[ovs-dev] [InBandOVSDB 3/4] socket-util: Factor out new function inet_parse_active().

[Ben Pfaff]

An upcoming commit needs to parse connection strings without connecting to
them, so this change enables that.
---
 lib/socket-util.c |   81 ++++++++++++++++++++++++++++++++++-------------------
 lib/socket-util.h |    2 +
 2 files changed, 54 insertions(+), 29 deletions(-)

diff --git a/lib/socket-util.c b/lib/socket-util.c
index 912c47e..d194cab 100644
--- a/lib/socket-util.c
+++ b/lib/socket-util.c
@@ -292,55 +292,79 @@ guess_netmask(uint32_t ip)
             : htonl(0));                          /* ??? */
 }
 
-/* Opens a non-blocking IPv4 socket of the specified 'style' and connects to
- * 'target', which should be a string in the format "<host>[:<port>]".  <host>
- * is required.  If 'default_port' is nonzero then <port> is optional and
- * defaults to 'default_port'.
- *
- * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP).
- *
- * On success, returns 0 (indicating connection complete) or EAGAIN (indicating
- * connection in progress), in which case the new file descriptor is stored
- * into '*fdp'.  On failure, returns a positive errno value other than EAGAIN
- * and stores -1 into '*fdp'.
+/* Parses 'target', which should be a string in the format "<host>[:<port>]".
+ * <host> is required.  If 'default_port' is nonzero then <port> is optional
+ * and defaults to 'default_port'.
  *
- * If 'sinp' is non-null, then on success the target address is stored into
- * '*sinp'. */
-int
-inet_open_active(int style, const char *target_, uint16_t default_port,
-                 struct sockaddr_in *sinp, int *fdp)
+ * On success, returns true and stores the parsed remote address into '*sinp'.
+ * On failure, logs an error and returns false. */
+bool
+inet_parse_active(const char *target_, uint16_t default_port,
+                  struct sockaddr_in *sinp)
 {
     char *target = xstrdup(target_);
     char *save_ptr = NULL;
     const char *host_name;
     const char *port_string;
-    struct sockaddr_in sin;
-    int fd = -1;
-    int error;
+    bool ok = false;
 
     /* Defaults. */
-    memset(&sin, 0, sizeof sin);
-    sin.sin_family = AF_INET;
-    sin.sin_port = htons(default_port);
+    sinp->sin_family = AF_INET;
+    sinp->sin_port = htons(default_port);
 
     /* Tokenize. */
     host_name = strtok_r(target, ":", &save_ptr);
     port_string = strtok_r(NULL, ":", &save_ptr);
     if (!host_name) {
-        ovs_error(0, "%s: bad peer name format", target_);
-        error = EAFNOSUPPORT;
+        VLOG_ERR("%s: bad peer name format", target_);
         goto exit;
     }
 
     /* Look up IP, port. */
-    error = lookup_ip(host_name, &sin.sin_addr);
-    if (error) {
+    if (lookup_ip(host_name, &sinp->sin_addr)) {
         goto exit;
     }
     if (port_string && atoi(port_string)) {
-        sin.sin_port = htons(atoi(port_string));
+        sinp->sin_port = htons(atoi(port_string));
     } else if (!default_port) {
         VLOG_ERR("%s: port number must be specified", target_);
+        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' and connects to
+ * 'target', which should be a string in the format "<host>[:<port>]".  <host>
+ * is required.  If 'default_port' is nonzero then <port> is optional and
+ * defaults to 'default_port'.
+ *
+ * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP).
+ *
+ * On success, returns 0 (indicating connection complete) or EAGAIN (indicating
+ * connection in progress), in which case the new file descriptor is stored
+ * into '*fdp'.  On failure, returns a positive errno value other than EAGAIN
+ * and stores -1 into '*fdp'.
+ *
+ * If 'sinp' is non-null, then on success the target address is stored into
+ * '*sinp'. */
+int
+inet_open_active(int style, const char *target, uint16_t default_port,
+                 struct sockaddr_in *sinp, int *fdp)
+{
+    struct sockaddr_in sin;
+    int fd = -1;
+    int error;
+
+    /* Parse. */
+    if (!inet_parse_active(target, default_port, &sin)) {
         error = EAFNOSUPPORT;
         goto exit;
     }
@@ -348,7 +372,7 @@ inet_open_active(int style, const char *target_, uint16_t default_port,
     /* Create non-blocking socket. */
     fd = socket(AF_INET, style, 0);
     if (fd < 0) {
-        VLOG_ERR("%s: socket: %s", target_, strerror(errno));
+        VLOG_ERR("%s: socket: %s", target, strerror(errno));
         error = errno;
         goto exit;
     }
@@ -379,7 +403,6 @@ exit:
     } else {
         *fdp = -1;
     }
-    free(target);
     return error;
 }
 
diff --git a/lib/socket-util.h b/lib/socket-util.h
index e489926..f5d6010 100644
--- a/lib/socket-util.h
+++ b/lib/socket-util.h
@@ -34,6 +34,8 @@ int get_unix_name_len(socklen_t sun_len);
 uint32_t guess_netmask(uint32_t ip);
 int get_null_fd(void);
 
+bool inet_parse_active(const char *target, uint16_t default_port,
+                       struct sockaddr_in *sinp);
 int inet_open_active(int style, const char *target, uint16_t default_port,
                     struct sockaddr_in *sinp, int *fdp);
 int inet_open_passive(int style, const char *target, int default_port,
-- 
1.6.6.1