socket: Add backlog parameter to socket_listen

Current parameter was always one.  We continue with that value for now
in all callers.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
---
Moved trace to socket_listen

include/qemu/sockets.h

@@ -41,7 +41,7 @@ int unix_connect(const char *path, Error **errp);
 
 SocketAddress *socket_parse(const char *str, Error **errp);
 int socket_connect(SocketAddress *addr, Error **errp);
-int socket_listen(SocketAddress *addr, Error **errp);
+int socket_listen(SocketAddress *addr, int num, Error **errp);
 void socket_listen_cleanup(int fd, Error **errp);
 int socket_dgram(SocketAddress *remote, SocketAddress *local, Error **errp);
 

io/channel-socket.c

@@ -202,7 +202,7 @@ int qio_channel_socket_listen_sync(QIOChannelSocket *ioc,
     int fd;
 
     trace_qio_channel_socket_listen_sync(ioc, addr);
-    fd = socket_listen(addr, errp);
+    fd = socket_listen(addr, 1, errp);
     if (fd < 0) {
         trace_qio_channel_socket_listen_fail(ioc);
         return -1;

qga/channel-posix.c

@@ -215,7 +215,7 @@ static gboolean ga_channel_open(GAChannel *c, const gchar *path,
                 return false;
             }
 
-            fd = socket_listen(addr, &local_err);
+            fd = socket_listen(addr, 1, &local_err);
             qapi_free_SocketAddress(addr);
             if (local_err != NULL) {
                 g_critical("%s", error_get_pretty(local_err));

tests/test-util-sockets.c

@@ -93,7 +93,7 @@ static void test_socket_fd_pass_name_good(void)
     g_assert_cmpint(fd, !=, mon_fd);
     close(fd);
 
-    fd = socket_listen(&addr, &error_abort);
+    fd = socket_listen(&addr, 1, &error_abort);
     g_assert_cmpint(fd, !=, -1);
     g_assert_cmpint(fd, !=, mon_fd);
     close(fd);
@@ -124,7 +124,7 @@ static void test_socket_fd_pass_name_bad(void)
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
-    fd = socket_listen(&addr, &err);
+    fd = socket_listen(&addr, 1, &err);
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
@@ -151,7 +151,7 @@ static void test_socket_fd_pass_name_nomon(void)
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
-    fd = socket_listen(&addr, &err);
+    fd = socket_listen(&addr, 1, &err);
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
@@ -174,7 +174,7 @@ static void test_socket_fd_pass_num_good(void)
     fd = socket_connect(&addr, &error_abort);
     g_assert_cmpint(fd, ==, sfd);
 
-    fd = socket_listen(&addr, &error_abort);
+    fd = socket_listen(&addr, 1, &error_abort);
     g_assert_cmpint(fd, ==, sfd);
 
     g_free(addr.u.fd.str);
@@ -197,7 +197,7 @@ static void test_socket_fd_pass_num_bad(void)
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
-    fd = socket_listen(&addr, &err);
+    fd = socket_listen(&addr, 1, &err);
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
@@ -220,7 +220,7 @@ static void test_socket_fd_pass_num_nocli(void)
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
-    fd = socket_listen(&addr, &err);
+    fd = socket_listen(&addr, 1, &err);
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 

util/qemu-sockets.c

@@ -31,6 +31,7 @@
 #include "qapi/qobject-input-visitor.h"
 #include "qapi/qobject-output-visitor.h"
 #include "qemu/cutils.h"
+#include "trace.h"
 
 #ifndef AI_ADDRCONFIG
 # define AI_ADDRCONFIG 0
@@ -207,6 +208,7 @@ static int try_bind(int socket, InetSocketAddress *saddr, struct addrinfo *e)
 
 static int inet_listen_saddr(InetSocketAddress *saddr,
                              int port_offset,
+                             int num,
                              Error **errp)
 {
     struct addrinfo ai,*res,*e;
@@ -309,7 +311,7 @@ static int inet_listen_saddr(InetSocketAddress *saddr,
                     goto listen_failed;
                 }
             } else {
-                if (!listen(slisten, 1)) {
+                if (!listen(slisten, num)) {
                     goto listen_ok;
                 }
                 if (errno != EADDRINUSE) {
@@ -774,6 +776,7 @@ static int vsock_connect_saddr(VsockSocketAddress *vaddr, Error **errp)
 }
 
 static int vsock_listen_saddr(VsockSocketAddress *vaddr,
+                              int num,
                               Error **errp)
 {
     struct sockaddr_vm svm;
@@ -795,7 +798,7 @@ static int vsock_listen_saddr(VsockSocketAddress *vaddr,
         return -1;
     }
 
