == NULL) { \
+               rwrap.libc.symbols._libc_##sym_name.obj = \
+                       _rwrap_bind_symbol(RWRAP_LIBC, #sym_name); \
+       }
+
+#define rwrap_bind_symbol_libresolv(sym_name) \
+       if (rwrap.libresolv.symbols._libc_##sym_name.obj == NULL) { \
+               rwrap.libresolv.symbols._libc_##sym_name.obj = \
+                       _rwrap_bind_symbol(RWRAP_LIBRESOLV, #sym_name); \
        }
 
 /*
@@ -814,36 +1506,17 @@ static void *_rwrap_load_lib_function(enum rwrap_lib lib, const char *fn_name)
  * has probably something todo with with the linker.
  * So we need load each function at the point it is called the first time.
  */
-#if 0
-static int libc_res_init(void)
-{
-#if defined(HAVE_RES_INIT)
-       rwrap_load_lib_function(RWRAP_LIBRESOLV, res_init);
-
-       return rwrap.fns.libc_res_init();
-#elif defined(HAVE___RES_INIT)
-       rwrap_load_lib_function(RWRAP_LIBRESOLV, __res_init);
-
-       return rwrap.fns.libc___res_init();
-#endif
-}
-#endif
 
 static int libc_res_ninit(struct __res_state *state)
 {
-#if defined(HAVE_RES_NINIT)
+#if !defined(res_ninit) && defined(HAVE_RES_NINIT)
+       rwrap_bind_symbol_libresolv(res_ninit);
 
-#if defined(HAVE_RES_NINIT_IN_LIBRESOLV)
-       rwrap_load_lib_function(RWRAP_LIBRESOLV, res_ninit);
-#else /* HAVE_RES_NINIT_IN_LIBRESOLV */
-       rwrap_load_lib_function(RWRAP_LIBC, res_ninit);
-#endif /* HAVE_RES_NINIT_IN_LIBRESOLV */
-
-       return rwrap.fns.libc_res_ninit(state);
+       return rwrap.libresolv.symbols._libc_res_ninit.f(state);
 #elif defined(HAVE___RES_NINIT)
-       rwrap_load_lib_function(RWRAP_LIBC, __res_ninit);
+       rwrap_bind_symbol_libresolv(__res_ninit);
 
-       return rwrap.fns.libc___res_ninit(state);
+       return rwrap.libresolv.symbols._libc___res_ninit.f(state);
 #else
 #error "No res_ninit function"
 #endif
@@ -851,19 +1524,15 @@ static int libc_res_ninit(struct __res_state *state)
 
 static void libc_res_nclose(struct __res_state *state)
 {
-#if defined(HAVE_RES_NCLOSE)
-
-#if defined(HAVE_RES_NCLOSE_IN_LIBRESOLV)
-       rwrap_load_lib_function(RWRAP_LIBRESOLV, res_nclose);
-#else /* HAVE_RES_NCLOSE_IN_LIBRESOLV */
-       rwrap_load_lib_function(RWRAP_LIBC, res_nclose);
-#endif /* HAVE_RES_NCLOSE_IN_LIBRESOLV */
+#if !defined(res_close) && defined(HAVE_RES_NCLOSE)
+       rwrap_bind_symbol_libresolv(res_nclose);
 
-       rwrap.fns.libc_res_nclose(state);
+       rwrap.libresolv.symbols._libc_res_nclose.f(state);
+       return;
 #elif defined(HAVE___RES_NCLOSE)
-       rwrap_load_lib_function(RWRAP_LIBC, __res_nclose);
+       rwrap_bind_symbol_libresolv(__res_nclose);
 
