use getaddrinfo() for client/server address resolving

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>

5 files changed, 116 insertions, 52 deletions

diff --git a/client.c b/client.c
index c8bb974..674afb9 100644
--- a/client.c
+++ b/client.c
@@ -228,13 +228,15 @@ __attribute__((noreturn)) static void cleanup_and_exit(struct event_base ** cons
 
 int main(int argc, char ** argv)
 {
+    struct addrinfo * connect_addresses = NULL;
+    struct addrinfo * ai;
+    int gai_errno;
+    int bev_connected = 0;
     struct event_base * ev_base = NULL;
     struct event * ev_sig = NULL;
     struct bufferevent * bev;
-    struct sockaddr_in sin;
     struct longterm_keypair * my_keypair = NULL;
     struct connection * c = NULL;
-
     char ip_str[INET6_ADDRSTRLEN + 1];
 
     parse_cmdline(&opts, argc, argv);
@@ -252,8 +254,14 @@ int main(int argc, char ** argv)
             return 1;
         }
     }
-    if (opts.port <= 0 || opts.port > 65535) {
-        LOG(ERROR, "Invalid port: %d", opts.port);
+    if (opts.host == NULL || opts.port == NULL) {
+        LOG(ERROR, "Invalid host/port");
+        return 2;
+    }
+    LOG(NOTICE, "Resolving %s:%s..", opts.host, opts.port);
+    gai_errno = hostname_to_address(opts.host, opts.port, &connect_addresses);
+    if (gai_errno != 0) {
+        LOG(ERROR, "Address/Service translation error for %s:%s: %s", opts.host, opts.port, gai_strerror(gai_errno));
         return 2;
     }
 
@@ -264,11 +272,6 @@ int main(int argc, char ** argv)
         return 3;
     }
 
-    if (init_sockaddr_inet(&sin, opts.host, opts.port, ip_str) != 0) {
-        return 4;
-    }
-    LOG(NOTICE, "Connecting to %s:%u", ip_str, opts.port);
-
     /* generate client keypair */
     my_keypair = generate_keypair_sodium();
     if (my_keypair == NULL) {
@@ -322,7 +325,38 @@ int main(int argc, char ** argv)
     }
     ev_set_io_timeouts(bev);
 
-    if (bufferevent_socket_connect(bev, (struct sockaddr *)&sin, sizeof(sin)) != 0) {
+    for (ai = connect_addresses; ai != NULL; ai = ai->ai_next) {
+        struct sockaddr * sa = NULL;
+        socklen_t sl = 0;
+
+        switch (ai->ai_family) {
+            case AF_INET:
+                sa = (struct sockaddr *)&((struct sockaddr_in *)ai->ai_addr)->sin_addr;
+                sl = sizeof(struct sockaddr_in);
+                break;
+            case AF_INET6:
+                sa = (struct sockaddr *)&((struct sockaddr_in6 *)ai->ai_addr)->sin6_addr;
+                sl = sizeof(struct sockaddr_in6);
+                break;
+            default:
+                LOG(ERROR, "Unknown address family: %d", ai->ai_family);
+                cleanup_and_exit(&ev_base, &ev_sig, &my_keypair, &c, 14);
+        }
+        if (inet_ntop(ai->ai_family, sa, ip_str, sl) == NULL) {
+            LOG(WARNING, "Invalid IPv4 host");
+            continue;
+        }
+
+        LOG(NOTICE, "Connecting to %s:%s", ip_str, opts.port);
+        if (bufferevent_socket_connect(bev, ai->ai_addr, ai->ai_addrlen) == 0) {
+            bev_connected = 1;
+            break;
+        }
+    }
+    freeaddrinfo(connect_addresses);
+    connect_addresses = NULL;
+
+    if (bev_connected == 0) {
         cleanup_and_exit(&ev_base, &ev_sig, &my_keypair, &c, 14);
     }
 
diff --git a/common-sodium.c b/common-sodium.c
index 1f3c88e..202eca6 100644
--- a/common-sodium.c
+++ b/common-sodium.c
@@ -94,23 +94,6 @@ int generate_session_keypair_sodium(struct connection * const state)
     return 0;
 }
 
