/*
* Copyright (c) 2014 Andreas Schneider <asn@samba.org>
- * Copyright (c) 2014 Jakub Hrozek <jakub.hrozek@gmail.com>
+ * Copyright (c) 2014 Jakub Hrozek <jakub.hrozek@posteo.se>
*
* All rights reserved.
*
#define RWRAP_DEFAULT_FAKE_TTL 600
#endif /* RWRAP_DEFAULT_FAKE_TTL */
+#ifndef HAVE_NS_NAME_COMPRESS
+#define ns_name_compress dn_comp
+#endif
+
enum rwrap_dbglvl_e {
RWRAP_LOG_ERROR = 0,
RWRAP_LOG_WARN,
} \
} while(0);
+#define RWRAP_MAX_RECURSION 5
+
+/* 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
+
+struct rwrap_srv_rrdata {
+ uint16_t port;
+ uint16_t prio;
+ uint16_t weight;
+ char hostname[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_soa_rrdata soa_rec;
+ char cname_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_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_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;
+}
/* 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;
if (remaining < NS_HFIXEDSZ) {
RWRAP_LOG(RWRAP_LOG_ERROR, "Buffer too small!\n");
h->id = res_randomid(); /* random query ID */
h->qr = 1; /* response flag */
h->rd = 1; /* recursion desired */
- h->ra = 1; /* resursion available */
+ h->ra = 1; /* recursion available */
h->qdcount = htons(1); /* no. of questions */
- h->ancount = htons(answers); /* no. of answers */
+ h->ancount = htons(ancount); /* no. of answers */
+ h->arcount = htons(arcount); /* no. of add'tl records */
hb += NS_HFIXEDSZ; /* move past the header */
*header_blob = hb;
}
*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)
-{
- uint8_t *a = *answer_ptr;
- ssize_t written;
- size_t remaining;
-
- remaining = anslen;
-
- written = rwrap_fake_header(&a, remaining, rdata_size);
- if (written < 0) {
- return -1;
- }
- remaining -= written;
-
- written = rwrap_fake_question(question, type, &a, remaining);
- if (written < 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;
- }
- }
-
- *answer_ptr = a;
- return written;
-}
-
-static int rwrap_fake_a(const char *key,
- const char *value,
- 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;
- struct in_addr a_rec;
- int rc;
- int ok;
+ ssize_t resp_size;
- if (value == NULL) {
- RWRAP_LOG(RWRAP_LOG_ERROR, "Malformed record, no value!\n");
+ if (rr == NULL || rr->type != ns_t_a) {
+ RWRAP_LOG(RWRAP_LOG_ERROR,
+ "Malformed record, no or wrong value!\n");
return -1;
}
+ RWRAP_LOG(RWRAP_LOG_TRACE, "Adding A 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_a, sizeof(struct in_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.a_rec, sizeof(struct in_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_aaaa(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;
- if (value == NULL) {
- RWRAP_LOG(RWRAP_LOG_ERROR, "Malformed record, no value!\n");
+ if (rr == NULL || rr->type != ns_t_aaaa) {
+ RWRAP_LOG(RWRAP_LOG_ERROR,
+ "Malformed record, no or wrong value!\n");
return -1;
}
+ RWRAP_LOG(RWRAP_LOG_TRACE, "Adding AAAA RR");
- rc = rwrap_fake_common(ns_t_aaaa, key, sizeof(aaaa_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_INET6, value, &aaaa_rec);
- if (!ok) {
- RWRAP_LOG(RWRAP_LOG_ERROR,
- "Failed to convert [%s] to binary\n", value);
- return -1;
- }
- memcpy(a, &aaaa_rec, sizeof(struct in6_addr));
+ memcpy(a, &rr->rrdata.aaaa_rec, sizeof(struct in6_addr));
- return 0;
+ return resp_size;
}
-/*
- * 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
-
-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) {
+ if (rr == NULL || rr->type != ns_t_srv) {
RWRAP_LOG(RWRAP_LOG_ERROR,
- "Malformed SRV entry [%s]\n", value);
+ "Malformed record, no or wrong value!\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) {
}
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);
- }
- if (str_weight) {
- NS_PUT16(atoi(str_weight), a);
- } else {
- NS_PUT16(DFL_SRV_WEIGHT, a);
- }
- NS_PUT16(atoi(str_port), 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 0;
+ 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_soa(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;
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)
- {
+ if (rr == NULL || rr->type != ns_t_soa) {
RWRAP_LOG(RWRAP_LOG_ERROR,
- "Malformed SOA entry [%s]\n", value);
+ "Malformed record, no or wrong value!\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;
}
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 == NULL || rr->type != ns_t_cname) {
+ RWRAP_LOG(RWRAP_LOG_ERROR,
+ "Malformed record, no or wrong value!\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;
