This allows users to specify which interface outbound
requests will originate from on multi-homed machines.
Also support setting list of servers as a comma-separated
string.
Signed-off-by: Ben Greear <greearb_at_candelatech.com>
---
:100644 100644 368c73a... 3b4ff13... M ares.h
:100644 100644 1f561aa... d5b768c... M ares_init.c
:100644 100644 d00368a... b43fdff... M ares_options.c
:100644 100644 0df5cb7... 6f86a3a... M ares_private.h
:100644 100644 3ef1ddb... e416132... M ares_process.c
ares.h | 19 +++++++++
ares_init.c | 24 +++++++++++
ares_options.c | 124 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ares_private.h | 7 +++
ares_process.c | 38 +++++++++++++++--
5 files changed, 208 insertions(+), 4 deletions(-)
diff --git a/ares.h b/ares.h
index 368c73a..3b4ff13 100644
--- a/ares.h
+++ b/ares.h
@@ -313,6 +313,20 @@ CARES_EXTERN void ares_destroy(ares_channel channel);
CARES_EXTERN void ares_cancel(ares_channel channel);
+/* These next 3 configure local binding for the out-going socket
+ * connection. Use these to specify source IP and/or network device
+ * on multi-homed systems.
+ */
+CARES_EXTERN void ares_set_local_ip4(ares_channel channel, uint32_t local_ip);
+
+/* local_ip6 should be 16 bytes in length */
+CARES_EXTERN void ares_set_local_ip6(ares_channel channel,
+ const unsigned char* local_ip6);
+
+/* local_dev_name should be null terminated. */
+CARES_EXTERN void ares_set_local_dev(ares_channel channel,
+ const char* local_dev_name);
+
CARES_EXTERN void ares_set_socket_callback(ares_channel channel,
ares_sock_create_callback callback,
void *user_data);
@@ -496,6 +510,7 @@ CARES_EXTERN void ares_free_data(void *dataptr);
CARES_EXTERN const char *ares_strerror(int code);
+/* TODO: Hold port here as well. */
struct ares_addr_node {
struct ares_addr_node *next;
int family;
@@ -508,6 +523,10 @@ struct ares_addr_node {
CARES_EXTERN int ares_set_servers(ares_channel channel,
struct ares_addr_node *servers);
+/* Incomming string format: host[:port][,host[:port]]... */
+CARES_EXTERN int ares_set_servers_csv(ares_channel channel,
+ const char* servers);
+
CARES_EXTERN int ares_get_servers(ares_channel channel,
struct ares_addr_node **servers);
diff --git a/ares_init.c b/ares_init.c
index 1f561aa..d5b768c 100644
--- a/ares_init.c
+++ b/ares_init.c
@@ -168,6 +168,10 @@ int ares_init_options(ares_channel *channelptr, struct ares_options *options,
channel->last_server = 0;
channel->last_timeout_processed = (time_t)now.tv_sec;
+ memset(&channel->local_dev_name, 0, sizeof(channel->local_dev_name));
+ channel->local_ip4 = 0;
+ memset(&channel->local_ip6, 0, sizeof(channel->local_ip6));
+
/* Initialize our lists of queries */
ares__init_list_head(&(channel->all_queries));
for (i = 0; i < ARES_QID_TABLE_SIZE; i++)
@@ -1594,6 +1598,26 @@ unsigned short ares__generate_new_id(rc4_key* key)
return r;
}
+void ares_set_local_ip4(ares_channel channel, uint32_t local_ip)
+{
+ channel->local_ip4 = local_ip;
+}
+
+/* local_ip6 should be 16 bytes in length */
+void ares_set_local_ip6(ares_channel channel,
+ const unsigned char* local_ip6) {
+ memcpy(&channel->local_ip6, local_ip6, sizeof(channel->local_ip6));
+}
+
+/* local_dev_name should be null terminated. */
+void ares_set_local_dev(ares_channel channel,
+ const char* local_dev_name) {
