X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fsocket-util.c;h=c436724cd501f44f701bb53e33046af20ffaddeb;hb=1f00acd0bccc883f5b2017dc52f8f1d52a089b1f;hp=8ef63a7a0ff2ccfbae2043fa4d7e6a414aaa4fed;hpb=f89ffb0e2f6fa8adc100192ea4b5f948170d8d57;p=openvswitch

diff --git a/lib/socket-util.c b/lib/socket-util.c
index 8ef63a7a..c436724c 100644
--- a/lib/socket-util.c
+++ b/lib/socket-util.c
@@ -145,6 +145,37 @@ lookup_ipv6(const char *host_name, struct in6_addr *addr)
     return 0;
 }
 
+/* Translates 'host_name', which must be a host name or a string representation
+ * of an IP address, into a numeric IP address in '*addr'.  Returns 0 if
+ * successful, otherwise a positive errno value.
+ *
+ * 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
+ * this but it doesn't seem worthwhile quite yet.)  */
+int
+lookup_hostname(const char *host_name, struct in_addr *addr)
+{
+    struct hostent *h;
+
+    if (inet_aton(host_name, addr)) {
+        return 0;
+    }
+
+    h = gethostbyname(host_name);
+    if (h) {
+        *addr = *(struct in_addr *) h->h_addr;
+        return 0;
+    }
+
+    return (h_errno == HOST_NOT_FOUND ? ENOENT
+            : h_errno == TRY_AGAIN ? EAGAIN
+            : h_errno == NO_RECOVERY ? EIO
+            : h_errno == NO_ADDRESS ? ENXIO
+            : EINVAL);
+}
+
 /* Returns the error condition associated with socket 'fd' and resets the
  * socket's error status. */
 int
@@ -430,10 +461,10 @@ get_unix_name_len(socklen_t sun_len)
             : 0);
 }
 
-uint32_t
-guess_netmask(uint32_t ip)
+ovs_be32
+guess_netmask(ovs_be32 ip_)
 {
-    ip = ntohl(ip);
+    uint32_t ip = ntohl(ip_);
     return ((ip >> 31) == 0 ? htonl(0xff000000)   /* Class A */
             : (ip >> 30) == 2 ? htonl(0xffff0000) /* Class B */
             : (ip >> 29) == 6 ? htonl(0xffffff00) /* Class C */
@@ -554,9 +585,7 @@ exit:
     return error;
 }
 
-/* Opens a non-blocking IPv4 socket of the specified 'style', binds to
- * 'target', and listens for incoming connections.  'target' should be a string
- * in the format "[<port>][:<ip>]":
+/* Parses 'target', which should be a string in the format "[<port>][:<ip>]":
  *
  *      - If 'default_port' is -1, then <port> is required.  Otherwise, if
  *        <port> is omitted, then 'default_port' is used instead.
@@ -566,106 +595,127 @@ exit:
  *
  *      - If <ip> is omitted then the IP address is wildcarded.
  *
- * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP).
- *
- * For TCP, the socket will have SO_REUSEADDR turned on.
- *
- * On success, returns a non-negative file descriptor.  On failure, returns a
- * negative errno value.
- *
- * If 'sinp' is non-null, then on success the bound address is stored into
- * '*sinp'. */
-int
-inet_open_passive(int style, const char *target_, int default_port,
-                  struct sockaddr_in *sinp)
+ * If successful, stores the address into '*sinp' and returns true; otherwise
+ * zeros '*sinp' and returns false. */
+bool
+inet_parse_passive(const char *target_, uint16_t default_port,
+                   struct sockaddr_in *sinp)
 {
     char *target = xstrdup(target_);
     char *string_ptr = target;
-    struct sockaddr_in sin;
     const char *host_name;
     const char *port_string;
-    int fd = 0, error, port;
-    unsigned int yes  = 1;
+    bool ok = false;
+    int port;
 
     /* Address defaults. */
-    memset(&sin, 0, sizeof sin);
-    sin.sin_family = AF_INET;
-    sin.sin_addr.s_addr = htonl(INADDR_ANY);
-    sin.sin_port = htons(default_port);
+    memset(sinp, 0, sizeof *sinp);
+    sinp->sin_family = AF_INET;
+    sinp->sin_addr.s_addr = htonl(INADDR_ANY);
+    sinp->sin_port = htons(default_port);
 
