From 797f7528453766831585b81546422fa76969ff41 Mon Sep 17 00:00:00 2001
From: Nils Philippsen <nils@tiptoe.de>
Date: Mon, 13 Nov 2023 23:46:41 +0100
Subject: [PATCH] =?UTF-8?q?Don=E2=80=99t=20use=20gethostbyname()?=
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Use getaddrinfo() instead, which can do IPv6 and multiple addresses.

Signed-off-by: Nils Philippsen <nils@tiptoe.de>
---
 tools/netsource.c | 129 ++++++++++++++++++++++++++++++----------------
 1 file changed, 86 insertions(+), 43 deletions(-)

diff --git a/tools/netsource.c b/tools/netsource.c
index 401c403..a14d7fc 100644
--- a/tools/netsource.c
+++ b/tools/netsource.c
@@ -82,7 +82,7 @@ int mtu = 1400;
 int reply_port = 0;
 int bind_port = 0;
 int redundancy = 1;
-jack_client_t *client;
+jack_client_t *client = NULL;
 packet_cache * packcache = 0;
 
 int state_connected = 0;
@@ -96,13 +96,8 @@ int quit = 0;
 
 int outsockfd;
 int insockfd;
-#ifdef WIN32
-struct sockaddr_in destaddr;
-struct sockaddr_in bindaddr;
-#else
-struct sockaddr destaddr;
-struct sockaddr bindaddr;
-#endif
+struct addrinfo *destaddr = NULL;
+struct addrinfo *bindaddr;
 
 int sync_state;
 jack_transport_state_t last_transport_state;
@@ -475,27 +470,6 @@ jack_shutdown (void *arg)
     exit (1);
 }
 
-void
-init_sockaddr_in (struct sockaddr_in *name , const char *hostname , uint16_t port)
-{
-    name->sin_family = AF_INET ;
-    name->sin_port = htons (port);
-    if (hostname) {
-        struct hostent *hostinfo = gethostbyname (hostname);
-        if (hostinfo == NULL) {
-            fprintf (stderr, "init_sockaddr_in: unknown host: %s.\n", hostname);
-            fflush( stderr );
-        }
-#ifdef WIN32
-        name->sin_addr.s_addr = inet_addr( hostname );
-#else
-        name->sin_addr = *(struct in_addr *) hostinfo->h_addr ;
-#endif
-    } else
-        name->sin_addr.s_addr = htonl (INADDR_ANY) ;
-
-}
-
 void
 printUsage ()
 {
@@ -546,7 +520,8 @@ main (int argc, char *argv[])
     /* Argument parsing stuff */
     extern char *optarg;
     extern int optind, optopt;
-    int errflg = 0, c;
+    int errflg = 0, c, e, retval = 0;
+    struct addrinfo hints, *rp;
 
     if (argc < 3) {
         printUsage ();
@@ -641,25 +616,85 @@ main (int argc, char *argv[])
     capture_channels = capture_channels_audio + capture_channels_midi;
     playback_channels = playback_channels_audio + playback_channels_midi;
 
-    outsockfd = socket (AF_INET, SOCK_DGRAM, 0);
-    insockfd = socket (AF_INET, SOCK_DGRAM, 0);
-
     if ((outsockfd == -1) || (insockfd == -1)) {
         fprintf (stderr, "can not open sockets\n" );
         return 1;
     }
 
-    init_sockaddr_in ((struct sockaddr_in *) &destaddr, peer_ip, peer_port);
+    memset(&hints, '\0', sizeof(hints));
+    hints.ai_socktype = SOCK_STREAM;
+    hints.ai_flags = AI_ADDRCONFIG;
+
+    e = getaddrinfo (peer_ip, peer_port, &hints, &destaddr);
+    if (e) {
+        retval = 1;
+        fprintf (stderr, "getaddrinfo(\"%s\", \"%s\", ...) failed: %s\n", peer_ip, peer_port, gai_strerror (e));
+        goto cleanup;
+    }
+
     if (bind_port) {
-        init_sockaddr_in ((struct sockaddr_in *) &bindaddr, NULL, bind_port);
-        if( bind (outsockfd, &bindaddr, sizeof (bindaddr)) ) {
-            fprintf (stderr, "bind failure\n" );
+        e = getaddrinfo (NULL, bind_port, &hints, &bindaddr);
+        if (e) {
+            retval = 1;
+            fprintf (stderr, "getaddrinfo(NULL, \"%s\", ...) failed: %s\n", peer_port, gai_strerror (e));
+            goto cleanup;
+        }
+
+        for (rp = bindaddr; rp != NULL; rp = rp->ai_next) {
+            outsockfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+
+            if (outsockfd == -1) {
+                fprintf (stderr, "Can't open socket: %s", gai_strerror(errno));
+                continue;
+            }
+
+            if (bind (outsockfd, rp->ai_addr, rp->ai_addrlen) == 0) {
+                break;
+            }
+
+            close (outsockfd);
+        }
+
+        freeaddrinfo (bindaddr);
+
+        if (rp == NULL) {
+            /* No address succeeded */
+            retval = 1;
+            fprintf (stderr, "bind failure: %s\n", gai_strerror (errno));
+            goto cleanup;
         }
     }
+
     if (reply_port) {
-        init_sockaddr_in ((struct sockaddr_in *) &bindaddr, NULL, reply_port);
-        if( bind (insockfd, &bindaddr, sizeof (bindaddr)) ) {
-            fprintf (stderr, "bind failure\n" );
+        e = getaddrinfo (NULL, reply_port, &hints, &bindaddr);
+        if (e) {
+            retval = 1;
+            fprintf (stderr, "getaddrinfo(NULL, \"%s\", ...) failed: %s\n", peer_port, gai_strerror (e));
+            goto cleanup;
+        }
+
+        for (rp = bindaddr; rp != NULL; rp = rp->ai_next) {
+            insockfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+
+            if (outsockfd == -1) {
+                fprintf (stderr, "Can't open socket: %s", gai_strerror(errno));
+                continue;
+            }
+
+            if (bind (outsockfd, rp->ai_addr, rp->ai_addrlen) == 0) {
+                break;
+            }
+
+            close (insockfd);
+        }
+
+        freeaddrinfo (bindaddr);
+
+        if (rp == NULL) {
+            /* No address succeeded */
+            retval = 1;
+            fprintf (stderr, "bind failure: %s\n", gai_strerror (errno));
+            goto cleanup;
         }
     }
 
@@ -741,7 +776,15 @@ main (int argc, char *argv[])
         }
     }
 
-    jack_client_close (client);
-    packet_cache_free (packcache);
-    exit (0);
+cleanup:
+    if (destaddr) {
+        freeaddrinfo(destaddr);
+    }
+    if (client) {
+        jack_client_close (client);
+    }
+    if (packcache) {
+        packet_cache_free (packcache);
+    }
+    return retval;
 }