/*
- * Copyright (c) 2014 Andreas Schneider <asn@samba.org>
+ * Copyright (c) 2014-2018 Andreas Schneider <asn@samba.org>
+ * Copyright (c) 2014-2016 Jakub Hrozek <jakub.hrozek@posteo.se>
*
* All rights reserved.
*
#include "config.h"
+#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>
#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
#include <unistd.h>
+#include <ctype.h>
#include <resolv.h>
#define DESTRUCTOR_ATTRIBUTE
#endif /* HAVE_DESTRUCTOR_ATTRIBUTE */
+#ifndef RWRAP_DEFAULT_FAKE_TTL
+#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
-
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__)
const char *d;
unsigned int lvl = 0;
int pid = getpid();
+ const char *prefix = 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;
- }
- }
-}
-#endif /* NDEBUG RWRAP_LOG */
+ 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;
+ }
+
+ fprintf(stderr,
+ "%s(%d) - %s: %s\n",
+ prefix,
+ pid,
+ func,
+ buffer);
+}
+
+#ifndef SAFE_FREE
+#define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0)
+#endif
+
+#define NEXT_KEY(buf, key) do { \
+ (key) = (buf) ? strpbrk((buf), " \t") : NULL; \
+ if ((key) != NULL) { \
+ (key)[0] = '\0'; \
+ (key)++; \
+ } \
+ while ((key) != NULL \
+ && (isblank((int)(key)[0]))) { \
+ (key)++; \
+ } \
+} 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 [%s]\n", value);
+ 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 ancount, size_t arcount)
+{
+ union {
+ uint8_t *blob;
+ HEADER *header;
+ } h;
+
+ if (remaining < NS_HFIXEDSZ) {
+ RWRAP_LOG(RWRAP_LOG_ERROR, "Buffer too small!\n");
+ return -1;
+ }
+
+ h.blob = *header_blob;
+ memset(h.blob, 0, NS_HFIXEDSZ);
+
+ 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.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 */
+
+ /* move past the header */
+ *header_blob = h.blob += NS_HFIXEDSZ;
+
+ return NS_HFIXEDSZ;
+}
+
+static ssize_t rwrap_fake_question(const char *question,
+ uint16_t type,
+ uint8_t **question_ptr,
+ size_t remaining)
+{
+ uint8_t *qb = *question_ptr;
+ int n;
+
+ n = ns_name_compress(question, qb, remaining, NULL, NULL);
+ if (n < 0) {
+ RWRAP_LOG(RWRAP_LOG_ERROR,
+ "Failed to compress [%s]\n", question);
+ return -1;
+ }
+
+ qb += n;
+ remaining -= n;
+
+ if (remaining < 2 * sizeof(uint16_t)) {
+ RWRAP_LOG(RWRAP_LOG_ERROR, "Buffer too small!\n");
+ return -1;
+ }
+
+ NS_PUT16(type, qb);
+ NS_PUT16(ns_c_in, qb);
+
+ *question_ptr = qb;
+ return n + 2 * sizeof(uint16_t);
+}
+
+static ssize_t rwrap_fake_rdata_common(uint16_t type,
+ size_t rdata_size,
+ const char *key,
+ size_t remaining,
+ uint8_t **rdata_ptr)
+{
+ uint8_t *rd = *rdata_ptr;
+ ssize_t written = 0;
+
+ written = ns_name_compress(key, rd, remaining, NULL, NULL);
+ if (written < 0) {
+ RWRAP_LOG(RWRAP_LOG_ERROR,
+ "Failed to compress [%s]\n", key);
+ return -1;
+ }
+ rd += written;
+ remaining -= written;
+
+ if (remaining < 3 * sizeof(uint16_t) + sizeof(uint32_t)) {
+ RWRAP_LOG(RWRAP_LOG_ERROR, "Buffer too small\n");
+ return -1;
+ }
+
+ NS_PUT16(type, rd);
+ NS_PUT16(ns_c_in, rd);
+ NS_PUT32(RWRAP_DEFAULT_FAKE_TTL, rd);
+ NS_PUT16(rdata_size, rd);
+
+ if (remaining < rdata_size) {
+ RWRAP_LOG(RWRAP_LOG_ERROR, "Buffer too small\n");
+ return -1;
+ }
+
+ *rdata_ptr = rd;
+ return written + 3 * sizeof(uint16_t) + sizeof(uint32_t) + rdata_size;
+}
+
+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 resp_size;
+
+ if (rr->type != ns_t_a) {
+ RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
+ return -1;
+ }
+ RWRAP_LOG(RWRAP_LOG_TRACE, "Adding A RR");
+
+ resp_size = rwrap_fake_rdata_common(ns_t_a, sizeof(struct in_addr), rr->key,
+ anslen, &a);
+ if (resp_size < 0) {
+ return -1;
+ }
+
+ memcpy(a, &rr->rrdata.a_rec, sizeof(struct in_addr));
+
+ return resp_size;
+}
+