-}
-
-static int rwrap_fake_empty_query(const char *key,
- uint16_t type,
- uint8_t *answer,
- size_t anslen)
-{
- int rc;
-
- rc = rwrap_fake_common(type, key, 0, &answer, anslen);
- if (rc < 0) {
- return -1;
- }
-
- return 0;
+ return resp_size;
}
#define RESOLV_MATCH(line, name) \
#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_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;
+
+ 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);
NEXT_KEY(rec_type, key);
NEXT_KEY(key, value);
- 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"
continue;
}
+ q = value;
+ while(q[0] != '\n' && q[0] != '\0') {
+ q++;
+ }
+ q[0] = '\0';
+
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_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_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;
+ }
+ }
+
+ 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_srv:
+ case ns_t_soa:
+ case ns_t_cname:
+ return true;
+ }
+
+ return false;
+}
+
+static int rwrap_ancount(struct rwrap_fake_rr *rrs, int qtype)
+{
+ int i;
+ int ancount = 0;
+
+ /* 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;
+
+ 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_srv:
+ resp_data = rwrap_fake_srv(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;
+ 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_ERROR,
+ "Error searching for [%s]\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;
}
/*********************************************************
#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;
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};
}
}
- 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) {
}
}
- 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",
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;
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); \
}
/*
* 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)
#if defined(HAVE_RES_NINIT_IN_LIBRESOLV)
- rwrap_load_lib_function(RWRAP_LIBRESOLV, res_ninit);
+ rwrap_bind_symbol_libresolv(res_ninit);
+
+ return rwrap.libresolv.symbols._libc_res_ninit.f(state);
#else /* HAVE_RES_NINIT_IN_LIBRESOLV */
- rwrap_load_lib_function(RWRAP_LIBC, res_ninit);
+ rwrap_bind_symbol_libc(res_ninit);
+
+ return rwrap.libc.symbols._libc_res_ninit.f(state);
#endif /* HAVE_RES_NINIT_IN_LIBRESOLV */
- return rwrap.fns.libc_res_ninit(state);
#elif defined(HAVE___RES_NINIT)
- rwrap_load_lib_function(RWRAP_LIBC, __res_ninit);
+ rwrap_bind_symbol_libc(__res_ninit);
- return rwrap.fns.libc___res_ninit(state);
+ return rwrap.libc.symbols._libc___res_ninit.f(state);
#else
#error "No res_ninit function"
#endif
static void libc_res_nclose(struct __res_state *state)
{
-#if defined(HAVE_RES_NCLOSE)
+#if !defined(res_close) && defined(HAVE_RES_NCLOSE)
#if defined(HAVE_RES_NCLOSE_IN_LIBRESOLV)
- rwrap_load_lib_function(RWRAP_LIBRESOLV, res_nclose);
+ rwrap_bind_symbol_libresolv(res_nclose);
+
+ rwrap.libresolv.symbols._libc_res_nclose.f(state);
+ return;
#else /* HAVE_RES_NCLOSE_IN_LIBRESOLV */
- rwrap_load_lib_function(RWRAP_LIBC, res_nclose);
+ rwrap_bind_symbol_libc(res_nclose);
+
+ rwrap.libc.symbols._libc_res_nclose.f(state);
+ return;
#endif /* HAVE_RES_NCLOSE_IN_LIBRESOLV */
- rwrap.fns.libc_res_nclose(state);
#elif defined(HAVE___RES_NCLOSE)
- rwrap_load_lib_function(RWRAP_LIBC, __res_nclose);
+ rwrap_bind_symbol_libc(__res_nclose);
- rwrap.fns.libc___res_nclose(state);
+ rwrap.libc.symbols._libc___res_nclose.f(state);
#else
#error "No res_nclose function"
#endif
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
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
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;
+ SAFE_FREE(state->_u._ext.nsaddrs[i]);
}
#endif
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)
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)
{
#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]);
- 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);
}
/****************************************************************************
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,
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,
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,
}
/****************************************************************************
- * RES_QUERY
+ * RES_SEARCH
***************************************************************************/
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,
git.samba.org / resolv_wrapper.git / blobdiff