xfer: fix DCC file receive on Termux (closes #1811)

This fixes such error displayed on Termux when receiving a DCC file:

xfer: invalid address "96747949": error 8 hostname nor servname provided, or not known

3 files changed, 124 insertions, 66 deletions

diff --git a/src/plugins/xfer/xfer-network.c b/src/plugins/xfer/xfer-network.c
index aa19be6a8..446c13db1 100644
--- a/src/plugins/xfer/xfer-network.c
+++ b/src/plugins/xfer/xfer-network.c
@@ -29,9 +29,11 @@
 #include <sys/wait.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <netdb.h>
+#include <resolv.h>
 #include <signal.h>
 #include <time.h>
-#include <netdb.h>
 
 #include "../weechat-plugin.h"
 #include "xfer.h"
@@ -43,6 +45,110 @@
 
 
 /*
+ * Converts integer address (as string) to IPv4 string using notation
+ * "a.b.c.d".
+ *
+ * For example: "3232235778" -> "192.168.1.2"
+ *
+ * Note: result must be freed after use.
+ */
+
+char *
+xfer_network_convert_integer_to_ipv4 (const char *str_address)
+{
+    char *error, result[64];
+    long number;
+
+    if (!str_address || !str_address[0])
+        return NULL;
+
+    number = strtol (str_address, &error, 10);
+    if (!error || error[0] || (number <= 0))
+        return NULL;
+
+    snprintf (result, sizeof (result),
+              "%ld.%ld.%ld.%ld",
+              (number >> 24) & 0xFF,
+              (number >> 16) & 0xFF,
+              (number >> 8) & 0xFF,
+              number & 0xFF);
+
+    return strdup (result);
+}
+
+/*
+ * Resolves address.
+ *
+ * Returns:
+ *   1: OK
+ *   0: error
+ */
+
+int
+xfer_network_resolve_addr (const char *str_address, const char *str_port,
+                           struct sockaddr *addr, socklen_t *addr_len,
+                           int ai_flags)
+{
+    struct addrinfo *ainfo, hints;
+    char *converted_address;
+    int rc;
+
+    memset (&hints, 0, sizeof (struct addrinfo));
+    hints.ai_flags = ai_flags;
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_socktype = SOCK_STREAM;
+    hints.ai_protocol = 0;
+    hints.ai_canonname = NULL;
+    hints.ai_addr = NULL;
+    hints.ai_next = NULL;
+
+    res_init ();
+
+    rc = getaddrinfo (str_address, str_port, &hints, &ainfo);
+
+    /*
+     * workaround for termux where an IP address as integer is not supported:
+     * it returns an error EAI_NONAME (8); in this case we manually convert
+     * the integer to IPv4 string, for example: 3232235778 -> 192.168.1.2
+     */
+    if (rc == EAI_NONAME)
+    {
+        converted_address = xfer_network_convert_integer_to_ipv4 (str_address);
+        if (converted_address)
+        {
+            rc = getaddrinfo (converted_address, str_port, &hints, &ainfo);
+            free (converted_address);
+        }
+    }
+
+    if ((rc == 0) && ainfo && ainfo->ai_addr)
+    {
+        if (ainfo->ai_addrlen > *addr_len)
+        {
+            weechat_printf (NULL,
+                            _("%s%s: address \"%s\" resolved to a larger "
+                              "sockaddr than expected"),
+                            weechat_prefix ("error"), XFER_PLUGIN_NAME,
+                            str_address);
+            freeaddrinfo (ainfo);
+            return 0;
+        }
+        memcpy (addr, ainfo->ai_addr, ainfo->ai_addrlen);
+        *addr_len = ainfo->ai_addrlen;
+        freeaddrinfo (ainfo);
+        return 1;
+    }
+
+    weechat_printf (NULL,
+                    _("%s%s: invalid address \"%s\": error %d %s"),
+                    weechat_prefix ("error"), XFER_PLUGIN_NAME,
+                    str_address, rc, gai_strerror (rc));
+    if ((rc == 0) && ainfo)
+        freeaddrinfo (ainfo);
+    return 0;
+}
+
+/*
  * Creates pipe for communication with child process.
  *
  * Returns:
diff --git a/src/plugins/xfer/xfer-network.h b/src/plugins/xfer/xfer-network.h
index cb9be323e..1790d3494 100644
--- a/src/plugins/xfer/xfer-network.h
+++ b/src/plugins/xfer/xfer-network.h
@@ -20,6 +20,13 @@
 #ifndef WEECHAT_PLUGIN_XFER_NETWORK_H
 #define WEECHAT_PLUGIN_XFER_NETWORK_H
 
