*
* Resolver library with GLib integration
*
- * Copyright (C) 2009-2010 Intel Corporation. All rights reserved.
+ * Copyright (C) 2009-2012 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
#include <netdb.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
+#include <net/if.h>
#include "gresolv.h"
};
struct _GResolv {
- gint ref_count;
+ int ref_count;
+
+ int result_family;
guint next_lookup_id;
GQueue *lookup_queue;
gpointer debug_data;
};
-static void sort_and_return_results(struct resolv_lookup *lookup);
-static void rfc3484_sort_results(struct resolv_lookup *lookup);
-
static inline void debug(GResolv *resolv, const char *format, ...)
{
char str[256];
static void destroy_lookup(struct resolv_lookup *lookup)
{
- if (lookup->ipv4_query) {
+ if (lookup->ipv4_query != NULL) {
+ g_queue_remove(lookup->resolv->query_queue,
+ lookup->ipv4_query);
destroy_query(lookup->ipv4_query);
- g_queue_remove(lookup->resolv->query_queue, lookup->ipv4_query);
}
- if (lookup->ipv6_query) {
+
+ if (lookup->ipv6_query != NULL) {
+ g_queue_remove(lookup->resolv->query_queue,
+ lookup->ipv6_query);
destroy_query(lookup->ipv6_query);
- g_queue_remove(lookup->resolv->query_queue, lookup->ipv4_query);
}
+
g_free(lookup->results);
g_free(lookup);
}
+static void find_srcaddr(struct sort_result *res)
+{
+ socklen_t sl = sizeof(res->src);
+ int fd;
+
+ fd = socket(res->dst.sa.sa_family, SOCK_DGRAM | SOCK_CLOEXEC,
+ IPPROTO_IP);
+ if (fd < 0)
+ return;
+
+ if (connect(fd, &res->dst.sa, sizeof(res->dst)) < 0) {
+ close(fd);
+ return;
+ }
+
+ if (getsockname(fd, &res->src.sa, &sl) < 0) {
+ close(fd);
+ return;
+ }
+
+ res->reachable = TRUE;
+ close(fd);
+}
+
+struct gai_table
+{
+ unsigned char addr[NS_IN6ADDRSZ];
+ int mask;
+ int value;
+};
+
+static const struct gai_table gai_labels[] = {
+ {
+ .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
+ .mask = 128,
+ .value = 0,
+ }, {
+ .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 16,
+ .value = 2,
+ }, {
+ .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 96,
+ .value = 3,
+ }, {
+ .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 96,
+ .value = 4,
+ }, {
+ /* Variations from RFC 3484, matching glibc behaviour */
+ .addr = { 0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 10,
+ .value = 5,
+ }, {
+ .addr = { 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 7,
+ .value = 6,
+ }, {
+ .addr = { 0x20, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 32,
+ .value = 7,
+ }, {
+ /* catch-all */
+ .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 0,
+ .value = 1,
+ }
+};
+
+static const struct gai_table gai_precedences[] = {
+ {
+ .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
+ .mask = 128,
+ .value = 50,
+ }, {
+ .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 16,
+ .value = 30,
+ }, {
+ .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 96,
+ .value = 20,
+ }, {
+ .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 96,
+ .value = 10,
+ }, {
+ .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+ .mask = 0,
+ .value = 40,
+ }
+};
+
+static unsigned char v4mapped[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 };
+
+static gboolean mask_compare(const unsigned char *one,
+ const unsigned char *two, int mask)
+{
+ if (mask > 8) {
+ if (memcmp(one, two, mask / 8))