+ strncpy(channel->local_dev_name, local_dev_name,
+ sizeof(channel->local_dev_name));
+ channel->local_dev_name[sizeof(channel->local_dev_name) - 1] = 0;
+}
+
+
void ares_set_socket_callback(ares_channel channel,
ares_sock_create_callback cb,
void *data)
diff --git a/ares_options.c b/ares_options.c
index d00368a..b43fdff 100644
--- a/ares_options.c
+++ b/ares_options.c
@@ -125,3 +125,127 @@ int ares_set_servers(ares_channel channel,
return ARES_SUCCESS;
}
+
+/* Incomming string format: host[:port][,host[:port]]... */
+int ares_set_servers_csv(ares_channel channel,
+ const char* _csv)
+{
+ struct ares_addr_node *srvr;
+ int num_srvrs = 0;
+ int i;
+ char* csv = NULL;
+ char* ptr;
+ char* start_host;
+ int port;
+ bool found_port;
+ int rv = ARES_SUCCESS;
+ struct ares_addr_node *servers = NULL;
+ struct ares_addr_node *last = NULL;
+
+ if (ares_library_initialized() != ARES_SUCCESS)
+ return ARES_ENOTINITIALIZED;
+
+ if (!channel)
+ return ARES_ENODATA;
+
+ ares__destroy_servers_state(channel);
+
+ i = strlen(_csv);
+ if (i == 0)
+ return ARES_SUCCESS; /* blank all servers */
+
+ csv = malloc(i + 2);
+ strcpy(csv, _csv);
+ if (csv[i-1] != ',') { /* make parsing easier by ensuring ending ',' */
+ csv[i] = ',';
+ csv[i+1] = 0;
+ }
+
+ ptr = csv;
+ start_host = csv;
+ found_port = false;
+ for (ptr; *ptr; ptr++) {
+ if (*ptr == ',') {
+ char* pp = ptr - 1;
+ struct in_addr in4;
+ struct in6_addr in6;
+ struct ares_addr_node *s = NULL;
+
+ *ptr = 0; /* null terminate host:port string */
+ /* Got an entry..see if port was specified. */
+ while (pp > start_host) {
+ if (*pp == ':')
+ break; /* yes */
+ if (!isdigit(*pp)) {
+ /* Found end of digits before we found :, so wasn't a port */
+ pp = ptr;
+ break;
+ }
+ pp--;
+ }
+ if ((pp != start_host) && ((pp + 1) < ptr)) {
+ /* Found it. */
+ found_port = true;
+ port = atoi(pp + 1);
+ *pp = 0; /* null terminate host */
+ }
+ /* resolve host, try ipv4 first, rslt is in network byte order */
+ rv = inet_pton(AF_INET, start_host, &in4);
+ if (!rv) {
+ /* Ok, try IPv6 then */
+ rv = inet_pton(AF_INET6, start_host, &in6);
+ if (!rv) {
+ rv = ARES_EBADSTR;
+ goto out;
+ }
+ /* was ipv6, add new server */
+ s = malloc(sizeof(*s));
+ if (!s) {
+ rv = ARES_ENOMEM;
+ goto out;
+ }
+ s->family = AF_INET6;
+ memcpy(&s->addr, &in6, sizeof(struct ares_in6_addr));
+ }
+ else {
+ /* was ipv4, add new server */
+ s = malloc(sizeof(*s));
+ if (!s) {
+ rv = ARES_ENOMEM;
+ goto out;
+ }
+ s->family = AF_INET;
+ memcpy(&s->addr, &in4, sizeof(struct in_addr));
+ }
+ if (s) {
+ /* TODO: Add port to ares_addr_node and assign it here. */
+
+ s->next = NULL;
+ if (last) {
+ last->next = s;
+ }
+ else {
+ servers = s;
+ last = s;
+ }
+ }
+
+ /* Set up for next one */
+ found_port = false;
+ start_host = ptr + 1;
+ }
+ }
+
+ rv = ares_set_servers(channel, servers);
+
+ out:
+ if (csv)
+ free(csv);
+ while (servers) {
+ struct ares_addr_node *s = servers;
+ servers = servers->next;
+ free(s);
+ }
+
+ return rv;
+}
diff --git a/ares_private.h b/ares_private.h
index 0df5cb7..6f86a3a 100644
--- a/ares_private.h
+++ b/ares_private.h
@@ -257,6 +257,13 @@ struct ares_channeldata {
int nsort;
char *lookups;
+ /* For binding to local devices and/or IP addresses. Leave
+ * them null/zero for no binding.
