X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fsocket-util.c;h=d8ae179b357741e99e55d607df0de8af37458e8e;hb=0afaa4516c3308b6734b99914ceba3cd266d3332;hp=91cdc1d6829c1b663e52ead3b71b9d86f1038475;hpb=be25fa83e8f65d92b853bd20a3d1a594af352b92;p=sliver-openvswitch.git

diff --git a/lib/socket-util.c b/lib/socket-util.c
index 91cdc1d68..d8ae179b3 100644
--- a/lib/socket-util.c
+++ b/lib/socket-util.c
@@ -38,8 +38,14 @@
 #include <fcntl.h>
 #include <netdb.h>
 #include <poll.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <string.h>
+#include <sys/resource.h>
+#include <sys/un.h>
+#include <unistd.h>
+#include "fatal-signal.h"
+#include "util.h"
 
 #include "vlog.h"
 #define THIS_MODULE VLM_socket_util
@@ -63,6 +69,26 @@ set_nonblocking(int fd)
     }
 }
 
+/* Returns the maximum valid FD value, plus 1. */
+int
+get_max_fds(void)
+{
+    static int max_fds = -1;
+    if (max_fds < 0) {
+        struct rlimit r;
+        if (!getrlimit(RLIMIT_NOFILE, &r)
+            && r.rlim_cur != RLIM_INFINITY
+            && r.rlim_cur != RLIM_SAVED_MAX
+            && r.rlim_cur != RLIM_SAVED_CUR) {
+            max_fds = r.rlim_cur;
+        } else {
+            VLOG_WARN("failed to obtain fd limit, defaulting to 1024");
+            max_fds = 1024;
+        }
+    }
+    return max_fds;
+}
+
 /* Translates 'host_name', which may be a DNS name or an IP address, into a
  * numeric IP address in '*addr'.  Returns 0 if successful, otherwise a
  * positive errno value. */
@@ -72,12 +98,13 @@ lookup_ip(const char *host_name, struct in_addr *addr)
     if (!inet_aton(host_name, addr)) {
         struct hostent *he = gethostbyname(host_name);
         if (he == NULL) {
-            VLOG_ERR("gethostbyname(%s): %s", host_name,
-                     (h_errno == HOST_NOT_FOUND ? "host not found"
-                      : h_errno == TRY_AGAIN ? "try again"
-                      : h_errno == NO_RECOVERY ? "non-recoverable error"
-                      : h_errno == NO_ADDRESS ? "no address"
-                      : "unknown error"));
+            struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
+            VLOG_ERR_RL(&rl, "gethostbyname(%s): %s", host_name,
+                        (h_errno == HOST_NOT_FOUND ? "host not found"
+                         : h_errno == TRY_AGAIN ? "try again"
+                         : h_errno == NO_RECOVERY ? "non-recoverable error"
+                         : h_errno == NO_ADDRESS ? "no address"
+                         : "unknown error"));
             return ENOENT;
         }
         addr->s_addr = *(uint32_t *) he->h_addr;
@@ -93,8 +120,9 @@ get_socket_error(int fd)
     int error;
     socklen_t len = sizeof(error);
     if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &error, &len) < 0) {
+        struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10);
         error = errno;
-        VLOG_ERR("getsockopt(SO_ERROR): %s", strerror(error));
+        VLOG_ERR_RL(&rl, "getsockopt(SO_ERROR): %s", strerror(error));
     }
     return error;
 }
@@ -113,7 +141,8 @@ check_connection_completion(int fd)
     if (retval == 1) {
         return get_socket_error(fd);
     } else if (retval < 0) {
-        VLOG_ERR("poll: %s", strerror(errno));
+        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10);
+        VLOG_ERR_RL(&rl, "poll: %s", strerror(errno));
         return errno;
     } else {
         return EAGAIN;
@@ -133,7 +162,8 @@ drain_rcvbuf(int fd)
 