-       rwrap.fns.libc___res_nclose(state);
+       rwrap.libresolv.symbols._libc___res_nclose.f(state);
 #else
 #error "No res_nclose function"
 #endif
@@ -876,24 +1545,24 @@ static int libc_res_nquery(struct __res_state *state,
                           unsigned char *answer,
                           int anslen)
 {
-#if defined(HAVE_RES_NQUERY)
-       rwrap_load_lib_function(RWRAP_LIBRESOLV, res_nquery);
-
-       return rwrap.fns.libc_res_nquery(state,
-                                        dname,
-                                        class,
-                                        type,
-                                        answer,
-                                        anslen);
+#if !defined(res_nquery) && defined(HAVE_RES_NQUERY)
+       rwrap_bind_symbol_libresolv(res_nquery);
+
+       return rwrap.libresolv.symbols._libc_res_nquery.f(state,
+                                                         dname,
+                                                         class,
+                                                         type,
+                                                         answer,
+                                                         anslen);
 #elif defined(HAVE___RES_NQUERY)
-       rwrap_load_lib_function(RWRAP_LIBRESOLV, __res_nquery);
-
-       return rwrap.fns.libc___res_nquery(state,
-                                          dname,
-                                          class,
-                                          type,
-                                          answer,
-                                          anslen);
+       rwrap_bind_symbol_libresolv(__res_nquery);
+
+       return rwrap.libresolv.symbols._libc___res_nquery.f(state,
+                                                           dname,
+                                                           class,
+                                                           type,
+                                                           answer,
+                                                           anslen);
 #else
 #error "No res_nquery function"
 #endif
@@ -906,24 +1575,24 @@ static int libc_res_nsearch(struct __res_state *state,
                            unsigned char *answer,
                            int anslen)
 {
-#if defined(HAVE_RES_NSEARCH)
-       rwrap_load_lib_function(RWRAP_LIBRESOLV, res_nsearch);
-
-       return rwrap.fns.libc_res_nsearch(state,
-                                         dname,
-                                         class,
-                                         type,
-                                         answer,
-                                         anslen);
+#if !defined(res_nsearch) && defined(HAVE_RES_NSEARCH)
+       rwrap_bind_symbol_libresolv(res_nsearch);
+
+       return rwrap.libresolv.symbols._libc_res_nsearch.f(state,
+                                                          dname,
+                                                          class,
+                                                          type,
+                                                          answer,
+                                                          anslen);
 #elif defined(HAVE___RES_NSEARCH)
-       rwrap_load_lib_function(RWRAP_LIBRESOLV, __res_nsearch);
-
-       return rwrap.fns.libc___res_nsearch(state,
-                                           dname,
-                                           class,
-                                           type,
-                                           answer,
-                                           anslen);
+       rwrap_bind_symbol_libresolv(__res_nsearch);
+
+       return rwrap.libresolv.symbols._libc___res_nsearch.f(state,
+                                                            dname,
+                                                            class,
+                                                            type,
+                                                            answer,
+                                                            anslen);
 #else
 #error "No res_nsearch function"
 #endif
@@ -976,14 +1645,13 @@ static int rwrap_parse_resolv_conf(struct __res_state *state,
 
                        ok = inet_pton(AF_INET, p, &a);
                        if (ok) {
-                               state->nsaddr_list[state->nscount] = (struct sockaddr_in) {
+                               state->nsaddr_list[nserv] = (struct sockaddr_in) {
                                        .sin_family = AF_INET,
                                        .sin_addr = a,
                                        .sin_port = htons(53),
                                        .sin_zero = { 0 },
                                };
 
-                               state->nscount++;
                                nserv++;
                        } else {
 #ifdef HAVE_RESOLV_IPV6_NSADDRS
@@ -1004,11 +1672,11 @@ static int rwrap_parse_resolv_conf(struct __res_state *state,
                                        sa6->sin6_flowinfo = 0;
                                        sa6->sin6_addr = a6;
 
-                                       state->_u._ext.nsaddrs[state->_u._ext.nscount] = sa6;
-                                       state->_u._ext.nssocks[state->_u._ext.nscount] = -1;
-                                       state->_u._ext.nsmap[state->_u._ext.nscount] = MAXNS + 1;
+                                       state->_u._ext.nsaddrs[nserv] = sa6;
+                                       state->_u._ext.nssocks[nserv] = -1;
+                                       state->_u._ext.nsmap[nserv] = MAXNS + 1;
 
-                                       state->_u._ext.nscount++;
+                                       state->_u._ext.nscount6++;
                                        nserv++;
                                } else {
                                        RWRAP_LOG(RWRAP_LOG_ERROR,
@@ -1031,6 +1699,13 @@ static int rwrap_parse_resolv_conf(struct __res_state *state,
                } /* TODO: match other keywords */
        }
 
+       /*
+        * note that state->_u._ext.nscount is left as 0,
+        * this matches glibc and allows resolv wrapper
+        * to work with most (maybe all) glibc versions.
+        */
+       state->nscount = nserv;
+
        if (ferror(fp)) {
                RWRAP_LOG(RWRAP_LOG_ERROR,
                          "Reading from %s failed",
@@ -1056,22 +1731,36 @@ static int rwrap_res_ninit(struct __res_state *state)
                const char *resolv_conf = getenv("RESOLV_WRAPPER_CONF");
 
                if (resolv_conf != NULL) {
+                       /* Delete name servers */
+#ifdef HAVE_RESOLV_IPV6_NSADDRS
                        uint16_t i;
 