+ return FALSE;
+ one += mask / 8;
+ two += mask / 8;
+ mask %= 8;
+ }
+
+ if (mask && ((*one ^ *two) >> (8 - mask)))
+ return FALSE;
+
+ return TRUE;
+}
+
+static int match_gai_table(struct sockaddr *sa, const struct gai_table *tbl)
+{
+ struct sockaddr_in *sin = (void *)sa;
+ struct sockaddr_in6 *sin6 = (void *)sa;
+ void *addr;
+
+ if (sa->sa_family == AF_INET) {
+ addr = v4mapped;
+ memcpy(v4mapped+12, &sin->sin_addr, NS_INADDRSZ);
+ } else
+ addr = &sin6->sin6_addr;
+
+ while (1) {
+ if (mask_compare(addr, tbl->addr, tbl->mask))
+ return tbl->value;
+ tbl++;
+ }
+}
+
+#define DQUAD(_a,_b,_c,_d) ( ((_a)<<24) | ((_b)<<16) | ((_c)<<8) | (_d) )
+#define V4MATCH(addr, a,b,c,d, m) ( ((addr) ^ DQUAD(a,b,c,d)) >> (32 - (m)) )
+
+#define RFC3484_SCOPE_LINK 2
+#define RFC3484_SCOPE_SITE 5
+#define RFC3484_SCOPE_GLOBAL 14
+
+static int addr_scope(struct sockaddr *sa)
+{
+ if (sa->sa_family == AF_INET) {
+ struct sockaddr_in *sin = (void *)sa;
+ guint32 addr = ntohl(sin->sin_addr.s_addr);
+
+ if (V4MATCH(addr, 169,254,0,0, 16) ||
+ V4MATCH(addr, 127,0,0,0, 8))
+ return RFC3484_SCOPE_LINK;
+
+ /* Site-local */
+ if (V4MATCH(addr, 10,0,0,0, 8) ||
+ V4MATCH(addr, 172,16,0,0, 12) ||
+ V4MATCH(addr, 192,168,0,0, 16))
+ return RFC3484_SCOPE_SITE;
+
+ /* Global */
+ return RFC3484_SCOPE_GLOBAL;
+ } else {
+ struct sockaddr_in6 *sin6 = (void *)sa;
+
+ /* Multicast addresses have a 4-bit scope field */
+ if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
+ return sin6->sin6_addr.s6_addr[1] & 0xf;
+
+ if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) ||
+ IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
+ return RFC3484_SCOPE_LINK;
+
+ if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
+ return RFC3484_SCOPE_SITE;
+
+ return RFC3484_SCOPE_GLOBAL;
+ }
+}
+
+static int rfc3484_compare(const void *__one, const void *__two)
+{
+ const struct sort_result *one = __one;
+ const struct sort_result *two = __two;
+
+ /* Rule 1: Avoid unusable destinations */
+ if (one->reachable && !two->reachable)
+ return -1;
+ else if (two->reachable && !one->reachable)
+ return 1;
+
+ /* Rule 2: Prefer matching scope */
+ if (one->dst_scope == one->src_scope &&
+ two->dst_scope != two->src_scope)
+ return -1;
+ else if (two->dst_scope == two->src_scope &&
+ one->dst_scope != one->src_scope)
+ return 1;
+
+ /* Rule 3: Avoid deprecated addresses */
+
+ /* Rule 4: Prefer home addresses */
+
+ /* Rule 5: Prefer matching label */
+ if (one->dst_label == one->src_label &&
+ two->dst_label != two->src_label)
+ return -1;
+ else if (two->dst_label == two->src_label &&
+ one->dst_label != one->src_label)
+ return 1;
+
+ /* Rule 6: Prefer higher precedence */
+ if (one->precedence > two->precedence)
+ return -1;
+ else if (two->precedence > one->precedence)
+ return 1;
+
+ /* Rule 7: Prefer native transport */
+
+ /* Rule 8: Prefer smaller scope */
+ if (one->dst_scope != two->dst_scope)
+ return one->dst_scope - two->dst_scope;
+
+ /* Rule 9: Use longest matching prefix */
+ if (one->dst.sa.sa_family == AF_INET) {
+ /*
+ * Rule 9 is meaningless and counterproductive for Legacy IP
+ * unless perhaps we can tell that it's actually on the local
+ * subnet. But we don't (yet) have local interface config
+ * information, so do nothing here for Legacy IP for now.