     rcvbuf_len = sizeof rcvbuf;
     if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, &rcvbuf_len) < 0) {
-        VLOG_ERR("getsockopt(SO_RCVBUF) failed: %s", strerror(errno));
+        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10);
+        VLOG_ERR_RL(&rl, "getsockopt(SO_RCVBUF) failed: %s", strerror(errno));
         return errno;
     }
     while (rcvbuf > 0) {
@@ -160,3 +190,118 @@ drain_rcvbuf(int fd)
     }
     return 0;
 }
+
+/* Reads and discards up to 'n' datagrams from 'fd', stopping as soon as no
+ * more data can be immediately read.  ('fd' should therefore be in
+ * non-blocking mode.)*/
+void
+drain_fd(int fd, size_t n_packets)
+{
+    for (; n_packets > 0; n_packets--) {
+        /* 'buffer' only needs to be 1 byte long in most circumstances.  This
+         * size is defensive against the possibility that we someday want to
+         * use a Linux tap device without TUN_NO_PI, in which case a buffer
+         * smaller than sizeof(struct tun_pi) will give EINVAL on read. */
+        char buffer[128];
+        if (read(fd, buffer, sizeof buffer) <= 0) {
+            break;
+        }
+    }
+}
+
+/* Stores in '*un' a sockaddr_un that refers to file 'name'.  Stores in
+ * '*un_len' the size of the sockaddr_un. */
+static void
+make_sockaddr_un(const char *name, struct sockaddr_un* un, socklen_t *un_len)
+{
+    un->sun_family = AF_UNIX;
+    strncpy(un->sun_path, name, sizeof un->sun_path);
+    un->sun_path[sizeof un->sun_path - 1] = '\0';
+    *un_len = (offsetof(struct sockaddr_un, sun_path)
+                + strlen (un->sun_path) + 1);
+}
+
+/* Creates a Unix domain socket in the given 'style' (either SOCK_DGRAM or
+ * SOCK_STREAM) that is bound to '*bind_path' (if 'bind_path' is non-null) and
+ * connected to '*connect_path' (if 'connect_path' is non-null).  If 'nonblock'
+ * is true, the socket is made non-blocking.  If 'passcred' is true, the socket
+ * is configured to receive SCM_CREDENTIALS control messages.
+ *
+ * Returns the socket's fd if successful, otherwise a negative errno value. */
+int
+make_unix_socket(int style, bool nonblock, bool passcred UNUSED,
+                 const char *bind_path, const char *connect_path)
+{
+    int error;
+    int fd;
+
+    fd = socket(PF_UNIX, style, 0);
+    if (fd < 0) {
+        return -errno;
+    }
+
+    /* Set nonblocking mode right away, if we want it.  This prevents blocking
+     * in connect(), if connect_path != NULL.  (In turn, that's a corner case:
+     * it will only happen if style is SOCK_STREAM or SOCK_SEQPACKET, and only
+     * if a backlog of un-accepted connections has built up in the kernel.)  */
+    if (nonblock) {
+        int flags = fcntl(fd, F_GETFL, 0);
+        if (flags == -1) {
+            goto error;
+        }
+        if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
+            goto error;
+        }
+    }
+
+    if (bind_path) {
+        struct sockaddr_un un;
+        socklen_t un_len;
+        make_sockaddr_un(bind_path, &un, &un_len);
+        if (unlink(un.sun_path) && errno != ENOENT) {
+            VLOG_WARN("unlinking \"%s\": %s\n", un.sun_path, strerror(errno));
+        }
+        fatal_signal_add_file_to_unlink(bind_path);
+        if (bind(fd, (struct sockaddr*) &un, un_len)
+            || fchmod(fd, S_IRWXU)) {
+            goto error;
+        }
+    }
+
+    if (connect_path) {
+        struct sockaddr_un un;
+        socklen_t un_len;
+        make_sockaddr_un(connect_path, &un, &un_len);
+        if (connect(fd, (struct sockaddr*) &un, un_len)
+            && errno != EINPROGRESS) {
+            goto error;
+        }
+    }
+
+#ifdef SCM_CREDENTIALS
+    if (passcred) {
+        int enable = 1;
+        if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(enable))) {
+            goto error;
+        }
+    }
+#endif
+
+    return fd;
+
+error:
+    if (bind_path) {
+        fatal_signal_remove_file_to_unlink(bind_path);
+    }
+    error = errno;
+    close(fd);
+    return -error;
+}
+
+int
+get_unix_name_len(socklen_t sun_len)
+{
+    return (sun_len >= offsetof(struct sockaddr_un, sun_path)
+            ? sun_len - offsetof(struct sockaddr_un, sun_path)
+            : 0);
+}