write_prometheus plugin: Don't construct struct sockaddr_in6 manually.

On FreeBSD, the struct is an incomplete type.

diff --git a/src/write_prometheus.c b/src/write_prometheus.c
index 21bfb54..56a3174 100644 (file)
--- a/src/write_prometheus.c
+++ b/src/write_prometheus.c
@@ -732,45 +732,54 @@ metric_family_get(data_set_t const *ds, value_list_t const *vl, size_t ds_index,
 /* }}} */
 
 #if MHD_VERSION >= 0x00090000
-static int prom_open_socket(int domain, struct sockaddr const *addr,
-                            socklen_t addrlen) {
-  int fd = socket(domain, SOCK_STREAM | SOCK_CLOEXEC, 0);
-  if (fd == -1)
-    return errno;
-
-  if (bind(fd, addr, addrlen) != 0) {
-    close(fd);
+static int prom_open_socket(int addrfamily) {
+  /* {{{ */
+  char service[NI_MAXSERV];
+  snprintf(service, sizeof(service), "%hu", httpd_port);
+
+  struct addrinfo *res;
+  int status = getaddrinfo(NULL, service,
+                           &(struct addrinfo){
+                               .ai_flags = AI_PASSIVE | AI_ADDRCONFIG,
+                               .ai_family = addrfamily,
+                               .ai_socktype = SOCK_STREAM,
+                           },
+                           &res);
+  if (status != 0) {
     return -1;
   }
 
-  if (listen(fd, /* backlog = */ 16) != 0) {
-    close(fd);
-    return -1;
-  }
+  int fd = -1;
+  for (struct addrinfo *ai = res; ai != NULL; ai = ai->ai_next) {
+    fd = socket(ai->ai_family, ai->ai_socktype | SOCK_CLOEXEC, 0);
+    if (fd == -1)
+      continue;
 
-  return fd;
-}
+    if (bind(fd, ai->ai_addr, ai->ai_addrlen) != 0) {
+      close(fd);
+      fd = -1;
+      continue;
+    }
 
-static struct MHD_Daemon *prom_start_daemon() {
-  struct sockaddr_in6 sa6 = {
-      .sin6_family = AF_INET6,
-      .sin6_port = htons(httpd_port),
-      .sin6_addr = IN6ADDR_ANY_INIT,
-  };
-  int fd = prom_open_socket(PF_INET6, (void *)&sa6, sizeof(sa6));
+    if (listen(fd, /* backlog = */ 16) != 0) {
+      close(fd);
+      fd = -1;
+      continue;
+    }
 
-  if (fd == -1) {
-    struct sockaddr_in sa4 = {
-        .sin_family = AF_INET,
-        .sin_port = htons(httpd_port),
-        .sin_addr =
-            {
-                .s_addr = INADDR_ANY,
-            },
-    };
-    fd = prom_open_socket(PF_INET, (void *)&sa4, sizeof(sa4));
+    break;
   }
 
+  freeaddrinfo(res);
+
+  return fd;
+} /* }}} int prom_open_socket */
+
+static struct MHD_Daemon *prom_start_daemon() {
+  /* {{{ */
+  int fd = prom_open_socket(PF_INET6);
+  if (fd == -1)
+    fd = prom_open_socket(PF_INET);
   if (fd == -1) {
     ERROR("write_prometheus plugin: Opening a listening socket failed.");
     return NULL;
@@ -788,9 +797,10 @@ static struct MHD_Daemon *prom_start_daemon() {
   }
 
   return d;
-}
+} /* }}} struct MHD_Daemon *prom_start_daemon */
 #else /* if MHD_VERSION < 0x00090000 */
 static struct MHD_Daemon *prom_start_daemon() {
+  /* {{{ */
   struct MHD_Daemon *d =
       MHD_start_daemon(MHD_USE_THREAD_PER_CONNECTION, 0,
                        /* MHD_AcceptPolicyCallback = */ NULL,
@@ -802,7 +812,7 @@ static struct MHD_Daemon *prom_start_daemon() {
   }
 
   return d;
-}
+} /* }}} struct MHD_Daemon *prom_start_daemon */
 #endif
 
 /*