+ */
+ } else {
+ int i;
+
+ for (i = 0; i < 4; i++) {
+ guint32 cmp_one, cmp_two;
+
+ cmp_one = one->src.sin6.sin6_addr.s6_addr32[i] ^
+ one->dst.sin6.sin6_addr.s6_addr32[i];
+ cmp_two = two->src.sin6.sin6_addr.s6_addr32[i] ^
+ two->dst.sin6.sin6_addr.s6_addr32[i];
+
+ if (!cmp_two && !cmp_one)
+ continue;
+
+ if (cmp_one && !cmp_two)
+ return 1;
+ if (cmp_two && !cmp_one)
+ return -1;
+
+ /* g_bit_storage() is effectively fls() */
+ cmp_one = g_bit_storage(ntohl(cmp_one));
+ cmp_two = g_bit_storage(ntohl(cmp_two));
+
+ if (cmp_one == cmp_two)
+ break;
+
+ return cmp_one - cmp_two;
+ }
+ }
+
+
+ /* Rule 10: Otherwise, leave the order unchanged */
+ if (one < two)
+ return -1;
+ else
+ return 1;
+}
+
+static void rfc3484_sort_results(struct resolv_lookup *lookup)
+{
+ int i;
+
+ for (i = 0; i < lookup->nr_results; i++) {
+ struct sort_result *res = &lookup->results[i];
+ find_srcaddr(res);
+ res->precedence = match_gai_table(&res->dst.sa,
+ gai_precedences);
+ res->dst_label = match_gai_table(&res->dst.sa, gai_labels);
+ res->src_label = match_gai_table(&res->src.sa, gai_labels);
+ res->dst_scope = addr_scope(&res->dst.sa);
+ res->src_scope = addr_scope(&res->src.sa);
+ }
+
+ qsort(lookup->results, lookup->nr_results,
+ sizeof(struct sort_result), rfc3484_compare);
+}
+
+static void sort_and_return_results(struct resolv_lookup *lookup)
+{
+ char buf[INET6_ADDRSTRLEN + 1];
+ GResolvResultStatus status;
+ char **results = g_try_new0(char *, lookup->nr_results + 1);
+ int i, n = 0;
+
+ if (!results)
+ return;
+
+ memset(buf, 0, INET6_ADDRSTRLEN + 1);
+
+ rfc3484_sort_results(lookup);
+
+ for (i = 0; i < lookup->nr_results; i++) {
+ if (lookup->results[i].dst.sa.sa_family == AF_INET) {
+ if (inet_ntop(AF_INET,
+ &lookup->results[i].dst.sin.sin_addr,
+ buf, sizeof(buf) - 1) == NULL)
+ continue;
+ } else if (lookup->results[i].dst.sa.sa_family == AF_INET6) {
+ if (inet_ntop(AF_INET6,
+ &lookup->results[i].dst.sin6.sin6_addr,
+ buf, sizeof(buf) - 1) == NULL)
+ continue;
+ } else
+ continue;
+
+ results[n++] = strdup(buf);
+ }
+
+ results[n++] = NULL;
+
+ status = lookup->ipv4_status;
+
+ if (status == G_RESOLV_RESULT_STATUS_SUCCESS)
+ status = lookup->ipv6_status;
+
+ lookup->result_func(status, results, lookup->result_data);
+
+ g_strfreev(results);
+ g_queue_remove(lookup->resolv->lookup_queue, lookup);
+ destroy_lookup(lookup);
+}
+
static gboolean query_timeout(gpointer user_data)
{
struct resolv_query *query = user_data;
lookup->ipv6_status = G_RESOLV_RESULT_STATUS_NO_RESPONSE;
lookup->ipv6_query = NULL;
}
- if (!lookup->ipv4_query && !lookup->ipv4_query)
