swrap: implement swrap_ipv4_{net,bcast,iface}() helper functions

This makes it easier to implement SOCKET_WRAPPER_IPV4_NETWORK in
the next step.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

diff --git a/src/socket_wrapper.c b/src/socket_wrapper.c
index bd15793f55cb572ed803b45c5758a68e98e904bb..d05182f3c0c7f73ab8f18414f1b81a910a7b06a2 100644 (file)
--- a/src/socket_wrapper.c
+++ b/src/socket_wrapper.c
@@ -1192,6 +1192,84 @@ static void swrap_bind_symbol_all(void)
  * SWRAP HELPER FUNCTIONS
  *********************************************************/
 
+/*
+ * For now we return 127.0.0.0
+ */
+static in_addr_t swrap_ipv4_net(void)
+{
+       static int initialized;
+       static in_addr_t hv;
+       const char *net_str = "127.0.0.0";
+       struct in_addr nv;
+       int ret;
+
+       if (initialized) {
+               return hv;
+       }
+       initialized = 1;
+
+       ret = inet_pton(AF_INET, net_str, &nv);
+       if (ret <= 0) {
+               SWRAP_LOG(SWRAP_LOG_ERROR,
+                         "INVALID IPv4 Network [%s]\n",
+                         net_str);
+               abort();
+       }
+
+       hv = ntohl(nv.s_addr);
+
+       switch (hv) {
+       case 0x7f000000:
+               /* 127.0.0.0 */
+               break;
+       case 0x0a353900:
+               /* 10.53.57.0 */
+               break;
+       default:
+               SWRAP_LOG(SWRAP_LOG_ERROR,
+                         "INVALID IPv4 Network [%s][0x%x] should be "
+                         "127.0.0.0 or 10.53.57.0\n",
+                         net_str, (unsigned)hv);
+               abort();
+       }
+
+       return hv;
+}
+
+/*
+ * This returns 127.255.255.255
+ */
+static in_addr_t swrap_ipv4_bcast(void)
+{
+       in_addr_t hv;
+
+       hv = swrap_ipv4_net();
+       hv |= IN_CLASSA_HOST;
+
+       return hv;
+}
+
+/*
+ * This returns 127.0.0.${iface}
+ */
+static in_addr_t swrap_ipv4_iface(unsigned int iface)
+{
+       in_addr_t hv;
+
+       if (iface == 0 || iface > MAX_WRAPPED_INTERFACES) {
+               SWRAP_LOG(SWRAP_LOG_ERROR,
+                         "swrap_ipv4_iface(%u) invalid!\n",
+                         iface);
+               abort();
+               return -1;
+       }
+
+       hv = swrap_ipv4_net();
+       hv |= iface;
+
+       return hv;
+}
+
 #ifdef HAVE_IPV6
 /*
  * FD00::5357:5FXX
@@ -1442,6 +1520,12 @@ static void socket_wrapper_init_sockets(void)
                return;
        }
 
+       /*
+        * Intialize the static cache early before
+        * any thread is able to start.
+        */
+       (void)swrap_ipv4_net();
+
        socket_wrapper_init_fds_idx();
 
        /* Needs to be called inside the sockets_mutex lock here. */
@@ -1684,7 +1768,7 @@ static int convert_un_in(const struct sockaddr_un *un, struct sockaddr *in, sock
 
                memset(in2, 0, sizeof(*in2));
                in2->sin_family = AF_INET;
-               in2->sin_addr.s_addr = htonl((127<<24) | iface);
+               in2->sin_addr.s_addr = htonl(swrap_ipv4_iface(iface));
                in2->sin_port = htons(prt);
 
                *len = sizeof(*in2);
@@ -1737,6 +1821,8 @@ static int convert_in_un_remote(struct socket_info *si, const struct sockaddr *i
                char u_type = '\0';
                char b_type = '\0';
                char a_type = '\0';
+               const unsigned int sw_net_addr = swrap_ipv4_net();
+               const unsigned int sw_bcast_addr = swrap_ipv4_bcast();
 
                switch (si->type) {
                case SOCK_STREAM:
@@ -1759,12 +1845,12 @@ static int convert_in_un_remote(struct socket_info *si, const struct sockaddr *i
                        is_bcast = 2;
                        type = a_type;
                        iface = socket_wrapper_default_iface();
-               } else if (b_type && addr == 0x7FFFFFFF) {
+               } else if (b_type && addr == sw_bcast_addr) {
                        /* 127.255.255.255 only udp */
                        is_bcast = 1;
                        type = b_type;
                        iface = socket_wrapper_default_iface();
-               } else if ((addr & 0xFFFFFF00) == 0x7F000000) {
+               } else if ((addr & 0xFFFFFF00) == sw_net_addr) {
                        /* 127.0.0.X */
                        is_bcast = 0;
                        type = u_type;
@@ -1869,6 +1955,8 @@ static int convert_in_un_alloc(struct socket_info *si, const struct sockaddr *in
                char d_type = '\0';
                char b_type = '\0';
                char a_type = '\0';
+               const unsigned int sw_net_addr = swrap_ipv4_net();
+               const unsigned int sw_bcast_addr = swrap_ipv4_bcast();
 
                prt = ntohs(in->sin_port);
 
@@ -1899,12 +1987,12 @@ static int convert_in_un_alloc(struct socket_info *si, const struct sockaddr *in
                        is_bcast = 2;
                        type = a_type;
                        iface = socket_wrapper_default_iface();
-               } else if (b_type && addr == 0x7FFFFFFF) {
+               } else if (b_type && addr == sw_bcast_addr) {
                        /* 127.255.255.255 only udp */
                        is_bcast = 1;
                        type = b_type;
                        iface = socket_wrapper_default_iface();
-               } else if ((addr & 0xFFFFFF00) == 0x7F000000) {
+               } else if ((addr & 0xFFFFFF00) == sw_net_addr) {
                        /* 127.0.0.X */
                        is_bcast = 0;
                        type = u_type;
@@ -1922,8 +2010,7 @@ static int convert_in_un_alloc(struct socket_info *si, const struct sockaddr *in
                        ZERO_STRUCT(bind_in);
                        bind_in.sin_family = in->sin_family;
                        bind_in.sin_port = in->sin_port;
-                       bind_in.sin_addr.s_addr = htonl(0x7F000000 | iface);
-
+                       bind_in.sin_addr.s_addr = htonl(swrap_ipv4_iface(iface));
                        si->bindname.sa_socklen = blen;
                        memcpy(&si->bindname.sa.in, &bind_in, blen);
                }
@@ -3554,8 +3641,8 @@ static int swrap_auto_bind(int fd, struct socket_info *si, int family)
 
                memset(&in, 0, sizeof(in));
                in.sin_family = AF_INET;
-               in.sin_addr.s_addr = htonl(127<<24 |
-                                          socket_wrapper_default_iface());
+               in.sin_addr.s_addr = htonl(swrap_ipv4_iface(
+                                          socket_wrapper_default_iface()));
 
                si->myname = (struct swrap_address) {
                        .sa_socklen = sizeof(in),