-int init_sockaddr_inet(struct sockaddr_in * const sin,
-                       const char * const host,
-                       int port,
-                       char ip_str[INET6_ADDRSTRLEN + 1])
-{
-    memset(sin, 0, sizeof(*sin));
-    sin->sin_family = AF_INET;
-    sin->sin_port = htons(port);
-    if (inet_pton(sin->sin_family, host, &sin->sin_addr) <= 0 ||
-        inet_ntop(sin->sin_family, &sin->sin_addr, ip_str, INET6_ADDRSTRLEN) == NULL) {
-        LOG(ERROR, "Invalid host: %s", host);
-        return 1;
-    }
-
-    return 0;
-}
-
 int init_crypto_server(struct connection * const state,
                        unsigned char const * const server_rx_header,
                        size_t server_rx_header_size)
diff --git a/common-sodium.h b/common-sodium.h
index 8f218a0..b4a7d23 100644
--- a/common-sodium.h
+++ b/common-sodium.h
@@ -18,11 +18,6 @@ __attribute__((warn_unused_result)) struct longterm_keypair * generate_keypair_f
 
 __attribute__((warn_unused_result)) int generate_session_keypair_sodium(struct connection * const state);
 
-__attribute__((warn_unused_result)) int init_sockaddr_inet(struct sockaddr_in * const sin,
-                                                           const char * const host,
-                                                           int port,
-                                                           char ip_str[INET6_ADDRSTRLEN + 1]);
-
 __attribute__((warn_unused_result)) int init_crypto_server(struct connection * const state,
                                                            unsigned char const * const server_rx_header,
                                                            size_t server_rx_header_size);
diff --git a/server.c b/server.c
index 7247371..5db4392 100644
--- a/server.c
+++ b/server.c
@@ -285,12 +285,13 @@ __attribute__((noreturn)) static void cleanup_and_exit(struct event_base ** cons
 
 int main(int argc, char ** argv)
 {
+    struct addrinfo * connect_addresses = NULL;
+    struct addrinfo * ai;
+    int gai_errno;
     struct longterm_keypair * my_keypair = NULL;
     struct event_base * ev_base = NULL;
     struct event * ev_sig = NULL;
     struct evconnlistener * ev_listener = NULL;
-    struct sockaddr_in sin;
-
     char ip_str[INET6_ADDRSTRLEN + 1];
 
     parse_cmdline(&opts, argc, argv);
@@ -305,8 +306,14 @@ int main(int argc, char ** argv)
             return 1;
         }
     }
-    if (opts.port <= 0 || opts.port > 65535) {
-        LOG(ERROR, "Invalid port: %d", opts.port);
+    if (opts.host == NULL || opts.port == NULL) {
+        LOG(ERROR, "Invalid host/port");
+        return 2;
+    }
+    LOG(NOTICE, "Resolving %s:%s..", opts.host, opts.port);
+    gai_errno = hostname_to_address(opts.host, opts.port, &connect_addresses);
+    if (gai_errno != 0) {
+        LOG(ERROR, "Address/Service translation error for %s:%s: %s", opts.host, opts.port, gai_strerror(gai_errno));
         return 2;
     }
 
@@ -317,11 +324,6 @@ int main(int argc, char ** argv)
         return 2;
     }
 
-    if (init_sockaddr_inet(&sin, opts.host, opts.port, ip_str) != 0) {
-        return 3;
-    }
-    LOG(NOTICE, "Listen on %s:%u", ip_str, opts.port);
-
     if (opts.key_string != NULL) {
         my_keypair = generate_keypair_from_secretkey_hexstr_sodium(opts.key_string, opts.key_length);
     } else {
@@ -351,17 +353,46 @@ int main(int argc, char ** argv)
         cleanup_and_exit(&ev_base, &ev_listener, &ev_sig, &my_keypair, 7);
     }
 
