add osmo_sock_get_{local,remote}_ip{,_port}()

Return only the IP or port of either the local or remote connection,
not the whole set of IP and port of both the local and remote
connection like osmo_sock_get_name() does it. This is needed for
OS#2841, where we only want to print the remote IP.

Related: OS#2841
Change-Id: I6803c204771c59a2002bc6a0e6b79c83c35f87e1

1 files changed, 86 insertions, 25 deletions

diff --git a/src/socket.c b/src/socket.c
index bb5505f9..c7e1c9dd 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -682,44 +682,105 @@ int osmo_sock_unix_init_ofd(struct osmo_fd *ofd, uint16_t type, uint8_t proto,
 	return osmo_fd_init_ofd(ofd, osmo_sock_unix_init(type, proto, socket_path, flags));
 }
 
-/*! Get address/port information on socket in dyn-alloc string
- *  \param[in] ctx talloc context from which to allocate string buffer
+/*! Get the IP and/or port number on socket. This is for internal usage.
+ *  Convenience wrappers: osmo_sock_get_local_ip(),
+ *  osmo_sock_get_local_ip_port(), osmo_sock_get_remote_ip(),
+ *  osmo_sock_get_remote_ip_port() and osmo_sock_get_name()
  *  \param[in] fd file descriptor of socket
- *  \returns string identifying the connection of this socket
+ *  \param[out] ip IP address (will be filled in when not NULL)
+ *  \param[in] ip_len length of the ip buffer
+ *  \param[out] port number (will be filled in when not NULL)
+ *  \param[in] port_len length of the port buffer
+ *  \param[in] local (true) or remote (false) name will get looked at
+ *  \returns 0 on success; negative otherwise
  */
-char *osmo_sock_get_name(void *ctx, int fd)
+static int osmo_sock_get_name2(int fd, char *ip, size_t ip_len, char *port, size_t port_len, bool local)
 {
-	struct sockaddr sa_l, sa_r;
-	socklen_t sa_len_l = sizeof(sa_l);
-	socklen_t sa_len_r = sizeof(sa_r);
-	char hostbuf_l[64], hostbuf_r[64];
-	char portbuf_l[16], portbuf_r[16];
+	struct sockaddr sa;
+	socklen_t len = sizeof(sa);
+	char ipbuf[64], portbuf[16];
 	int rc;
 
-	rc = getsockname(fd, &sa_l, &sa_len_l);
+	rc = local ? getsockname(fd, &sa, &len) : getpeername(fd, &sa, &len);
 	if (rc < 0)
-		return NULL;
+		return rc;
 
-	rc = getnameinfo(&sa_l, sa_len_l, hostbuf_l, sizeof(hostbuf_l),
-			 portbuf_l, sizeof(portbuf_l),
+	rc = getnameinfo(&sa, len, ipbuf, sizeof(ipbuf),
+			 portbuf, sizeof(portbuf),
 			 NI_NUMERICHOST | NI_NUMERICSERV);
 	if (rc < 0)
-		return NULL;
+		return rc;
 
-	rc = getpeername(fd, &sa_r, &sa_len_r);
-	if (rc < 0)
-		goto local_only;
+	if (ip)
+		strncpy(ip, ipbuf, ip_len);
+	if (port)
+		strncpy(port, portbuf, port_len);
+	return 0;
+}
 
-	rc = getnameinfo(&sa_r, sa_len_r, hostbuf_r, sizeof(hostbuf_r),
-			 portbuf_r, sizeof(portbuf_r),
-			 NI_NUMERICHOST | NI_NUMERICSERV);
-	if (rc < 0)
-		goto local_only;
+/*! Get local IP address on socket
+ *  \param[in] fd file descriptor of socket
+ *  \param[out] ip IP address (will be filled in)
+ *  \param[in] len length of the output buffer
+ *  \returns 0 on success; negative otherwise
+ */
+int osmo_sock_get_local_ip(int fd, char *ip, size_t len)
+{
+	return osmo_sock_get_name2(fd, ip, len, NULL, 0, true);
+}
+
+/*! Get local port on socket
+ *  \param[in] fd file descriptor of socket
+ *  \param[out] port number (will be filled in)
+ *  \param[in] len length of the output buffer
+ *  \returns 0 on success; negative otherwise
+ */
+int osmo_sock_get_local_ip_port(int fd, char *port, size_t len)
+{
+	return osmo_sock_get_name2(fd, NULL, 0, port, len, true);
+}
+
+/*! Get remote IP address on socket
+ *  \param[in] fd file descriptor of socket
+ *  \param[out] ip IP address (will be filled in)
+ *  \param[in] len length of the output buffer
+ *  \returns 0 on success; negative otherwise
+ */
+int osmo_sock_get_remote_ip(int fd, char *ip, size_t len)
+{
+	return osmo_sock_get_name2(fd, ip, len, NULL, 0, false);
+}
+
+/*! Get remote port on socket
+ *  \param[in] fd file descriptor of socket
+ *  \param[out] port number (will be filled in)
+ *  \param[in] len length of the output buffer
+ *  \returns 0 on success; negative otherwise
+ */
+int osmo_sock_get_remote_ip_port(int fd, char *port, size_t len)
+{
+	return osmo_sock_get_name2(fd, NULL, 0, port, len, false);
+}
+
+/*! Get address/port information on socket in dyn-alloc string
+ *  \param[in] ctx talloc context from which to allocate string buffer
+ *  \param[in] fd file descriptor of socket
+ *  \returns string identifying the connection of this socket
+ */
+char *osmo_sock_get_name(void *ctx, int fd)
+{
+	char hostbuf_l[64], hostbuf_r[64];
+	char portbuf_l[16], portbuf_r[16];
+
+	/* get local */
+	if (osmo_sock_get_name2(fd, hostbuf_l, sizeof(hostbuf_l), portbuf_l, sizeof(portbuf_l), true))
+		return NULL;
 
-	return talloc_asprintf(ctx, "(r=%s:%s<->l=%s:%s)", hostbuf_r, portbuf_r,
-				hostbuf_l, portbuf_l);
+	/* get remote */
+	if (!osmo_sock_get_name2(fd, hostbuf_r, sizeof(hostbuf_r), portbuf_r, sizeof(portbuf_r), false))
+		return talloc_asprintf(ctx, "(r=%s:%s<->l=%s:%s)", hostbuf_r, portbuf_r, hostbuf_l, portbuf_l);
 
-local_only:
+	/* local only: different format */
 	return talloc_asprintf(ctx, "(r=NULL<->l=%s:%s)", hostbuf_l, portbuf_l);
 }