+static ssize_t rwrap_fake_aaaa(struct rwrap_fake_rr *rr,
+ uint8_t *answer,
+ size_t anslen)
+{
+ uint8_t *a = answer;
+ ssize_t resp_size;
+
+ if (rr->type != ns_t_aaaa) {
+ RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
+ return -1;
+ }
+ RWRAP_LOG(RWRAP_LOG_TRACE, "Adding AAAA RR");
+
+ resp_size = rwrap_fake_rdata_common(ns_t_aaaa, sizeof(struct in6_addr),
+ rr->key, anslen, &a);
+ if (resp_size < 0) {
+ return -1;
+ }
+
+ memcpy(a, &rr->rrdata.aaaa_rec, sizeof(struct in6_addr));
+
+ return resp_size;
+}
+
+static ssize_t rwrap_fake_ns(struct rwrap_fake_rr *rr,
+ uint8_t *answer,
+ size_t anslen)
+{
+ uint8_t *a = answer;
+ ssize_t resp_size = 0;
+ size_t rdata_size;
+ unsigned char hostname_compressed[MAXDNAME];
+ ssize_t compressed_len;
+
+ if (rr->type != ns_t_ns) {
+ RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
+ return -1;
+ }
+ RWRAP_LOG(RWRAP_LOG_TRACE, "Adding NS RR");
+
+ /* 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;
+ }
+
+ /* 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, hostname_compressed, compressed_len);
+
+ return resp_size;
+}
+
+static ssize_t rwrap_fake_srv(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 hostname_compressed[MAXDNAME];
+ ssize_t compressed_len;
+
+ 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(rr->rrdata.srv_rec.hostname,
+ hostname_compressed, MAXDNAME,
+ NULL, NULL);
+ if (compressed_len < 0) {
+ return -1;
+ }
+ rdata_size += compressed_len;
+
+ resp_size = rwrap_fake_rdata_common(ns_t_srv, rdata_size,
+ rr->key, anslen, &a);
+ if (resp_size < 0) {
+ return -1;
+ }
+
+ 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;
+ }
+ 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(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 ssize_t rwrap_fake_txt(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 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;
+
+ 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(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(rr->rrdata.soa_rec.mailbox,
+ mailbox_compressed,
+ MAXDNAME, NULL, NULL);
+ if (compressed_mb_len < 0) {
+ return -1;
+ }
+ rdata_size += compressed_mb_len;
+
+ resp_size = rwrap_fake_rdata_common(ns_t_soa, rdata_size,
+ rr->key, anslen, &a);
+ if (resp_size < 0) {
+ return -1;
+ }
+
+ memcpy(a, nameser_compressed, compressed_ns_len);
+ a += compressed_ns_len;
+ memcpy(a, mailbox_compressed, compressed_mb_len);
+ a += compressed_mb_len;
+ 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 resp_size;
+}
+
+static ssize_t rwrap_fake_cname(struct rwrap_fake_rr *rr,
+ uint8_t *answer,
+ size_t anslen)
+{
+ uint8_t *a = answer;
+ ssize_t resp_size;
+ unsigned char hostname_compressed[MAXDNAME];
+ ssize_t rdata_size;
+
+ 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(rr->rrdata.cname_rec,
+ hostname_compressed, MAXDNAME,
+ NULL, NULL);
+ if (rdata_size < 0) {
+ return -1;
+ }
+
+ 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 resp_size;
+}
+
+static ssize_t rwrap_fake_ptr(struct rwrap_fake_rr *rr,
+ uint8_t *answer,
+ size_t anslen)
+{
+ uint8_t *a = answer;
+ ssize_t rdata_size;
+ ssize_t resp_size;
+ unsigned char hostname_compressed[MAXDNAME];
+
+ if (rr->type != ns_t_ptr) {
+ RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
+ return -1;
+ }
+ RWRAP_LOG(RWRAP_LOG_TRACE, "Adding PTR RR");
+
+ /* 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) \
+ (strncmp(line, name, sizeof(name) - 1) == 0 && \
+ (line[sizeof(name) - 1] == ' ' || \
+ line[sizeof(name) - 1] == '\t'))
+
+#define TYPE_MATCH(type, ns_type, rec_type, str_type, key, query) \
+ ((type) == (ns_type) && \
+ (strncmp((rec_type), (str_type), sizeof(str_type)) == 0) && \
+ (strcasecmp(key, query)) == 0)
+
+