-    if (listen(slisten, 1) != 0) {
+    if (listen(slisten, num) != 0) {
         error_setg_errno(errp, errno, "Failed to listen on socket");
         closesocket(slisten);
         return -1;
@@ -836,6 +839,7 @@ static int vsock_connect_saddr(VsockSocketAddress *vaddr, Error **errp)
 }
 
 static int vsock_listen_saddr(VsockSocketAddress *vaddr,
+                              int num,
                               Error **errp)
 {
     vsock_unsupported(errp);
@@ -853,6 +857,7 @@ static int vsock_parse(VsockSocketAddress *addr, const char *str,
 #ifndef _WIN32
 
 static int unix_listen_saddr(UnixSocketAddress *saddr,
+                             int num,
                              Error **errp)
 {
     struct sockaddr_un un;
@@ -914,7 +919,7 @@ static int unix_listen_saddr(UnixSocketAddress *saddr,
         error_setg_errno(errp, errno, "Failed to bind socket to %s", path);
         goto err;
     }
-    if (listen(sock, 1) < 0) {
+    if (listen(sock, num) < 0) {
         error_setg_errno(errp, errno, "Failed to listen on socket");
         goto err;
     }
@@ -981,6 +986,7 @@ static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
 #else
 
 static int unix_listen_saddr(UnixSocketAddress *saddr,
+                             int num,
                              Error **errp)
 {
     error_setg(errp, "unix sockets are not available on windows");
@@ -1004,7 +1010,7 @@ int unix_listen(const char *str, Error **errp)
 
     saddr = g_new0(UnixSocketAddress, 1);
     saddr->path = g_strdup(str);
-    sock = unix_listen_saddr(saddr, errp);
+    sock = unix_listen_saddr(saddr, 1, errp);
     qapi_free_UnixSocketAddress(saddr);
     return sock;
 }
@@ -1061,9 +1067,13 @@ fail:
     return NULL;
 }
 
-static int socket_get_fd(const char *fdstr, Error **errp)
+static int socket_get_fd(const char *fdstr, int num, Error **errp)
 {
     int fd;
+    if (num != 1) {
+        error_setg_errno(errp, EINVAL, "socket_get_fd: too many connections");
+        return -1;
+    }
     if (cur_mon) {
         fd = monitor_get_fd(cur_mon, fdstr, errp);
         if (fd < 0) {
@@ -1099,7 +1109,7 @@ int socket_connect(SocketAddress *addr, Error **errp)
         break;
 
     case SOCKET_ADDRESS_TYPE_FD:
-        fd = socket_get_fd(addr->u.fd.str, errp);
+        fd = socket_get_fd(addr->u.fd.str, 1, errp);
         break;
 
     case SOCKET_ADDRESS_TYPE_VSOCK:
@@ -1112,25 +1122,26 @@ int socket_connect(SocketAddress *addr, Error **errp)
     return fd;
 }
 
-int socket_listen(SocketAddress *addr, Error **errp)
+int socket_listen(SocketAddress *addr, int num, Error **errp)
 {
     int fd;
 
+    trace_socket_listen(num);
     switch (addr->type) {
     case SOCKET_ADDRESS_TYPE_INET:
-        fd = inet_listen_saddr(&addr->u.inet, 0, errp);
+        fd = inet_listen_saddr(&addr->u.inet, 0, num, errp);
         break;
 
     case SOCKET_ADDRESS_TYPE_UNIX:
-        fd = unix_listen_saddr(&addr->u.q_unix, errp);
+        fd = unix_listen_saddr(&addr->u.q_unix, num, errp);
         break;
 
     case SOCKET_ADDRESS_TYPE_FD:
-        fd = socket_get_fd(addr->u.fd.str, errp);
+        fd = socket_get_fd(addr->u.fd.str, num, errp);
         break;
 
     case SOCKET_ADDRESS_TYPE_VSOCK:
-        fd = vsock_listen_saddr(&addr->u.vsock, errp);
+        fd = vsock_listen_saddr(&addr->u.vsock, num, errp);
         break;
 
     default:

util/trace-events

@@ -64,6 +64,9 @@ lockcnt_futex_wait(const void *lockcnt, int val) "lockcnt %p waiting on %d"
 lockcnt_futex_wait_resume(const void *lockcnt, int new) "lockcnt %p after wait: %d"
 lockcnt_futex_wake(const void *lockcnt) "lockcnt %p waking up one waiter"
 
+# qemu-sockets.c
+socket_listen(int num) "backlog: %d"
+
 # qemu-thread-common.h
 qemu_mutex_lock(void *mutex, const char *file, const int line) "waiting on mutex %p (%s:%d)"
 qemu_mutex_locked(void *mutex, const char *file, const int line) "taken mutex %p (%s:%d)"