From e2ac1a1b4c0f2b2674bf69a1ef0ee94dd4c404b0 Mon Sep 17 00:00:00 2001
From: Max <msuraev@sysmocom.de>
Date: Thu, 8 Sep 2022 18:45:07 +0700
Subject: [PATCH] Update multiaddr helper

* use osmo_strbuf instead of plain buffer
* properly handle OOM
* fix missing trailing ')'

Related: OS#5581
Change-Id: Icef53fe4b6e51563d97a1bc48001d67679b3b6e9
---
 src/socket.c | 65 ++++++++++++++++++++++++++++++++++------------------
 1 file changed, 43 insertions(+), 22 deletions(-)

diff --git a/src/socket.c b/src/socket.c
index 4605db4c0..77d0901a6 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -202,37 +202,57 @@ static int socket_helper_osa(const struct osmo_sockaddr *addr, uint16_t type, ui
 }
 
 #ifdef HAVE_LIBSCTP
-/* Fill buf with a string representation of the address set, in the form:
+/* Fill osmo_strbuf with a string representation of the address set, in the form:
  * buf_len == 0: "()"
  * buf_len == 1: "hostA"
  * buf_len >= 2: (hostA|hostB|...|...)
  */
-static int multiaddr_snprintf(char* buf, size_t buf_len, const char **hosts, size_t host_cnt)
+static int multiaddr_strbuf(struct osmo_strbuf *sb,
+				const char **hosts, size_t host_count,
+				struct sockaddr **addrs, size_t addrs_count)
 {
-	int len = 0, offset = 0, rem = buf_len;
-	size_t i;
-	int ret;
+	bool use_hosts = hosts ? true : false;
+	size_t i, count = use_hosts ? host_count : addrs_count;
+	struct osmo_sockaddr_str t;
+	struct osmo_sockaddr_str *oss = &t;
 	char *after;
+	int rc;
 
-	if (buf_len < 3)
-		return -EINVAL;
+	if (sb->len < 3)
+		return -ENOMEM;
 
-	if (host_cnt != 1) {
-		ret = snprintf(buf, rem, "(");
-		if (ret < 0)
-			return ret;
-		OSMO_SNPRINTF_RET(ret, rem, offset, len);
-	}
-	for (i = 0; i < host_cnt; i++) {
-		if (host_cnt == 1)
+	if (count != 1)
+		OSMO_STRBUF_PRINTF(*sb, "(");
+
+	for (i = 0; i < count; i++) {
+		const struct sockaddr *addr = &(*addrs)[i];
+
+		if (count == 1)
 			after = "";
 		else
-			after = (i == (host_cnt - 1)) ? ")" : "|";
-		ret = snprintf(buf + offset, rem, "%s%s", hosts[i] ? : "0.0.0.0", after);
-		OSMO_SNPRINTF_RET(ret, rem, offset, len);
+			after = (i == (count - 1)) ? ")" : "|";
+
+		if (use_hosts) {
+			if (hosts[i])
+				OSMO_STRBUF_PRINTF(*sb, "%s%s", hosts[i], after);
+		} else {
+			rc = osmo_sockaddr_str_from_sockaddr(oss, (const struct sockaddr_storage *)addr);
+			if (rc < 0) {
+				LOGP(DLGLOBAL, LOGL_DEBUG, "Conversion failure in multiaddr_strbuf(): %s\n", strerror(-rc));
+				return rc;
+			}
+			OSMO_STRBUF_PRINTF(*sb, OSMO_SOCKADDR_STR_NO_PORT_FMT "%s",
+						OSMO_SOCKADDR_STR_NO_PORT_FMT_ARGS(oss), after);
+		}
 	}
 
-	return len;
+	if (count == 0)
+		OSMO_STRBUF_PRINTF(*sb, ")");
+
+	if (sb->chars_needed >= sb->len)
+		return -ENOSPC;
+
+	return sb->chars_needed;
 }
 #endif /* HAVE_LIBSCTP */
 
@@ -726,6 +746,7 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 	bool loc_has_v6addr, rem_has_v6addr;
 	struct sockaddr_in6 addrs_buf[OSMO_SOCK_MAX_ADDRS];
 	char strbuf[512];
+	struct osmo_strbuf sb = { .buf = strbuf, .len = 512 };
 
 	/* updated later in case of AF_UNSPEC */
 	loc_has_v4addr = rem_has_v4addr = (family == AF_INET);
@@ -794,7 +815,7 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 		rc = setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR,
 				&on, sizeof(on));
 		if (rc < 0) {
-			multiaddr_snprintf(strbuf, sizeof(strbuf), local_hosts, local_hosts_cnt);
+			multiaddr_strbuf(&sb, local_hosts, local_hosts_cnt, NULL, 0);
 			LOGP(DLGLOBAL, LOGL_ERROR,
 			     "cannot setsockopt socket:"
 			     " %s:%u: %s\n",
@@ -817,7 +838,7 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 
 		rc = sctp_bindx(sfd, (struct sockaddr *)addrs_buf, local_hosts_cnt, SCTP_BINDX_ADD_ADDR);
 		if (rc == -1) {
-			multiaddr_snprintf(strbuf, sizeof(strbuf), local_hosts, local_hosts_cnt);
+			multiaddr_strbuf(&sb, local_hosts, local_hosts_cnt, NULL, 0);
 			LOGP(DLGLOBAL, LOGL_NOTICE, "unable to bind socket: %s:%u: %s\n",
 			     strbuf, local_port, strerror(errno));
 			rc = -ENODEV;
@@ -839,7 +860,7 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 
 		rc = sctp_connectx(sfd, (struct sockaddr *)addrs_buf, remote_hosts_cnt, NULL);
 		if (rc != 0 && errno != EINPROGRESS) {
-			multiaddr_snprintf(strbuf, sizeof(strbuf), remote_hosts, remote_hosts_cnt);
+			multiaddr_strbuf(&sb, remote_hosts, remote_hosts_cnt, NULL, 0);
 			LOGP(DLGLOBAL, LOGL_ERROR, "unable to connect socket: %s:%u: %s\n",
 				strbuf, remote_port, strerror(errno));
 			rc = -ENODEV;