-    ev_listener = evconnlistener_new_bind(ev_base,
-                                          accept_conn_cb,
-                                          my_keypair,
-                                          LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE,
-                                          -1,
-                                          (struct sockaddr *)&sin,
-                                          sizeof(sin));
+    for (ai = connect_addresses; ai != NULL; ai = ai->ai_next) {
+        struct sockaddr * sa = NULL;
+        socklen_t sl = 0;
+
+        switch (ai->ai_family) {
+            case AF_INET:
+                sa = (struct sockaddr *)&((struct sockaddr_in *)ai->ai_addr)->sin_addr;
+                sl = sizeof(struct sockaddr_in);
+                break;
+            case AF_INET6:
+                sa = (struct sockaddr *)&((struct sockaddr_in6 *)ai->ai_addr)->sin6_addr;
+                sl = sizeof(struct sockaddr_in6);
+                break;
+            default:
+                LOG(ERROR, "Unknown address family: %d", ai->ai_family);
+                cleanup_and_exit(&ev_base, &ev_listener, &ev_sig, &my_keypair, 8);
+        }
+        if (inet_ntop(ai->ai_family, sa, ip_str, sl) == NULL) {
+            LOG(WARNING, "Invalid IPv4 host");
+            continue;
+        }
+
+        LOG(NOTICE, "Listening on %s:%s", ip_str, opts.port);
+        ev_listener = evconnlistener_new_bind(ev_base,
+                                              accept_conn_cb,
+                                              my_keypair,
+                                              LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE,
+                                              -1, ai->ai_addr, ai->ai_addrlen);
+        if (ev_listener != NULL) {
+            break;
+        }
+    }
+    freeaddrinfo(connect_addresses);
+    connect_addresses = NULL;
+
     if (ev_listener == NULL) {
         LOG(ERROR, "Couldn't create listener: %s", strerror(errno));
         cleanup_and_exit(&ev_base, &ev_listener, &ev_sig, &my_keypair, 8);
     }
+
     evconnlistener_set_error_cb(ev_listener, accept_error_cb);
     event_base_dispatch(ev_base);
 
diff --git a/utils.h b/utils.h
index b9fff6e..0774007 100644
--- a/utils.h
+++ b/utils.h
@@ -1,9 +1,12 @@
 #ifndef UTILS_H
 #define UTILS_H 1
 
+#include <netdb.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
 #include <unistd.h>
 
 struct cmd_options {
@@ -19,7 +22,7 @@ struct cmd_options {
     /* server: listen port
      * client: remote port
      */
-    int port;
+    char * port;
     /* server: path to write to, received from client via PDU-type DATA
      * client: path to read from, send it via PDU-type DATA
      */
@@ -46,7 +49,7 @@ static inline void parse_cmdline(struct cmd_options * const opts, int argc, char
                 opts->host = strdup(optarg);
                 break;
             case 'p':
-                opts->port = atoi(optarg); /* meh, strtol is king */
+                opts->port = strdup(optarg);
                 break;
             case 'f':
                 opts->filepath = strdup(optarg);
@@ -59,8 +62,8 @@ static inline void parse_cmdline(struct cmd_options * const opts, int argc, char
     if (opts->host == NULL) {
         opts->host = strdup("127.0.0.1");
     }
-    if (opts->port == 0) {
-        opts->port = 5555;
+    if (opts->port == NULL) {
+        opts->port = strdup("5555");
     }
     if (opts->key_string != NULL) {
         opts->key_length = strlen(opts->key_string);
@@ -86,4 +89,22 @@ static inline char * prettify_bytes_with_units(char * const out, size_t out_size
     return out;
 }
 
+static inline int hostname_to_address(char const * const host, char const * const port,
+                                      struct addrinfo ** const result)
+{
+    int s;
+    struct addrinfo hints;
+
+    memset(&hints, 0, sizeof(struct addrinfo));
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_socktype = SOCK_STREAM;
+    hints.ai_flags = AI_PASSIVE;
+
+    s = getaddrinfo(host, port, &hints, result);
+    if (s != 0) {
+        return s;
+    }
+
+    return 0;
+}
 #endif