+
+ if (lookup->ipv4_query == NULL && lookup->ipv4_query == NULL)
sort_and_return_results(lookup);
destroy_query(query);
sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
sent = send(sk, buf, len, 0);
+ if (sent < 0)
+ continue;
}
return 0;
return 0;
}
-static void add_result(struct resolv_lookup *lookup, int family, const void *data)
+static void add_result(struct resolv_lookup *lookup, int family,
+ const void *data)
{
int n = lookup->nr_results++;
lookup->results = g_realloc(lookup->results,
- sizeof(struct sort_result) * (n+1));
+ sizeof(struct sort_result) * (n + 1));
memset(&lookup->results[n], 0, sizeof(struct sort_result));
lookup->results[n].dst.sa.sa_family = family;
if (family == AF_INET)
- memcpy(&lookup->results[n].dst.sin.sin_addr, data, NS_INADDRSZ);
+ memcpy(&lookup->results[n].dst.sin.sin_addr,
+ data, NS_INADDRSZ);
else
- memcpy(&lookup->results[n].dst.sin6.sin6_addr, data, NS_IN6ADDRSZ);
+ memcpy(&lookup->results[n].dst.sin6.sin6_addr,
+ data, NS_IN6ADDRSZ);
}
static void parse_response(struct resolv_nameserver *nameserver,
GList *list;
ns_msg msg;
ns_rr rr;
- int i, n, rcode, count;
+ int i, rcode, count;
debug(resolv, "response from %s", nameserver->address);
lookup->ipv4_query = NULL;
}
- for (i = 0, n = 0; i < count; i++) {
+ for (i = 0; i < count; i++) {
ns_parserr(&msg, ns_s_an, i, &rr);
if (ns_rr_class(rr) != ns_c_in)
continue;
g_assert(offsetof(struct sockaddr_in, sin_addr) ==
- offsetof(struct sockaddr_in6, sin6_flowinfo));
+ offsetof(struct sockaddr_in6, sin6_flowinfo));
if (ns_rr_type(rr) == ns_t_a &&
- ns_rr_rdlen(rr) == NS_INADDRSZ) {
+ ns_rr_rdlen(rr) == NS_INADDRSZ) {
add_result(lookup, AF_INET, ns_rr_rdata(rr));
} else if (ns_rr_type(rr) == ns_t_aaaa &&
- ns_rr_rdlen(rr) == NS_IN6ADDRSZ) {
+ ns_rr_rdlen(rr) == NS_IN6ADDRSZ) {
add_result(lookup, AF_INET6, ns_rr_rdata(rr));
}
}
- if (!lookup->ipv4_query && !lookup->ipv6_query)
+ if (lookup->ipv4_query == NULL && lookup->ipv6_query == NULL)
sort_and_return_results(lookup);
destroy_query(query);
if (err)
return -EINVAL;
- /* Do not blindly copy this code elsewhere; it doesn't loop over the
- results using ->ai_next as it should. That's OK in *this* case
- because it was a numeric lookup; we *know* there's only one. */
+ /*
+ * Do not blindly copy this code elsewhere; it doesn't loop over the
+ * results using ->ai_next as it should. That's OK in *this* case
+ * because it was a numeric lookup; we *know* there's only one.
+ */
if (!rp)
return -EINVAL;
return -EIO;
}
+ /*
+ * If nameserver points to localhost ip, their is no need to
+ * bind the socket on any interface.