     /* Parse optional port number. */
     port_string = strsep(&string_ptr, ":");
     if (port_string && str_to_int(port_string, 10, &port)) {
-        sin.sin_port = htons(port);
+        sinp->sin_port = htons(port);
     } else if (default_port < 0) {
         VLOG_ERR("%s: port number must be specified", target_);
-        error = EAFNOSUPPORT;
         goto exit;
     }
 
     /* Parse optional bind IP. */
     host_name = strsep(&string_ptr, ":");
-    if (host_name && host_name[0]) {
-        error = lookup_ip(host_name, &sin.sin_addr);
-        if (error) {
-            goto exit;
-        }
+    if (host_name && host_name[0] && lookup_ip(host_name, &sinp->sin_addr)) {
+        goto exit;
+    }
+
+    ok = true;
+
+exit:
+    if (!ok) {
+        memset(sinp, 0, sizeof *sinp);
+    }
+    free(target);
+    return ok;
+}
+
+
+/* Opens a non-blocking IPv4 socket of the specified 'style', binds to
+ * 'target', and listens for incoming connections.  Parses 'target' in the same
+ * way was inet_parse_passive().
+ *
+ * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP).
+ *
+ * For TCP, the socket will have SO_REUSEADDR turned on.
+ *
+ * On success, returns a non-negative file descriptor.  On failure, returns a
+ * negative errno value.
+ *
+ * If 'sinp' is non-null, then on success the bound address is stored into
+ * '*sinp'. */
+int
+inet_open_passive(int style, const char *target, int default_port,
+                  struct sockaddr_in *sinp)
+{
+    struct sockaddr_in sin;
+    int fd = 0, error;
+    unsigned int yes = 1;
+
+    if (!inet_parse_passive(target, default_port, &sin)) {
+        return EAFNOSUPPORT;
     }
 
     /* Create non-blocking socket, set SO_REUSEADDR. */
     fd = socket(AF_INET, style, 0);
     if (fd < 0) {
         error = errno;
-        VLOG_ERR("%s: socket: %s", target_, strerror(error));
-        goto exit;
+        VLOG_ERR("%s: socket: %s", target, strerror(error));
+        return error;
     }
     error = set_nonblocking(fd);
     if (error) {
-        goto exit_close;
+        goto error;
     }
     if (style == SOCK_STREAM
         && setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes) < 0) {
         error = errno;
-        VLOG_ERR("%s: setsockopt(SO_REUSEADDR): %s", target_, strerror(error));
-        goto exit_close;
+        VLOG_ERR("%s: setsockopt(SO_REUSEADDR): %s", target, strerror(error));
+        goto error;
     }
 
     /* Bind. */
     if (bind(fd, (struct sockaddr *) &sin, sizeof sin) < 0) {
         error = errno;
-        VLOG_ERR("%s: bind: %s", target_, strerror(error));
-        goto exit_close;
+        VLOG_ERR("%s: bind: %s", target, strerror(error));
+        goto error;
     }
 
     /* Listen. */
     if (listen(fd, 10) < 0) {
         error = errno;
-        VLOG_ERR("%s: listen: %s", target_, strerror(error));
-        goto exit_close;
+        VLOG_ERR("%s: listen: %s", target, strerror(error));
+        goto error;
     }
 
     if (sinp) {
         socklen_t sin_len = sizeof sin;
         if (getsockname(fd, (struct sockaddr *) &sin, &sin_len) < 0){
             error = errno;
-            VLOG_ERR("%s: getsockname: %s", target_, strerror(error));
-            goto exit_close;
+            VLOG_ERR("%s: getsockname: %s", target, strerror(error));
+            goto error;
         }
         if (sin.sin_family != AF_INET || sin_len != sizeof sin) {
-            VLOG_ERR("%s: getsockname: invalid socket name", target_);
-            goto exit_close;
+            VLOG_ERR("%s: getsockname: invalid socket name", target);
+            goto error;
         }
         *sinp = sin;
     }
 
-    error = 0;
-    goto exit;
+    return fd;
 
-exit_close:
+error:
     close(fd);
-exit:
-    free(target);
-    return error ? -error : fd;
+    return error;
 }
 
 /* Returns a readable and writable fd for /dev/null, if successful, otherwise