+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];
+ 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 for %s:%d\n", hostfile,
+ query, type);
+
+ fp = fopen(hostfile, "r");
+ if (fp == NULL) {
+ RWRAP_LOG(RWRAP_LOG_WARN,
+ "Opening %s failed: %s",
+ hostfile, strerror(errno));
+ return -1;
+ }
+
+ while (fgets(buf, sizeof(buf), fp) != NULL) {
+ char *rec_type;
+ char *q;
+
+ rec_type = buf;
+ key = value = NULL;
+
+ 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 (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_create_fake_a_rr(key, value, rr);
+ break;
+ } else if (TYPE_MATCH(type, ns_t_aaaa,
+ rec_type, "AAAA", key, query)) {
+ 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_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_create_fake_soa_rr(key, value, rr);
+ break;
+ } else if (TYPE_MATCH(type, ns_t_cname,
+ 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_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,
+ "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_name);
+ break;
+ default:
+ RWRAP_LOG(RWRAP_LOG_TRACE,
+ "Successfully faked answer for [%s]\n",
+ query_name);
+ break;
+ }
+
+ free(query_name);
+ return resp_size;
+}
+
+/*********************************************************
+ * RWRAP LOADING LIBC FUNCTIONS
+ *********************************************************/
+
+#include <dlfcn.h>
+
+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);
+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 {
+ 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;
+};
+
+static struct rwrap rwrap;
+
+enum rwrap_lib {
+ RWRAP_LIBC,
+ RWRAP_LIBRESOLV
+};
+
+static const char *rwrap_str_lib(enum rwrap_lib lib)
+{
+ switch (lib) {
+ case RWRAP_LIBC:
+ return "libc";
+ case RWRAP_LIBRESOLV:
+ return "libresolv";
+ }
+
+ /* Compiler would warn us about unhandled enum value if we get here */
+ return "unknown";
+}
+
+static void *rwrap_load_lib_handle(enum rwrap_lib lib)
+{
+ int flags = RTLD_LAZY;
+ void *handle = NULL;
+ int i;
+
+#ifdef 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;
+ if (handle == NULL) {
+ for (i = 10; i >= 0; i--) {
+ char soname[256] = {0};
+
+ snprintf(soname, sizeof(soname), "libresolv.so.%d", i);
+ handle = dlopen(soname, flags);
+ if (handle != NULL) {
+ break;
+ }
+ }
+
+ rwrap.libresolv.handle = handle;
+ }
+ break;
+#endif
+ /* FALL TROUGH */
+ case RWRAP_LIBC:
+ handle = rwrap.libc.handle;
+#ifdef LIBC_SO
+ if (handle == NULL) {
+ handle = dlopen(LIBC_SO, flags);
+
+ rwrap.libc.handle = handle;
+ }
+#endif
+ if (handle == NULL) {
+ for (i = 10; i >= 0; i--) {
+ char soname[256] = {0};
+
+ snprintf(soname, sizeof(soname), "libc.so.%d", i);
+ handle = dlopen(soname, flags);
+ if (handle != NULL) {
+ break;
+ }
+ }
+
+ rwrap.libc.handle = handle;
+ }
+ break;
+ }
+
+ if (handle == NULL) {
+#ifdef RTLD_NEXT
+ handle = rwrap.libc.handle = rwrap.libresolv.handle = RTLD_NEXT;
+#else
+ RWRAP_LOG(RWRAP_LOG_ERROR,
+ "Failed to dlopen library: %s\n",
+ dlerror());
+ exit(-1);
+#endif
+ }
+
+ return handle;
+}
+
+static void *_rwrap_bind_symbol(enum rwrap_lib lib, const char *fn_name)
+{
+ void *handle;
+ void *func;
+
+ handle = rwrap_load_lib_handle(lib);
+
+ func = dlsym(handle, fn_name);
+ if (func == NULL) {
+ RWRAP_LOG(RWRAP_LOG_ERROR,
+ "Failed to find %s: %s\n",
+ fn_name, dlerror());
+ exit(-1);
+ }
+
+ RWRAP_LOG(RWRAP_LOG_TRACE,
+ "Loaded %s from %s",
+ fn_name, rwrap_str_lib(lib));
+ return func;
+}
+
+#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); \
+ }
+
+/*
+ * IMPORTANT
+ *
+ * Functions especially from libc need to be loaded individually, you can't load
+ * all at once or gdb will segfault at startup. The same applies to valgrind and
+ * has probably something todo with with the linker.