+ */
+ if (nameserver->resolv->index > 0 &&
+ strncmp(nameserver->address, "127.0.0.1", 9) != 0) {
+ char interface[IF_NAMESIZE];
+
+ memset(interface, 0, IF_NAMESIZE);
+ if (if_indextoname(nameserver->resolv->index,
+ interface) != NULL) {
+ if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE,
+ interface, IF_NAMESIZE) < 0) {
+ close(sk);
+ freeaddrinfo(rp);
+ return -EIO;
+ }
+ }
+ }
+
if (connect(sk, rp->ai_addr, rp->ai_addrlen) < 0) {
close(sk);
freeaddrinfo(rp);
g_io_channel_set_close_on_unref(nameserver->udp_channel, TRUE);
nameserver->udp_watch = g_io_add_watch(nameserver->udp_channel,
- G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP,
- received_udp_data, nameserver);
+ G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP,
+ received_udp_data, nameserver);
return 0;
}
resolv->ref_count = 1;
+ resolv->result_family = AF_UNSPEC;
+
resolv->next_lookup_id = 1;
resolv->query_queue = g_queue_new();
if (resolv == NULL)
return NULL;
- g_atomic_int_inc(&resolv->ref_count);
+ __sync_fetch_and_add(&resolv->ref_count, 1);
return resolv;
}
if (resolv == NULL)
return;
- if (g_atomic_int_dec_and_test(&resolv->ref_count) == FALSE)
+ if (__sync_fetch_and_sub(&resolv->ref_count, 1) != 1)
return;
while ((query = g_queue_pop_head(resolv->query_queue)))
g_free(resolv);
}
-void g_resolv_set_debug(GResolv *resolv,
- GResolvDebugFunc func, gpointer user_data)
+void g_resolv_set_debug(GResolv *resolv, GResolvDebugFunc func,
+ gpointer user_data)
{
if (resolv == NULL)
return;
nameserver->address = g_strdup(address);
nameserver->port = port;
nameserver->flags = flags;
+ nameserver->resolv = resolv;
if (connect_udp_channel(nameserver) < 0) {
free_nameserver(nameserver);
return FALSE;
}
- nameserver->resolv = resolv;
-
resolv->nameserver_list = g_list_append(resolv->nameserver_list,
nameserver);
- debug(resolv, "setting nameserver %s", address);
-
- return TRUE;
-}
-
-void g_resolv_flush_nameservers(GResolv *resolv)
-{
- if (resolv == NULL)
- return;
-
- flush_nameservers(resolv);
-}
-
-static void sort_and_return_results(struct resolv_lookup *lookup)
-{
- char buf[100];
- GResolvResultStatus status;
- char **results = g_try_new0(char *, lookup->nr_results + 1);
- int i, n = 0;
-
- if (!results)
- return;
-
- rfc3484_sort_results(lookup);
-
- for (i = 0; i < lookup->nr_results; i++) {
- if (lookup->results[i].dst.sa.sa_family == AF_INET) {
- if (!inet_ntop(AF_INET, &lookup->results[i].dst.sin.sin_addr,
- buf, sizeof(buf)))
- continue;
- } else if (lookup->results[i].dst.sa.sa_family == AF_INET6) {
- if (!inet_ntop(AF_INET6, &lookup->results[i].dst.sin6.sin6_addr,
- buf, sizeof(buf)))
- continue;
- } else
- continue;
-
- results[n++] = strdup(buf);
- }
- results[n++] = NULL;
+ debug(resolv, "setting nameserver %s", address);
- status = lookup->ipv4_status;
- if (status == G_RESOLV_RESULT_STATUS_SUCCESS)
- status = lookup->ipv6_status;
+ return TRUE;
+}
- lookup->result_func(status, results, lookup->result_data);
+void g_resolv_flush_nameservers(GResolv *resolv)
+{
+ if (resolv == NULL)
+ return;
- g_strfreev(results);
- g_queue_remove(lookup->resolv->lookup_queue, lookup);
- destroy_lookup(lookup);
+ flush_nameservers(resolv);
}
static gint add_query(struct resolv_lookup *lookup, const char *hostname, int type)
query->msgid = buf[0] << 8 | buf[1];
- if (send_query(lookup->resolv, buf, len) < 0)
+ if (send_query(lookup->resolv, buf, len) < 0) {
+ g_free(query);
return -EIO;
+ }
query->resolv = lookup->resolv;
query->lookup = lookup;
int family = resolv->res.nsaddr_list[i].sin_family;
void *sa_addr = &resolv->res.nsaddr_list[i].sin_addr;
