X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;ds=sidebyside;f=src%2Fsocket-proxy%2Fsocket-proxyd.c;h=054a27a71b9bb185353388bac7a72bc1a3297a3d;hb=f4bd42aa3c9bfbb0fa7a597b715fc3ee8f336764;hp=7fe3e525523bfcec0ba455093a084576eb686125;hpb=b6818c7d10659495de6424bad8e019be1001979f;p=elogind.git

diff --git a/src/socket-proxy/socket-proxyd.c b/src/socket-proxy/socket-proxyd.c
index 7fe3e5255..054a27a71 100644
--- a/src/socket-proxy/socket-proxyd.c
+++ b/src/socket-proxy/socket-proxyd.c
@@ -64,10 +64,13 @@ struct connection {
 };
 
 static void free_connection(struct connection *c) {
-        log_debug("Freeing fd=%d (conn %p).", c->fd, c);
-        sd_event_source_unref(c->w);
-        close_nointr_nofail(c->fd);
-        free(c);
+        if (c != NULL) {
+                log_debug("Freeing fd=%d (conn %p).", c->fd, c);
+                sd_event_source_unref(c->w);
+                if (c->fd > 0)
+                        close_nointr_nofail(c->fd);
+                free(c);
+        }
 }
 
 static int add_event_to_connection(struct connection *c, uint32_t events) {
@@ -122,7 +125,8 @@ static int send_buffer(struct connection *sender) {
         int r = 0;
 
         /* We cannot assume that even a partial send() indicates that
-         * the next send() will block. Loop until it does. */
+         * the next send() will return EAGAIN or EWOULDBLOCK. Loop until
+         * it does. */
         while (sender->buffer_filled_len > sender->buffer_sent_len) {
                 len = send(receiver->fd, sender->buffer + sender->buffer_sent_len, sender->buffer_filled_len - sender->buffer_sent_len, 0);
                 log_debug("send(%d, ...)=%ld", receiver->fd, len);
@@ -132,7 +136,7 @@ static int send_buffer(struct connection *sender) {
                                 return -errno;
                         }
                         else {
-                                /* send() is in a blocking state. */
+                                /* send() is in a would-block state. */
                                 break;
                         }
                 }
@@ -167,7 +171,8 @@ static int send_buffer(struct connection *sender) {
                 return r;
         }
 
-        /* If we sent everything without blocking, the buffer is now empty. */
+        /* If we sent everything without any issues (would-block or
+         * partial send), the buffer is now empty. */
         sender->buffer_filled_len = 0;
         sender->buffer_sent_len = 0;
 
@@ -242,7 +247,7 @@ static int transfer_data_cb(sd_event_source *s, int fd, uint32_t revents, void *
         return r;
 }
 
-/* Once sending to the server is unblocked, set up the real watchers. */
+/* Once sending to the server is ready, set up the real watchers. */
 static int connected_to_server_cb(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
         struct sd_event *e = NULL;
         struct connection *c_server_to_client = (struct connection *) userdata;
@@ -345,19 +350,27 @@ static int get_server_connection_fd(const struct proxy *proxy) {
         return server_fd;
 }
 
-static int accept_cb(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
-        struct proxy *proxy = (struct proxy *) userdata;
-        struct connection *c_server_to_client;
+static int do_accept(sd_event *e, struct proxy *p, int fd) {
+        struct connection *c_server_to_client = NULL;
         struct connection *c_client_to_server = NULL;
         int r = 0;
         union sockaddr_union sa;
         socklen_t salen = sizeof(sa);
+        int client_fd, server_fd;
+
+        client_fd = accept4(fd, (struct sockaddr *) &sa, &salen, SOCK_NONBLOCK|SOCK_CLOEXEC);
+        if (client_fd < 0) {
+                if (errno == EAGAIN || errno == EWOULDBLOCK)
+                    return -errno;
+                log_error("Error %d accepting client connection: %m", errno);
+                r = -errno;
+                goto fail;
+        }
 
-        assert(revents & EPOLLIN);
-
-        c_server_to_client = new0(struct connection, 1);
-        if (c_server_to_client == NULL) {
-                log_oom();
+        server_fd = get_server_connection_fd(p);
+        if (server_fd < 0) {
+                log_error("Error initiating server connection.");
+                r = server_fd;
                 goto fail;
         }
 
