socket-util: Avoid using SO_ERROR.

[openvswitch] / lib / socket-util.c

diff --git a/lib/socket-util.c b/lib/socket-util.c
index 5fe9f98ba2fd9bc2c71793891f9a2fa876fbc503..4843cc5423f1384cdc7eb7357f86f1dbd87170c8 100644 (file)
--- a/lib/socket-util.c
+++ b/lib/socket-util.c
@@ -30,6 +30,7 @@
 #include <sys/resource.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
+#include <sys/uio.h>
 #include <sys/un.h>
 #include <unistd.h>
 #include "dynamic-string.h"
@@ -38,7 +39,7 @@
 #include "poll-loop.h"
 #include "util.h"
 #include "vlog.h"
-#if AF_PACKET && __linux__
+#if AF_PACKET && LINUX_DATAPATH
 #include <linux/if_packet.h>
 #endif
 #ifdef HAVE_NETLINK
@@ -50,11 +51,9 @@ VLOG_DEFINE_THIS_MODULE(socket_util);
 
 /* #ifdefs make it a pain to maintain code: you have to try to build both ways.
  * Thus, this file compiles all of the code regardless of the target, by
- * writing "if (LINUX)" instead of "#ifdef __linux__". */
-#ifdef __linux__
-#define LINUX 1
-#else
-#define LINUX 0
+ * writing "if (LINUX_DATAPATH)" instead of "#ifdef __linux__". */
+#ifndef LINUX_DATAPATH
+#define LINUX_DATAPATH 0
 #endif
 
 #ifndef O_DIRECTORY
@@ -91,15 +90,17 @@ xset_nonblocking(int fd)
     }
 }
 
-static int
+int
 set_dscp(int fd, uint8_t dscp)
 {
+    int val;
+
     if (dscp > 63) {
         return EINVAL;
     }
 
-    dscp = dscp << 2;
-    if (setsockopt(fd, IPPROTO_IP, IP_TOS, &dscp, sizeof dscp)) {
+    val = dscp << 2;
+    if (setsockopt(fd, IPPROTO_IP, IP_TOS, &val, sizeof val)) {
         return errno;
     }
 
@@ -180,7 +181,7 @@ lookup_ipv6(const char *host_name, struct in6_addr *addr)
  * Most Open vSwitch code should not use this because it causes deadlocks:
  * gethostbyname() sends out a DNS request but that starts a new flow for which
  * OVS must set up a flow, but it can't because it's waiting for a DNS reply.
- * The synchronous lookup also delays other activty.  (Of course we can solve
+ * The synchronous lookup also delays other activity.  (Of course we can solve
  * this but it doesn't seem worthwhile quite yet.)  */
 int
 lookup_hostname(const char *host_name, struct in_addr *addr)
@@ -220,6 +221,7 @@ get_socket_error(int fd)
 int
 check_connection_completion(int fd)
 {
+    static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10);
     struct pollfd pfd;
     int retval;
 
@@ -229,9 +231,17 @@ check_connection_completion(int fd)
         retval = poll(&pfd, 1, 0);
     } while (retval < 0 && errno == EINTR);
     if (retval == 1) {
-        return get_socket_error(fd);
+        if (pfd.revents & POLLERR) {
+            ssize_t n = send(fd, "", 1, MSG_DONTWAIT);
+            if (n < 0) {
+                return errno;
+            } else {
+                VLOG_ERR_RL(&rl, "poll return POLLERR but send succeeded");
+                return EPROTO;
+            }
+        }
+        return 0;
     } else if (retval < 0) {
-        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10);
         VLOG_ERR_RL(&rl, "poll: %s", strerror(errno));
         return errno;
     } else {
@@ -263,7 +273,7 @@ drain_rcvbuf(int fd)
          *
          * On other Unix-like OSes, MSG_TRUNC has no effect in the flags
          * argument. */
-        char buffer[LINUX ? 1 : 2048];
+        char buffer[LINUX_DATAPATH ? 1 : 2048];
         ssize_t n_bytes = recv(fd, buffer, sizeof buffer,
                                MSG_TRUNC | MSG_DONTWAIT);
         if (n_bytes <= 0 || n_bytes >= rcvbuf) {
@@ -332,7 +342,7 @@ make_sockaddr_un(const char *name, struct sockaddr_un *un, socklen_t *un_len,
     if (strlen(name) > MAX_UN_LEN) {
         static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
 
-        if (LINUX) {
+        if (LINUX_DATAPATH) {
             /* 'name' is too long to fit in a sockaddr_un, but we have a
              * workaround for that on Linux: shorten it by opening a file
              * descriptor for the directory part of the name and indirecting
@@ -611,6 +621,7 @@ exit:
         }
     } else if (fd >= 0) {
         close(fd);
+        fd = -1;
     }
     *fdp = fd;
     return error;
@@ -890,6 +901,14 @@ xpipe(int fds[2])
     }
 }
 
+void
+xpipe_nonblocking(int fds[2])
+{
+    xpipe(fds);
+    xset_nonblocking(fds[0]);
+    xset_nonblocking(fds[1]);
+}
+
 void
 xsocketpair(int domain, int type, int protocol, int fds[2])
 {
@@ -977,7 +996,7 @@ describe_sockaddr(struct ds *string, int fd,
             }
         }
 #endif
-#if AF_PACKET && __linux__
+#if AF_PACKET && LINUX_DATAPATH
         else if (ss.ss_family == AF_PACKET) {
             struct sockaddr_ll sll;
 
@@ -1007,7 +1026,7 @@ describe_sockaddr(struct ds *string, int fd,
 }
 
 
-#ifdef __linux__
+#ifdef LINUX_DATAPATH
 static void
 put_fd_filename(struct ds *string, int fd)
 {
@@ -1051,7 +1070,7 @@ describe_fd(int fd)
                               : S_ISFIFO(s.st_mode) ? "FIFO"
                               : S_ISLNK(s.st_mode) ? "symbolic link"
                               : "unknown"));
-#ifdef __linux__
+#ifdef LINUX_DATAPATH
         put_fd_filename(&string, fd);
 #endif
     }