Add c-ares support

Replace udns with c-ares

README.md

@@ -12,7 +12,7 @@ e.g. Ubuntu, Debian or Linux Mint, you can build the binary like this:
 
 ```bash
 # Debian / Ubuntu
-sudo apt-get install --no-install-recommends build-essential autoconf libtool libssl-dev libpcre3-dev libudns-dev libev-dev asciidoc xmlto automake
+sudo apt-get install --no-install-recommends build-essential autoconf libtool libssl-dev libpcre3-dev libc-ares-dev libev-dev asciidoc xmlto automake
 # CentOS / Fedora / RHEL
 sudo yum install gcc autoconf libtool automake make zlib-devel openssl-devel asciidoc xmlto
 # Arch

configure.ac

@@ -173,6 +173,8 @@ case $host in
     #include <sys/socket.h>
     #endif
     ]])
+    dnl Checks for c-ares headers
+    AC_CHECK_HEADERS([ares.h], [], [AC_MSG_ERROR([Couldn't find libcares. Try installing libc-ares-dev or c-ares-devel.])], [])
     ;;
   *)
     # These are POSIX-like systems using BSD-like sockets API.
@@ -236,7 +238,7 @@ AC_CHECK_LIB(socket, connect)
 dnl Checks for library functions.
 AC_CHECK_FUNCS([malloc memset socket])
 
-AC_CHECK_LIB([udns], [dns_dnlen], [LIBS="-ludns $LIBS"], [AC_MSG_ERROR([Couldn't find libudns. Try installing libudns-dev or udns-devel.])])
+AC_CHECK_LIB([cares], [ares_library_init], [LIBS="-lcares $LIBS"], [AC_MSG_ERROR([Couldn't find libc-ares. Try installing libc-ares-dev or c-ares-devel.])])
 
 AC_CHECK_LIB([ev], [ev_loop_destroy], [LIBS="-lev $LIBS"], [AC_MSG_ERROR([Couldn't find libev. Try installing libev-dev@<:@el@:>@.])])
 

src/Makefile.am

@@ -38,8 +38,8 @@ obfs_server_SOURCES = utils.c \
 
 obfs_local_LDADD = $(OBFS_COMMON_LIBS)
 obfs_server_LDADD = $(OBFS_COMMON_LIBS)
-obfs_local_LDADD += -ludns
-obfs_server_LDADD += -ludns
+obfs_local_LDADD += -lcares
+obfs_server_LDADD += -lcares
 
 obfs_local_CFLAGS = $(AM_CFLAGS) -DMODULE_LOCAL
 obfs_server_CFLAGS = $(AM_CFLAGS) -DMODULE_REMOTE

src/local.c

@@ -49,7 +49,6 @@
 #endif
 
 #include <libcork/core.h>
-#include <udns.h>
 
 #ifdef __MINGW32__
 #include "win32.h"

src/netutils.c

@@ -23,7 +23,6 @@
 #include <math.h>
 
 #include <libcork/core.h>
-#include <udns.h>
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
@@ -34,6 +33,7 @@
 #define sleep(n) Sleep(1000 * (n))
 #else
 #include <sys/socket.h>
+#include <arpa/inet.h>
 #include <netdb.h>
 #include <netinet/in.h>
 #include <unistd.h>
@@ -103,12 +103,12 @@ bind_to_address(int socket_fd, const char *host)
         if (cork_ip_init(&ip, host) != -1) {
             if (ip.version == 4) {
                 struct sockaddr_in *addr = (struct sockaddr_in *)&storage;
-                dns_pton(AF_INET, host, &addr->sin_addr);
+                inet_pton(AF_INET, host, &addr->sin_addr);
                 addr->sin_family = AF_INET;
                 return bind(socket_fd, (struct sockaddr *)addr, sizeof(struct sockaddr_in));
             } else if (ip.version == 6) {
                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *)&storage;
-                dns_pton(AF_INET6, host, &addr->sin6_addr);
+                inet_pton(AF_INET6, host, &addr->sin6_addr);
                 addr->sin6_family = AF_INET6;
                 return bind(socket_fd, (struct sockaddr *)addr, sizeof(struct sockaddr_in6));
             }
@@ -127,14 +127,14 @@ get_sockaddr(char *host, char *port,
         if (ip.version == 4) {
             struct sockaddr_in *addr = (struct sockaddr_in *)storage;
             addr->sin_family = AF_INET;
-            dns_pton(AF_INET, host, &(addr->sin_addr));
+            inet_pton(AF_INET, host, &(addr->sin_addr));
             if (port != NULL) {
                 addr->sin_port = htons(atoi(port));
             }
         } else if (ip.version == 6) {
             struct sockaddr_in6 *addr = (struct sockaddr_in6 *)storage;
             addr->sin6_family = AF_INET6;
-            dns_pton(AF_INET6, host, &(addr->sin6_addr));
+            inet_pton(AF_INET6, host, &(addr->sin6_addr));
             if (port != NULL) {
                 addr->sin6_port = htons(atoi(port));
             }