+ * So we need load each function at the point it is called the first time.
+ */
+
+static int libc_res_ninit(struct __res_state *state)
+{
+#if !defined(res_ninit) && defined(HAVE_RES_NINIT)
+ rwrap_bind_symbol_libresolv(res_ninit);
+
+ return rwrap.libresolv.symbols._libc_res_ninit.f(state);
+#elif defined(HAVE___RES_NINIT)
+ rwrap_bind_symbol_libresolv(__res_ninit);
+
+ return rwrap.libresolv.symbols._libc___res_ninit.f(state);
+#else
+#error "No res_ninit function"
+#endif
+}
+
+static void libc_res_nclose(struct __res_state *state)
+{
+#if !defined(res_close) && defined(HAVE_RES_NCLOSE)
+ rwrap_bind_symbol_libresolv(res_nclose);
+
+ rwrap.libresolv.symbols._libc_res_nclose.f(state);
+ return;
+#elif defined(HAVE___RES_NCLOSE)
+ rwrap_bind_symbol_libresolv(__res_nclose);
+
+ rwrap.libresolv.symbols._libc___res_nclose.f(state);
+#else
+#error "No res_nclose function"
+#endif
+}
+
+static int libc_res_nquery(struct __res_state *state,
+ const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int 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_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
+}
+
+static int libc_res_nsearch(struct __res_state *state,
+ const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int 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_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
+}
+
+/****************************************************************************
+ * RES_HELPER
+ ***************************************************************************/
+
+static int rwrap_parse_resolv_conf(struct __res_state *state,
+ const char *resolv_conf)
+{
+ FILE *fp;
+ char buf[BUFSIZ];
+ int nserv = 0;
+
+ fp = fopen(resolv_conf, "r");
+ if (fp == NULL) {
+ RWRAP_LOG(RWRAP_LOG_ERROR,
+ "Opening %s failed: %s",
+ resolv_conf, strerror(errno));
+ return -1;
+ }
+
+ while(fgets(buf, sizeof(buf), fp) != NULL) {
+ char *p;
+
+ /* Ignore comments */
+ if (buf[0] == '#' || buf[0] == ';') {
+ continue;
+ }
+
+ if (RESOLV_MATCH(buf, "nameserver") && nserv < MAXNS) {
+ struct in_addr a;
+ char *q;
+ int ok;
+
+ p = buf + strlen("nameserver");
+
+ /* Skip spaces and tabs */
+ while(isblank((int)p[0])) {
+ p++;
+ }
+
+ q = p;
+ while(q[0] != '\n' && q[0] != '\0') {
+ q++;
+ }
+ q[0] = '\0';
+
+ ok = inet_pton(AF_INET, p, &a);
+ if (ok) {
+ state->nsaddr_list[state->nscount] = (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
+ /* IPv6 */
+ struct in6_addr a6;
+ ok = inet_pton(AF_INET6, p, &a6);
+ if (ok) {
+ struct sockaddr_in6 *sa6;
+
+ sa6 = malloc(sizeof(*sa6));
+ if (sa6 == NULL) {
+ fclose(fp);
+ return -1;
+ }
+
+ sa6->sin6_family = AF_INET6;
+ sa6->sin6_port = htons(53);
+ 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.nscount++;
+ nserv++;
+ } else {
+ RWRAP_LOG(RWRAP_LOG_ERROR,
+ "Malformed DNS server");
+ continue;
+ }
+#else /* !HAVE_RESOLV_IPV6_NSADDRS */
+ /*
+ * BSD uses an opaque structure to store the
+ * IPv6 addresses. So we can not simply store
+ * these addresses the same way as above.