- if (family != AF_INET && resolv->res._u._ext.nsaddrs[i]) {
+ if (family != AF_INET &&
+ resolv->res._u._ext.nsaddrs[i]) {
family = AF_INET6;
sa_addr = &resolv->res._u._ext.nsaddrs[i]->sin6_addr;
}
+
if (family != AF_INET && family != AF_INET6)
continue;
}
lookup = g_try_new0(struct resolv_lookup, 1);
- if (!lookup)
+ if (lookup == NULL)
return 0;
lookup->resolv = resolv;
lookup->result_data = user_data;
lookup->id = resolv->next_lookup_id++;
- if (add_query(lookup, hostname, ns_t_a)) {
- g_free(lookup);
- return -EIO;
+ if (resolv->result_family != AF_INET6) {
+ if (add_query(lookup, hostname, ns_t_a)) {
+ g_free(lookup);
+ return -EIO;
+ }
}
- if (add_query(lookup, hostname, ns_t_aaaa)) {
- destroy_query(lookup->ipv4_query);
- g_queue_remove(resolv->query_queue, lookup->ipv4_query);
- g_free(lookup);
- return -EIO;
+
+ if (resolv->result_family != AF_INET) {
+ if (add_query(lookup, hostname, ns_t_aaaa)) {
+ if (resolv->result_family != AF_INET6) {
+ destroy_query(lookup->ipv4_query);
+ g_queue_remove(resolv->query_queue,
+ lookup->ipv4_query);
+ }
+
+ g_free(lookup);
+ return -EIO;
+ }
}
g_queue_push_tail(resolv->lookup_queue, lookup);
return TRUE;
}
-static void find_srcaddr(struct sort_result *res)
-{
- int fd;
- socklen_t sl = sizeof(res->src);
-
- fd = socket(res->dst.sa.sa_family, SOCK_DGRAM, IPPROTO_IP);
- if (fd < 0)
- return;
-
- if (connect(fd, &res->dst.sa, sizeof(res->dst))) {
- close(fd);
- return;
- }
- if (getsockname(fd, &res->src.sa, &sl)) {
- close(fd);
- return;
- }
- res->reachable = TRUE;
- close(fd);
-}
-
-struct gai_table
+gboolean g_resolv_set_address_family(GResolv *resolv, int family)
{
- unsigned char addr[NS_IN6ADDRSZ];
- int mask;
- int value;
-};
-
-static const struct gai_table gai_labels[] = {
- {
- .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
- .mask = 128,
- .value = 0,
- }, {
- .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
- .mask = 16,
- .value = 2,
- }, {
- .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
- .mask = 96,
- .value = 3,
- }, {
- .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 },
- .mask = 96,
- .value = 4,
- }, {
- /* Variations from RFC 3484, matching glibc behaviour */
- .addr = { 0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
- .mask = 10,
- .value = 5,
- }, {
- .addr = { 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
- .mask = 7,
- .value = 6,
- }, {
- .addr = { 0x20, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
- .mask = 32,
- .value = 7,
- }, {
- /* catch-all */
- .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
- .mask = 0,
- .value = 1,
- }
-};
-
-static const struct gai_table gai_precedences[] = {
- {
- .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
- .mask = 128,
- .value = 50,
- }, {
- .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
- .mask = 16,
- .value = 30,
- }, {
- .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
- .mask = 96,
- .value = 20,
- }, {
- .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 },
- .mask = 96,
- .value = 10,
- }, {
- .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
- .mask = 0,
- .value = 40,
- }
-};
+ if (resolv == NULL)
+ return FALSE;
-static unsigned char v4mapped[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 };
+ if (family != AF_UNSPEC && family != AF_INET && family != AF_INET6)
+ return FALSE;
-static gboolean mask_compare(const unsigned char *one, const unsigned char *two, int mask)
-{
- if (mask > 8) {
- if (memcmp(one, two, mask / 8))
- return FALSE;
- one += mask / 8;
- two += mask / 8;
- mask %= 8;
- }
- if (mask && ((*one ^ *two) >> (8-mask)))