+#include <sys/socket.h>
+
+extern int xfer_network_resolve_addr (const char *str_address,
+                                      const char *str_port,
+                                      struct sockaddr *addr,
+                                      socklen_t *addr_len,
+                                      int ai_flags);
 extern void xfer_network_write_pipe (struct t_xfer *xfer, int status,
                                      int error);
 extern void xfer_network_connect_init (struct t_xfer *xfer);
diff --git a/src/plugins/xfer/xfer.c b/src/plugins/xfer/xfer.c
index 331c5f521..20879836b 100644
--- a/src/plugins/xfer/xfer.c
+++ b/src/plugins/xfer/xfer.c
@@ -28,10 +28,7 @@
 #include <sys/stat.h>
 #include <time.h>
 #include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/nameser.h>
 #include <netdb.h>
-#include <resolv.h>
 #include <gcrypt.h>
 #include <arpa/inet.h>
 
@@ -971,59 +968,6 @@ xfer_free_all ()
 }
 
 /*
- * Resolves address.
- *
- * Returns:
- *   1: OK
- *   0: error
- */
-
-int
-xfer_resolve_addr (const char *str_address, const char *str_port,
-                   struct sockaddr *addr, socklen_t *addr_len, int ai_flags)
-{
-    struct addrinfo *ainfo, hints;
-    int rc;
-
-    memset (&hints, 0, sizeof (struct addrinfo));
-    hints.ai_flags = ai_flags;
-    hints.ai_family = AF_UNSPEC;
-    hints.ai_socktype = SOCK_STREAM;
-    hints.ai_protocol = 0;
-    hints.ai_canonname = NULL;
-    hints.ai_addr = NULL;
-    hints.ai_next = NULL;
-
-    res_init ();
-    rc = getaddrinfo (str_address, str_port, &hints, &ainfo);
-    if ((rc == 0) && ainfo && ainfo->ai_addr)
-    {
-        if (ainfo->ai_addrlen > *addr_len)
-        {
-            weechat_printf (NULL,
-                            _("%s%s: address \"%s\" resolved to a larger "
-                              "sockaddr than expected"),
-                            weechat_prefix ("error"), XFER_PLUGIN_NAME,
-                            str_address);
-            freeaddrinfo (ainfo);
-            return 0;
-        }
-        memcpy (addr, ainfo->ai_addr, ainfo->ai_addrlen);
-        *addr_len = ainfo->ai_addrlen;
-        freeaddrinfo (ainfo);
-        return 1;
-    }
-
-    weechat_printf (NULL,
-                    _("%s%s: invalid address \"%s\": error %d %s"),
-                    weechat_prefix ("error"), XFER_PLUGIN_NAME,
-                    str_address, rc, gai_strerror (rc));
-    if ((rc == 0) && ainfo)
-        freeaddrinfo (ainfo);
-    return 0;
-}
-
-/*
  * Callback for signal "xfer_add".
  */
 
@@ -1208,9 +1152,9 @@ xfer_add_cb (const void *pointer, void *data,
         snprintf (str_port_temp, sizeof (str_port_temp), "%d", port);
         str_port = str_port_temp;
         length = sizeof (addr);
-        if (!xfer_resolve_addr (str_address, str_port,
-                                (struct sockaddr*)&addr, &length,
-                                AI_NUMERICSERV | AI_NUMERICHOST))
+        if (!xfer_network_resolve_addr (str_address, str_port,
+                                        (struct sockaddr*)&addr, &length,
+                                        AI_NUMERICSERV | AI_NUMERICHOST))
         {
             goto error;
         }
@@ -1227,9 +1171,10 @@ xfer_add_cb (const void *pointer, void *data,
             str_address = weechat_config_string (xfer_config_network_own_ip);
             length = sizeof (own_ip_addr);
 
-            if (!xfer_resolve_addr (str_address, NULL,
-                                    (struct sockaddr*)&own_ip_addr, &length,
-                                    AI_NUMERICSERV))
+            if (!xfer_network_resolve_addr (str_address, NULL,
+                                            (struct sockaddr*)&own_ip_addr,
+                                            &length,
+                                            AI_NUMERICSERV))
             {
                 goto error;
             }
@@ -1245,9 +1190,9 @@ xfer_add_cb (const void *pointer, void *data,
             /* no own_ip, so bind_addr's family comes from irc connection  */
             str_address = weechat_infolist_string (infolist, "local_address");
             length = sizeof (addr);
-            if (!xfer_resolve_addr (str_address, NULL,
-                                    (struct sockaddr*)&addr, &length,
-                                    AI_NUMERICSERV | AI_NUMERICHOST))
+            if (!xfer_network_resolve_addr (str_address, NULL,
+                                            (struct sockaddr*)&addr, &length,
+                                            AI_NUMERICSERV | AI_NUMERICHOST))
             {
                 goto error;
             }