+ */
+ RWRAP_LOG(RWRAP_LOG_WARN,
+ "resolve_wrapper does not support "
+ "IPv6 on this platform");
+ continue;
+#endif
+ }
+ continue;
+ } /* TODO: match other keywords */
+ }
+
+ if (ferror(fp)) {
+ RWRAP_LOG(RWRAP_LOG_ERROR,
+ "Reading from %s failed",
+ resolv_conf);
+ fclose(fp);
+ return -1;
+ }
+
+ fclose(fp);
+ return 0;
+}
+
+/****************************************************************************
+ * RES_NINIT
+ ***************************************************************************/
+
+static int rwrap_res_ninit(struct __res_state *state)
+{
+ int rc;
+
+ rc = libc_res_ninit(state);
+ if (rc == 0) {
+ const char *resolv_conf = getenv("RESOLV_WRAPPER_CONF");
+
+ if (resolv_conf != NULL) {
+ uint16_t i;
+
+ (void)i; /* maybe unused */
+
+ /* Delete name servers */
+ state->nscount = 0;
+ memset(state->nsaddr_list, 0, sizeof(state->nsaddr_list));
+
+#ifdef HAVE_RESOLV_IPV6_NSADDRS
+ state->_u._ext.nscount = 0;
+ for (i = 0; i < state->_u._ext.nscount; i++) {
+ SAFE_FREE(state->_u._ext.nsaddrs[i]);
+ }
+#endif
+
+ rc = rwrap_parse_resolv_conf(state, resolv_conf);
+ }
+ }
+
+ return rc;
+}
+
+#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)
+#endif
+{
+ return rwrap_res_ninit(state);
+}
+
+/****************************************************************************
+ * RES_INIT
+ ***************************************************************************/
+
+static struct __res_state rwrap_res_state;
+
+static int rwrap_res_init(void)
+{
+ int rc;
+
+ rc = rwrap_res_ninit(&rwrap_res_state);
+
+ return rc;
+}
+
+#if !defined(res_ninit) && defined(HAVE_RES_INIT)
+int res_init(void)
+#elif defined(HAVE___RES_INIT)
+int __res_init(void)
+#endif
+{
+ return rwrap_res_init();
+}
+
+/****************************************************************************
+ * RES_NCLOSE
+ ***************************************************************************/
+
+static void rwrap_res_nclose(struct __res_state *state)
+{
+#ifdef HAVE_RESOLV_IPV6_NSADDRS
+ int i;
+#endif
+
+ libc_res_nclose(state);
+
+#ifdef HAVE_RESOLV_IPV6_NSADDRS
+ if (state != NULL) {
+ for (i = 0; i < state->_u._ext.nscount; i++) {
+ SAFE_FREE(state->_u._ext.nsaddrs[i]);
+ }
+ }
+#endif
+}
+
+#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
+{
+ rwrap_res_nclose(state);
+}
+
+/****************************************************************************
+ * RES_CLOSE
+ ***************************************************************************/
+
+static void rwrap_res_close(void)
+{
+ rwrap_res_nclose(&rwrap_res_state);
+}
+
+#if defined(HAVE_RES_CLOSE)
+void res_close(void)
+#elif defined(HAVE___RES_CLOSE)
+void __res_close(void)
+#endif
+{
+ rwrap_res_close();
+}
+
+/****************************************************************************
+ * RES_NQUERY
+ ***************************************************************************/
+
+static int rwrap_res_nquery(struct __res_state *state,
+ const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+{
+ int rc;
+ const char *fake_hosts;
+#ifndef NDEBUG
+ int i;
+#endif
+
+ RWRAP_LOG(RWRAP_LOG_TRACE,
+ "Resolve the domain name [%s] - class=%d, type=%d",
+ dname, class, type);
+#ifndef NDEBUG
+ for (i = 0; i < state->nscount; i++) {
+ char ip[INET6_ADDRSTRLEN];
+
+ inet_ntop(AF_INET, &state->nsaddr_list[i].sin_addr, ip, sizeof(ip));
+ RWRAP_LOG(RWRAP_LOG_TRACE,
+ " nameserver: %s",
+ ip);
+ }
+#endif
+
+ fake_hosts = getenv("RESOLV_WRAPPER_HOSTS");
+ if (fake_hosts != NULL) {
+ rc = rwrap_res_fake_hosts(fake_hosts, dname, type, answer, anslen);
+ } else {