- return FALSE;
+ resolv->result_family = family;
return TRUE;
}
-
-static int match_gai_table(struct sockaddr *sa, const struct gai_table *tbl)
-{
- struct sockaddr_in *sin = (void *)sa;
- struct sockaddr_in6 *sin6 = (void *)sa;
- void *addr;
-
- if (sa->sa_family == AF_INET) {
- addr = v4mapped;
- memcpy(v4mapped+12, &sin->sin_addr, NS_INADDRSZ);
- } else
- addr = &sin6->sin6_addr;
-
- while (1) {
- if (mask_compare(addr, tbl->addr, tbl->mask))
- return tbl->value;
- tbl++;
- }
-}
-
-#define DQUAD(_a,_b,_c,_d) ( ((_a)<<24) | ((_b)<<16) | ((_c)<<8) | (_d) )
-#define V4MATCH(addr, a,b,c,d, m) ( ((addr) ^ DQUAD(a,b,c,d)) >> (32 - (m)) )
-
-#define RFC3484_SCOPE_LINK 2
-#define RFC3484_SCOPE_SITE 5
-#define RFC3484_SCOPE_GLOBAL 14
-
-static int addr_scope(struct sockaddr *sa)
-{
- if (sa->sa_family == AF_INET) {
- struct sockaddr_in *sin = (void *)sa;
- guint32 addr = ntohl(sin->sin_addr.s_addr);
-
- if (V4MATCH(addr, 169,254,0,0, 16) ||
- V4MATCH(addr, 127,0,0,0, 8))
- return RFC3484_SCOPE_LINK;
-
- /* Site-local */
- if (V4MATCH(addr, 10,0,0,0, 8) ||
- V4MATCH(addr, 172,16,0,0, 12) ||
- V4MATCH(addr, 192,168,0,0, 16))
- return RFC3484_SCOPE_SITE;
-
- /* Global */
- return RFC3484_SCOPE_GLOBAL;
- } else {
- struct sockaddr_in6 *sin6 = (void *)sa;
-
- /* Multicast addresses have a 4-bit scope field */
- if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
- return sin6->sin6_addr.s6_addr[1] & 0xf;
-
- if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) ||
- IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
- return RFC3484_SCOPE_LINK;
-
- if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
- return RFC3484_SCOPE_SITE;
-
- return RFC3484_SCOPE_GLOBAL;
- }
-}
-
-static int rfc3484_compare(const void *__one, const void *__two)
-{
- const struct sort_result *one = __one;
- const struct sort_result *two = __two;
-
- /* Rule 1: Avoid unusable destinations */
- if (one->reachable && !two->reachable)
- return -1;
- else if (two->reachable && !one->reachable)
- return 1;
-
- /* Rule 2: Prefer matching scope */
- if (one->dst_scope == one->src_scope &&
- two->dst_scope != two->src_scope)
- return -1;
- else if (two->dst_scope == two->src_scope &&
- one->dst_scope != one->src_scope)
- return 1;
-
- /* Rule 3: Avoid deprecated addresses */
-
- /* Rule 4: Prefer home addresses */
-
- /* Rule 5: Prefer matching label */
- if (one->dst_label == one->src_label &&
- two->dst_label != two->src_label)
- return -1;
- else if (two->dst_label == two->src_label &&
- one->dst_label != one->src_label)
- return 1;
-
- /* Rule 6: Prefer higher precedence */
- if (one->precedence > two->precedence)
- return -1;
- else if (two->precedence > one->precedence)
- return 1;
-
- /* Rule 7: Prefer native transport */
-
- /* Rule 8: Prefer smaller scope */
- if (one->dst_scope != two->dst_scope)
- return one->dst_scope - two->dst_scope;
-
- /* Rule 9: Use longest matching prefix */
-
- /* Rule 10: Otherwise, leave the order unchanged */
- if (one < two)
- return -1;
- else
- return 1;
-}
-
-static void rfc3484_sort_results(struct resolv_lookup *lookup)
-{
- int i;
-
- for (i = 0; i < lookup->nr_results; i++) {
- struct sort_result *res = &lookup->results[i];
- find_srcaddr(res);
- res->precedence = match_gai_table(&res->dst.sa, gai_precedences);
- res->dst_label = match_gai_table(&res->dst.sa, gai_labels);
- res->src_label = match_gai_table(&res->src.sa, gai_labels);
- res->dst_scope = addr_scope(&res->dst.sa);
- res->src_scope = addr_scope(&res->src.sa);
- }
-
- qsort(lookup->results, lookup->nr_results, sizeof(struct sort_result),
- rfc3484_compare);
-}