-                       (void)i; /* maybe unused */
+                       for (i = 0; i < state->nscount; i++) {
+                               if (state->_u._ext.nssocks[i] != -1) {
+                                       close(state->_u._ext.nssocks[i]);
+                                       state->_u._ext.nssocks[i] = -1;
+                               }
+
+                               SAFE_FREE(state->_u._ext.nsaddrs[i]);
+                       }
+#endif
 
-                       /* Delete name servers */
                        state->nscount = 0;
                        memset(state->nsaddr_list, 0, sizeof(state->nsaddr_list));
 
-                       state->_u._ext.nscount = 0;
 #ifdef HAVE_RESOLV_IPV6_NSADDRS
-                       for (i = 0; i < state->_u._ext.nscount; i++) {
-                               free(state->_u._ext.nsaddrs[i]);
-                               state->_u._ext.nssocks[i] = 0;
+                       state->ipv6_unavail = false;
+                       state->_u._ext.nsinit = 0;
+                       state->_u._ext.nscount = 0;
+                       state->_u._ext.nscount6 = 0;
+                       for (i = 0; i < MAXNS; i++) {
+                               state->_u._ext.nsaddrs[i] = NULL;
+                               state->_u._ext.nssocks[i] = -1;
+                               state->_u._ext.nsmap[i] = MAXNS;
                        }
 #endif
 
+                       /* And parse the new name servers */
                        rc = rwrap_parse_resolv_conf(state, resolv_conf);
                }
        }
@@ -1079,7 +1768,7 @@ static int rwrap_res_ninit(struct __res_state *state)
        return rc;
 }
 
-#if defined(HAVE_RES_NINIT)
+#if !defined(res_ninit) && defined(HAVE_RES_NINIT)
 int res_ninit(struct __res_state *state)
 #elif defined(HAVE___RES_NINIT)
 int __res_ninit(struct __res_state *state)
@@ -1103,7 +1792,7 @@ static int rwrap_res_init(void)
        return rc;
 }
 
-#if defined(HAVE_RES_INIT)
+#if !defined(res_ninit) && defined(HAVE_RES_INIT)
 int res_init(void)
 #elif defined(HAVE___RES_INIT)
 int __res_init(void)
@@ -1118,26 +1807,16 @@ int __res_init(void)
 
 static void rwrap_res_nclose(struct __res_state *state)
 {
-#ifdef HAVE_RESOLV_IPV6_NSADDRS
-       int i;
-
-       if (state != NULL) {
-               for (i = 0; i < state->_u._ext.nscount; i++) {
-                       SAFE_FREE(state->_u._ext.nsaddrs[i]);
-                       state->_u._ext.nssocks[i] = 0;
-               }
-       }
-#endif
        libc_res_nclose(state);
 }
 
-#if defined(HAVE_RES_NCLOSE)
+#if !defined(res_nclose) && defined(HAVE_RES_NCLOSE)
 void res_nclose(struct __res_state *state)
 #elif defined(HAVE___RES_NCLOSE)
 void __res_nclose(struct __res_state *state)
 #endif
 {
-       libc_res_nclose(state);
+       rwrap_res_nclose(state);
 }
 
 /****************************************************************************
@@ -1204,7 +1883,7 @@ static int rwrap_res_nquery(struct __res_state *state,
        return rc;
 }
 
-#if defined(HAVE_RES_NQUERY)
+#if !defined(res_nquery) && defined(HAVE_RES_NQUERY)
 int res_nquery(struct __res_state *state,
               const char *dname,
               int class,
@@ -1250,7 +1929,7 @@ static int rwrap_res_query(const char *dname,
        return rc;
 }
 
-#if defined(HAVE_RES_QUERY)
+#if !defined(res_query) && defined(HAVE_RES_QUERY)
 int res_query(const char *dname,
              int class,
              int type,
@@ -1312,7 +1991,7 @@ static int rwrap_res_nsearch(struct __res_state *state,
        return rc;
 }
 
-#if defined(HAVE_RES_NSEARCH)
+#if !defined(res_nsearch) && defined(HAVE_RES_NSEARCH)
 int res_nsearch(struct __res_state *state,
                const char *dname,
                int class,
@@ -1332,7 +2011,7 @@ int __res_nsearch(struct __res_state *state,
 }
 
 /****************************************************************************
- *   RES_QUERY
+ *   RES_SEARCH
  ***************************************************************************/
 
 static int rwrap_res_search(const char *dname,
@@ -1358,7 +2037,7 @@ static int rwrap_res_search(const char *dname,
        return rc;
 }
 
-#if defined(HAVE_RES_SEARCH)
+#if !defined(res_search) && defined(HAVE_RES_SEARCH)
 int res_search(const char *dname,
               int class,
               int type,