+ */
+ char local_dev_name[32];
+ uint32_t local_ip4;
+ unsigned char local_ip6[16];
+
int optmask; /* the option bitfield passed in at init time */
/* Server addresses and communications state */
diff --git a/ares_process.c b/ares_process.c
index 3ef1ddb..e416132 100644
--- a/ares_process.c
+++ b/ares_process.c
@@ -91,7 +91,6 @@ static void skip_server(ares_channel channel, struct query *query,
int whichserver);
static void next_server(ares_channel channel, struct query *query,
struct timeval *now);
-static int configure_socket(ares_socket_t s, ares_channel channel);
static int open_tcp_socket(ares_channel channel, struct server_state *server);
static int open_udp_socket(ares_channel channel, struct server_state *server);
static int same_questions(const unsigned char *qbuf, int qlen,
@@ -869,7 +868,7 @@ static int setsocknonblock(ares_socket_t sockfd, /* operate on this */
#endif
}
-static int configure_socket(ares_socket_t s, ares_channel channel)
+static int configure_socket(ares_socket_t s, int family, ares_channel channel)
{
setsocknonblock(s, TRUE);
@@ -892,6 +891,37 @@ static int configure_socket(ares_socket_t s, ares_channel channel)
sizeof(channel->socket_receive_buffer_size)) == -1)
return -1;
+#ifdef SO_BINDTODEVICE
+ if (channel->local_dev_name[0]) {
+ if (setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE,
+ channel->local_dev_name, sizeof(channel->local_dev_name))) {
+ /* Only root can do this, and usually not fatal if it doesn't work, so */
+ /* just continue on. */
+ }
+ }
+#endif
+
+ if (family == AF_INET) {
+ if (channel->local_ip4) {
+ struct sockaddr_in sa;
+ memset(&sa, 0, sizeof(sa));
+ sa.sin_family = AF_INET;
+ sa.sin_addr.s_addr = htonl(channel->local_ip4);
+ if (bind(s, (struct sockaddr*)&sa, sizeof(sa)) < 0)
+ return -1;
+ }
+ }
+ else if (family == AF_INET6) {
+ if (memcmp(channel->local_ip6, &in6addr_any, sizeof(channel->local_ip6)) != 0) {
+ struct sockaddr_in6 sa;
+ memset(&sa, 0, sizeof(sa));
+ sa.sin6_family = AF_INET6;
+ memcpy(&sa.sin6_addr, channel->local_ip6, sizeof(channel->local_ip6));
+ if (bind(s, (struct sockaddr*)&sa, sizeof(sa)) < 0)
+ return -1;
+ }
+ }
+
return 0;
}
@@ -936,7 +966,7 @@ static int open_tcp_socket(ares_channel channel, struct server_state *server)
return -1;
/* Configure it. */
- if (configure_socket(s, channel) < 0)
+ if (configure_socket(s, server->addr.family, channel) < 0)
{
sclose(s);
return -1;
@@ -1028,7 +1058,7 @@ static int open_udp_socket(ares_channel channel, struct server_state *server)
return -1;
/* Set the socket non-blocking. */
- if (configure_socket(s, channel) < 0)
+ if (configure_socket(s, server->addr.family, channel) < 0)
{
sclose(s);
return -1;
--
1.6.2.5
Received on 2010-05-25