@@ -367,18 +380,14 @@ static int accept_cb(sd_event_source *s, int fd, uint32_t revents, void *userdat
                 goto fail;
         }
 
-        c_server_to_client->fd = get_server_connection_fd(proxy);
-        if (c_server_to_client->fd < 0) {
-                log_error("Error initiating server connection.");
-                goto fail;
-        }
-
-        c_client_to_server->fd = accept4(fd, (struct sockaddr *) &sa, &salen, SOCK_NONBLOCK|SOCK_CLOEXEC);
-        if (c_client_to_server->fd < 0) {
-                log_error("Error accepting client connection.");
+        c_server_to_client = new0(struct connection, 1);
+        if (c_server_to_client == NULL) {
+                log_oom();
                 goto fail;
         }
 
+        c_client_to_server->fd = client_fd;
+        c_server_to_client->fd = server_fd;
 
         if (sa.sa.sa_family == AF_INET || sa.sa.sa_family == AF_INET6) {
                 char sa_str[INET6_ADDRSTRLEN];
@@ -399,7 +408,7 @@ static int accept_cb(sd_event_source *s, int fd, uint32_t revents, void *userdat
         log_debug("Server fd=%d (conn %p) successfully initialized.", c_server_to_client->fd, c_server_to_client);
 
         /* Initialize watcher for send to server; this shows connectivity. */
-        r = sd_event_add_io(sd_event_get(s), c_server_to_client->fd, EPOLLOUT, connected_to_server_cb, c_server_to_client, &c_server_to_client->w);
+        r = sd_event_add_io(e, c_server_to_client->fd, EPOLLOUT, connected_to_server_cb, c_server_to_client, &c_server_to_client->w);
         if (r < 0) {
                 log_error("Error %d creating connectivity watcher for fd=%d: %s", r, c_server_to_client->fd, strerror(-r));
                 goto fail;
@@ -417,7 +426,36 @@ fail:
         free_connection(c_server_to_client);
 
 finish:
-        /* Preserve the main loop even if a single proxy setup fails. */
+        return r;
+}
+
+static int accept_cb(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        struct proxy *p = (struct proxy *) userdata;
+        sd_event *e = NULL;
+        int r = 0;
+
+        assert(revents & EPOLLIN);
+
+        e = sd_event_get(s);
+
+        for (;;) {
+                r = do_accept(e, p, fd);
+                if (r == -EAGAIN || r == -EWOULDBLOCK)
+                        break;
+                if (r < 0) {
+                        log_error("Error %d while trying to accept: %s", r, strerror(-r));
+                        break;
+                }
+        }
+
+        /* Re-enable the watcher. */
+        r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT);
+        if (r < 0) {
+                log_error("Error %d while re-enabling listener with ONESHOT: %s", r, strerror(-r));
+                return r;
+        }
+
+        /* Preserve the main loop even if a single accept() fails. */
         return 1;
 }
 
@@ -434,7 +472,7 @@ static int run_main_loop(struct proxy *proxy) {
 
         r = fd_nonblock(proxy->listen_fd, true);
         if (r < 0) {
-                log_error("Failed to make listen file descriptor non-blocking: %s", strerror(-r));
+                log_error("Failed to make listen file descriptor nonblocking: %s", strerror(-r));
                 return r;
         }
 
@@ -442,7 +480,15 @@ static int run_main_loop(struct proxy *proxy) {
 
         r = sd_event_add_io(e, proxy->listen_fd, EPOLLIN, accept_cb, proxy, &w_accept);
         if (r < 0) {
-                log_error("Failed to add event IO source: %s", strerror(-r));
+                log_error("Error %d while adding event IO source: %s", r, strerror(-r));
+                return r;
+        }
+
+        /* Set the watcher to oneshot in case other processes are also
+         * watching to accept(). */
+        r = sd_event_source_set_enabled(w_accept, SD_EVENT_ONESHOT);
+        if (r < 0) {
+                log_error("Error %d while setting event IO source to ONESHOT: %s", r, strerror(-r));
                 return r;
         }
 
@@ -572,7 +618,6 @@ int main(int argc, char *argv[]) {
                 }
         }
 
-        /* @TODO: Check if this proxy can work with datagram sockets. */
         r = sd_is_socket(p.listen_fd, 0, SOCK_STREAM, 1);
         if (r < 0) {
                 log_error("Error %d while checking inherited socket: %s", r, strerror(-r));