s3: IPv6 enabled DNS connections for ADS client

This patch makes DNS client connections protocol independent.
For example DNS updates. This makes IPv6-only clients possible.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11283

Back-port from fff774eda3ed04d319232b108a94282af24cc6b0

Signed-off-by: David Holder <david.holder@erion.co.uk>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Ralph Böhme <rb@sernet.de>
Autobuild-User(v4-1-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-1-test): Tue Jun  2 01:55:28 CEST 2015 on sn-devel-104

diff --git a/lib/addns/dns.h b/lib/addns/dns.h
index bf2ade387b93c78179fbce02d401624919f4c4c5..de1897b6e87bef9b1603c729aade9418209488d7 100644 (file)
--- a/lib/addns/dns.h
+++ b/lib/addns/dns.h
@@ -222,7 +222,7 @@ struct dns_update_request {
 struct dns_connection {
        int32_t hType;
        int s;
-       struct sockaddr RecvAddr;
+       struct sockaddr_storage RecvAddr;
 };
 
 struct dns_buffer {

diff --git a/lib/addns/dnssock.c b/lib/addns/dnssock.c
index 5f9951913587f2edb83aa51de00d50ed11925b87..bab20a4b9e90374707ce36cc5068e7afff66f830 100644 (file)
--- a/lib/addns/dnssock.c
+++ b/lib/addns/dnssock.c
@@ -27,6 +27,7 @@
 #include <sys/time.h>
 #include <unistd.h>
 #include "system/select.h"
+#include "../lib/util/debug.h"
 
 static int destroy_dns_connection(struct dns_connection *conn)
 {
@@ -40,42 +41,58 @@ static DNS_ERROR dns_tcp_open( const char *nameserver,
                               TALLOC_CTX *mem_ctx,
                               struct dns_connection **result )
 {
-       uint32_t ulAddress;
-       struct hostent *pHost;
-       struct sockaddr_in s_in;
+       struct addrinfo hints;
+       struct addrinfo *ai_result = NULL;
+       struct addrinfo *rp;
        struct dns_connection *conn;
-       int res;
+       int ret;
+       char service[16];
+
+       snprintf(service, sizeof(service), "%d", DNS_TCP_PORT);
 
        if (!(conn = talloc(mem_ctx, struct dns_connection))) {
                return ERROR_DNS_NO_MEMORY;
        }
 
-       if ( (ulAddress = inet_addr( nameserver )) == INADDR_NONE ) {
-               if ( (pHost = gethostbyname( nameserver )) == NULL ) {
-                       TALLOC_FREE(conn);
-                       return ERROR_DNS_INVALID_NAME_SERVER;
-               }
-               memcpy( &ulAddress, pHost->h_addr, pHost->h_length );
-       }
+       memset(&hints, 0, sizeof(struct addrinfo));
+       hints.ai_family = AF_UNSPEC;
+       hints.ai_socktype = SOCK_STREAM;
+       hints.ai_flags = 0;
+       hints.ai_protocol = IPPROTO_TCP;
 
-       conn->s = socket( PF_INET, SOCK_STREAM, 0 );
-       if (conn->s == -1) {
-               TALLOC_FREE(conn);
-               return ERROR_DNS_CONNECTION_FAILED;
+       ret = getaddrinfo(nameserver, service, &hints, &ai_result);
+       if (ret != 0) {
+               DEBUG(1,("dns_tcp_open: getaddrinfo: %s\n", gai_strerror(ret)));
+               return ERROR_DNS_INVALID_NAME_SERVER;
        }
 
-       talloc_set_destructor(conn, destroy_dns_connection);
+       for (rp = ai_result; rp != NULL; rp = rp->ai_next) {
+               conn->s = socket(rp->ai_family,
+                               rp->ai_socktype,
+                               rp->ai_protocol);
+               if (conn->s == -1) {
+                       continue;
+               }
+               do {
+                       ret = connect(conn->s, rp->ai_addr, rp->ai_addrlen);
+               } while ((ret == -1) && (errno == EINTR));
+               if (ret != -1) {
+                       /* Successful connect */
+                       break;
+               }
+               close(conn->s);
+       }
 
-       s_in.sin_family = AF_INET;
-       s_in.sin_addr.s_addr = ulAddress;
-       s_in.sin_port = htons( DNS_TCP_PORT );
+       freeaddrinfo(ai_result);
 
