From 1305e5ddd4634f5ebd6dc3577de59320650ea7cd Mon Sep 17 00:00:00 2001
From: picronsin <gaogedaxinwenz@gmail.com>
Date: Mon, 21 Nov 2022 17:45:20 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20=E6=96=B0=E5=A2=9E=E7=BD=91=E5=8D=A1?=
 =?UTF-8?q?=E9=80=89=E6=8B=A9?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md     |  2 ++
 auth.c        | 17 +++++++++++++++++
 configparse.c |  1 +
 configparse.h |  1 +
 main.c        | 10 +++++++++-
 5 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 0984eba..1aff73e 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ Options:
         --conf <FILEPATH>, -c <FILEPATH>      import configuration file
         --bindip <IPADDR>, -b <IPADDR>        bind your ip address(default is 0.0.0.0)
         --log <LOGPATH>, -l <LOGPATH>         specify log file
+        --interface <IFNAME>, -i <IFNAME>     bind interface
         --802.1x, -x                          enable 802.1x
         --daemon, -d                          set daemon flag
         --eternal, -e                         set eternal flag
@@ -30,6 +31,7 @@ $ dogcom -m pppoe -c dogcom.conf -x # (PS: only on Linux build)
 $ dogcom -m pppoe -c dogcom.conf -e # eternal dogcoming (default times is 5)
 $ dogcom -m pppoe -c dogcom.conf -v
 $ dogcom -m dhcp -c dogcom.conf -b 10.2.3.12 -v
+$ dogcom -m dhcp -c dogcom.conf -i eth0.2 # (PS: only on Linux build)
 ```
 
 #### To build:
diff --git a/auth.c b/auth.c
index 57d1883..61f808a 100644
--- a/auth.c
+++ b/auth.c
@@ -12,6 +12,7 @@ typedef int socklen_t;
 #include <arpa/inet.h>
 #include <netinet/in.h>
 #include <sys/socket.h>
+#include <net/if.h>
 #endif
 
 #include "auth.h"
@@ -568,6 +569,7 @@ int dogcom(int try_times) {
 #endif
         return 1;
     }
+    
     // bind socket
     if (bind(sockfd, (struct sockaddr *)&bind_addr, sizeof(bind_addr)) < 0) {
 #ifdef WIN32
@@ -595,6 +597,21 @@ int dogcom(int try_times) {
         return 1;
     }
 
+    // bind interface
+#ifdef linux
+    if (strlen(bind_ifr_name) > 0)
+    {
+        struct ifreq ifr;
+        memset(&ifr, 0, sizeof(ifr));
+        strcpy(ifr.ifr_name, bind_ifr_name);
+        if (setsockopt(sockfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
+        {
+            perror("Failed to bind ifr");
+            return 1;
+        }
+    }
+#endif
+
     // start dogcoming
     if (strcmp(mode, "dhcp") == 0) {
         int login_failed_attempts = 0;
diff --git a/configparse.c b/configparse.c
index 5b4d4d0..e1db35c 100644
--- a/configparse.c
+++ b/configparse.c
@@ -11,6 +11,7 @@ int eternal_flag = 0;
 char *log_path;
 char mode[10];
 char bind_ip[20];
+char bind_ifr_name[20];
 struct config drcom_config;
 
 static int read_d_config(char *buf, int size);
diff --git a/configparse.h b/configparse.h
index 1bd5648..f8e4392 100644
--- a/configparse.h
+++ b/configparse.h
@@ -30,6 +30,7 @@ extern int eternal_flag;
 extern char *log_path;
 extern char mode[10];
 extern char bind_ip[20];
+extern char bind_ifr_name[20];
 
 int config_parse(char *filepath);
 
diff --git a/main.c b/main.c
index 19b2440..391fbcd 100644
--- a/main.c
+++ b/main.c
@@ -33,6 +33,7 @@ int main(int argc, char *argv[]) {
             {"bindip", required_argument, 0, 'b'},
             {"log", required_argument, 0, 'l'},
 #ifdef linux
+            {"interface", required_argument,0, 'i'}, 
             {"daemon", no_argument, 0, 'd'},
             {"802.1x", no_argument, 0, 'x'},
 #endif
@@ -44,7 +45,7 @@ int main(int argc, char *argv[]) {
         int c;
         int option_index = 0;
 #ifdef linux
-        c = getopt_long(argc, argv, "m:c:b:l:dxevh", long_options, &option_index);
+        c = getopt_long(argc, argv, "m:c:b:l:i:dxevh", long_options, &option_index);
 #else
         c = getopt_long(argc, argv, "m:c:b:l:evh", long_options, &option_index);
 #endif
@@ -98,6 +99,9 @@ int main(int argc, char *argv[]) {
 #endif
                 break;
 #ifdef linux
+            case 'i':
+                strcpy(bind_ifr_name, optarg);
+                break;
             case 'd':
                 daemon_flag = 1;
                 break;
@@ -151,6 +155,9 @@ int main(int argc, char *argv[]) {
             if (strlen(bind_ip) == 0) {
                 memcpy(bind_ip, default_bind_ip, sizeof(default_bind_ip));
             }
+            if (strlen(bind_ifr_name) == 0) {
+                memset(bind_ifr_name, 0, 20);
+            }
             dogcom(5);
         } else {
             return 1;
@@ -177,6 +184,7 @@ void print_help(int exval) {
     printf("\t--bindip <IPADDR>, -b <IPADDR>        bind your ip address(default is 0.0.0.0)\n");
     printf("\t--log <LOGPATH>, -l <LOGPATH>         specify log file\n");
 #ifdef linux
+    printf("\t--interface, -i                       bind interface\n");
     printf("\t--daemon, -d                          set daemon flag\n");
     printf("\t--802.1x, -x                          enable 802.1x\n");
 #endif