child: use a list of listen_fds instead of one single listenfd.

This prepares listenting on multiple sockets, which will be ussed to
fix listening on the wildcard (listen on both ipv6 and ipv4) and
help add the support for multiple Listen statements in the config

Signed-off-by: Michael Adam <obnox@samba.org>

src/child.c

@@ -32,7 +32,7 @@
 #include "utils.h"
 #include "conf.h"
 
-static int listenfd;
+static vector_t listen_fds;
 
 /*
  * Stores the internal data needed for each child (connection)
@@ -186,6 +186,10 @@ static void child_main (struct child_s *ptr)
         int connfd;
         struct sockaddr *cliaddr;
         socklen_t clilen;
+        fd_set rfds;
+        int maxfd = 0;
+        ssize_t i;
+        int ret;
 
         cliaddr = (struct sockaddr *)
                         safemalloc (sizeof(struct sockaddr_storage));
@@ -197,11 +201,65 @@ static void child_main (struct child_s *ptr)
 
         ptr->connects = 0;
 
+        /*
+         * We have to wait for connections on multiple fds,
+         * so use select.
+         */
+
+        FD_ZERO(&rfds);
+
+        for (i = 0; i < vector_length(listen_fds); i++) {
+                int *fd = (int *) vector_getentry(listen_fds, i, NULL);
+
+                socket_nonblocking(*fd);
+                FD_SET(*fd, &rfds);
+                maxfd = max(maxfd, *fd);
+        }
+
         while (!config.quit) {
+                int listenfd = -1;
+
                 ptr->status = T_WAITING;
 
                 clilen = sizeof(struct sockaddr_storage);
 
+                ret = select(maxfd + 1, &rfds, NULL, NULL, NULL);
+                if (ret == -1) {
+                        log_message (LOG_ERR, "error calling select: %s",
+                                     strerror(errno));
+                        exit(1);
+                } else if (ret == 0) {
+                        log_message (LOG_WARNING, "Strange: select returned 0 "
+                                     "but we did not specify a timeout...");
+                        continue;
+                }
+
+                for (i = 0; i < vector_length(listen_fds); i++) {
+                        int *fd = (int *) vector_getentry(listen_fds, i, NULL);
+
+                        if (FD_ISSET(*fd, &rfds)) {
+                                /*
+                                 * only accept the connection on the first
+                                 * fd that we find readable. - fair?
+                                 */
+                                listenfd = *fd;
+                                break;
+                        }
+                }
+
+                if (listenfd == -1) {
+                        log_message(LOG_WARNING, "Strange: None of our listen "
+                                    "fds was readable after select");
+                        continue;
+                }
+
+                socket_blocking(listenfd);
+
+                /*
+                 * We have a socket that is readable.
+                 * Continue handling this connection.
+                 */
+
                 connfd = accept (listenfd, cliaddr, &clilen);
 
 #ifndef NDEBUG
@@ -466,11 +524,31 @@ void child_kill_children (int sig)
 
 int child_listening_sock (const char *addr, uint16_t port)
 {
-        listenfd = listen_sock (addr, port);
-        return listenfd;
+        int ret;
+
+        if (listen_fds == NULL) {
+                listen_fds = vector_create();
+                if (listen_fds == NULL) {
+                        log_message (LOG_ERR, "Could not create the list "
+                                     "of listening fds");
+                        return -1;
+                }
+        }
+
+        ret = listen_sock (addr, port, listen_fds);
+        return ret;
 }
 
 void child_close_sock (void)
 {
-        close (listenfd);
+        ssize_t i;
+
+        for (i = 0; i < vector_length(listen_fds); i++) {
+                int *fd = (int *) vector_getentry(listen_fds, i, NULL);
+                close (*fd);
+        }
+
+        vector_delete(listen_fds);
+
+        listen_fds = NULL;
 }

src/sock.c

@@ -166,7 +166,7 @@ int socket_blocking (int sock)
  * Start listening on a socket. Create a socket with the selected port.
  * The socket fd is returned upon success, -1 upon error.
  */
-int listen_sock (const char *addr, uint16_t port)
+int listen_sock (const char *addr, uint16_t port, vector_t listen_fds)
 {
         struct addrinfo hints, *result, *rp;
         char portstr[6];
@@ -174,6 +174,7 @@ int listen_sock (const char *addr, uint16_t port)
         const int on = 1;
 
         assert (port > 0);
+        assert (listen_fds != NULL);
 
         memset (&hints, 0, sizeof (struct addrinfo));
         hints.ai_family = AF_UNSPEC;
@@ -224,9 +225,11 @@ int listen_sock (const char *addr, uint16_t port)
                 return -1;
         }
 
+        vector_append(listen_fds, &listenfd, sizeof(int));
+
         freeaddrinfo (result);
 
-        return listenfd;
+        return 0;
 }
 
 /*

src/sock.h

@@ -28,8 +28,10 @@
 
 #define MAXLINE (1024 * 4)
 
+#include "vector.h"
+
 extern int opensock (const char *host, int port, const char *bind_to);
-extern int listen_sock (const char *addr, uint16_t port);
+extern int listen_sock (const char *addr, uint16_t port, vector_t listen_fds);
 
 extern int socket_nonblocking (int sock);
 extern int socket_blocking (int sock);