+ rc = libc_res_nquery(state, dname, class, type, answer, anslen);
+ }
+
+
+ RWRAP_LOG(RWRAP_LOG_TRACE,
+ "The returned response length is: %d",
+ rc);
+
+ return rc;
+}
+
+#if !defined(res_nquery) && defined(HAVE_RES_NQUERY)
+int res_nquery(struct __res_state *state,
+ const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+#elif defined(HAVE___RES_NQUERY)
+int __res_nquery(struct __res_state *state,
+ const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+#endif
+{
+ return rwrap_res_nquery(state, dname, class, type, answer, anslen);
+}
+
+/****************************************************************************
+ * RES_QUERY
+ ***************************************************************************/
+
+static int rwrap_res_query(const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+{
+ int rc;
+
+ rc = rwrap_res_ninit(&rwrap_res_state);
+ if (rc != 0) {
+ return rc;
+ }
+
+ rc = rwrap_res_nquery(&rwrap_res_state,
+ dname,
+ class,
+ type,
+ answer,
+ anslen);
+
+ return rc;
+}
+
+#if !defined(res_query) && defined(HAVE_RES_QUERY)
+int res_query(const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+#elif defined(HAVE___RES_QUERY)
+int __res_query(const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+#endif
+{
+ return rwrap_res_query(dname, class, type, answer, anslen);
+}
+
+/****************************************************************************
+ * RES_NSEARCH
+ ***************************************************************************/
+
+static int rwrap_res_nsearch(struct __res_state *state,
+ const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+{
+ int rc;
+ const char *fake_hosts;
+#ifndef NDEBUG
+ int i;
+#endif
+
+ RWRAP_LOG(RWRAP_LOG_TRACE,
+ "Resolve the domain name [%s] - class=%d, type=%d",
+ dname, class, type);
+#ifndef NDEBUG
+ for (i = 0; i < state->nscount; i++) {
+ char ip[INET6_ADDRSTRLEN];
+
+ inet_ntop(AF_INET, &state->nsaddr_list[i].sin_addr, ip, sizeof(ip));
+ RWRAP_LOG(RWRAP_LOG_TRACE,
+ " nameserver: %s",
+ ip);
+ }
+#endif
+
+ fake_hosts = getenv("RESOLV_WRAPPER_HOSTS");
+ if (fake_hosts != NULL) {
+ rc = rwrap_res_fake_hosts(fake_hosts, dname, type, answer, anslen);
+ } else {
+ rc = libc_res_nsearch(state, dname, class, type, answer, anslen);
+ }
+
+ RWRAP_LOG(RWRAP_LOG_TRACE,
+ "The returned response length is: %d",
+ rc);
+
+ return rc;
+}
+
+#if !defined(res_nsearch) && defined(HAVE_RES_NSEARCH)
+int res_nsearch(struct __res_state *state,
+ const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+#elif defined(HAVE___RES_NSEARCH)
+int __res_nsearch(struct __res_state *state,
+ const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+#endif
+{
+ return rwrap_res_nsearch(state, dname, class, type, answer, anslen);
+}
+
+/****************************************************************************
+ * RES_SEARCH
+ ***************************************************************************/
+
+static int rwrap_res_search(const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+{
+ int rc;
+
+ rc = rwrap_res_ninit(&rwrap_res_state);
+ if (rc != 0) {
+ return rc;
+ }
+
+ rc = rwrap_res_nsearch(&rwrap_res_state,
+ dname,
+ class,
+ type,
+ answer,
+ anslen);
+
+ return rc;
+}
+
+#if !defined(res_search) && defined(HAVE_RES_SEARCH)
+int res_search(const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+#elif defined(HAVE___RES_SEARCH)
+int __res_search(const char *dname,
+ int class,
+ int type,
+ unsigned char *answer,
+ int anslen)
+#endif
+{
+ return rwrap_res_search(dname, class, type, answer, anslen);
+}
git.samba.org / resolv_wrapper.git / blobdiff