-       res = connect(conn->s, (struct sockaddr*)&s_in, sizeof( s_in ));
-       if (res == -1) {
+       /* Failed to connect with any address */
+       if (rp == NULL) {
                TALLOC_FREE(conn);
                return ERROR_DNS_CONNECTION_FAILED;
        }
 
+       talloc_set_destructor(conn, destroy_dns_connection);
+
        conn->hType = DNS_TCP;
 
        *result = conn;
@@ -89,44 +106,72 @@ static DNS_ERROR dns_udp_open( const char *nameserver,
                               TALLOC_CTX *mem_ctx,
                               struct dns_connection **result )
 {
-       unsigned long ulAddress;
-       struct hostent *pHost;
-       struct sockaddr_in RecvAddr;
+       struct addrinfo hints;
+       struct addrinfo *ai_result = NULL;
+       struct addrinfo *rp;
+       struct sockaddr_storage RecvAddr;
        struct dns_connection *conn;
+       int ret;
+       socklen_t RecvAddrLen;
+       char service[16];
+
+       snprintf(service, sizeof(service), "%d", DNS_UDP_PORT);
 
        if (!(conn = talloc(NULL, struct dns_connection))) {
                return ERROR_DNS_NO_MEMORY;
        }
 
-       if ( (ulAddress = inet_addr( nameserver )) == INADDR_NONE ) {
-               if ( (pHost = gethostbyname( nameserver )) == NULL ) {
-                       TALLOC_FREE(conn);
-                       return ERROR_DNS_INVALID_NAME_SERVER;
+       memset(&hints, 0, sizeof(struct addrinfo));
+       hints.ai_family = AF_UNSPEC;
+       hints.ai_socktype = SOCK_DGRAM;
+       hints.ai_flags = 0;
+       hints.ai_protocol = IPPROTO_UDP;
+
+       ret = getaddrinfo(nameserver, service, &hints, &ai_result);
+       if (ret != 0) {
+               DEBUG(1,("dns_ucp_open:getaddrinfo: %s\n", gai_strerror(ret)));
+               TALLOC_FREE(conn);
+               return ERROR_DNS_INVALID_NAME_SERVER;
+       }
+
+       for (rp = ai_result; rp != NULL; rp = rp->ai_next) {
+               conn->s = socket(rp->ai_family,
+                               rp->ai_socktype,
+                               rp->ai_protocol);
+               if (conn->s == -1) {
+                       continue;
                }
-               memcpy( &ulAddress, pHost->h_addr, pHost->h_length );
+               ret = connect(conn->s, rp->ai_addr, rp->ai_addrlen);
+               if (ret != -1) {
+                       /* Successful connect */
+                       break;
+               }
+               close(conn->s);
        }
 
-       /* Create a socket for sending data */
+       freeaddrinfo(ai_result);
 
-       conn->s = socket( AF_INET, SOCK_DGRAM, IPPROTO_UDP );
-       if (conn->s == -1) {
+       /* Failed to connect with any address */
+       if (rp == NULL) {
                TALLOC_FREE(conn);
-               return ERROR_DNS_CONNECTION_FAILED;
+                return ERROR_DNS_CONNECTION_FAILED;
        }
 
        talloc_set_destructor(conn, destroy_dns_connection);
 
        /* Set up the RecvAddr structure with the IP address of
-          the receiver (in this example case "123.456.789.1")
-          and the specified port number. */
+          the receiver and the specified port number. */
 
-       ZERO_STRUCT(RecvAddr);
-       RecvAddr.sin_family = AF_INET;
-       RecvAddr.sin_port = htons( DNS_UDP_PORT );
-       RecvAddr.sin_addr.s_addr = ulAddress;
+       RecvAddrLen = sizeof(RecvAddr);
+       if (getpeername(conn->s,
+                       (struct sockaddr *)&RecvAddr,
+                       &RecvAddrLen) == -1) {
+               TALLOC_FREE(conn);
+               return ERROR_DNS_CONNECTION_FAILED;
+       }
 
        conn->hType = DNS_UDP;
-       memcpy( &conn->RecvAddr, &RecvAddr, sizeof( struct sockaddr_in ) );
+       memcpy(&conn->RecvAddr, &RecvAddr, sizeof(struct sockaddr_storage));
 
        *result = conn;
        return ERROR_DNS_SUCCESS;