Merge pull request #67 from krruzic/setinterface

add optional interface specification
spacemeowx2 · Jan 7, 2020 · c4f2d75 · c4f2d75
2 parents 7f61f00 + 417d310
commit c4f2d75
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Showing 5 changed files with 72 additions and 13 deletions.
diff --git a/src/lan-play.c b/src/lan-play.c
@@ -7,9 +7,9 @@ struct lan_play real_lan_play;
 uint8_t SEND_BUFFER[BUFFER_SIZE];
 void lan_play_pcap_handler(uv_pcap_t *handle, const struct pcap_pkthdr *pkt_header, const u_char *packet, const uint8_t *mac);
 
-int init_pcap(struct lan_play *lan_play)
+int init_pcap(struct lan_play *lan_play, char *netif)
 {
-    int ret = uv_pcap_init(lan_play->loop, &lan_play->pcap, lan_play_pcap_handler);
+    int ret = uv_pcap_init(lan_play->loop, &lan_play->pcap, lan_play_pcap_handler, netif);
     if (ret != 0) {
         RETURN_ERR(lan_play, "failed at uv_pcap_init");
     };
@@ -75,7 +75,7 @@ int lan_play_init(struct lan_play *lan_play)
         SHA1Final(lan_play->key, &hashctx);
     }
 
-    ret = init_pcap(lan_play);
+    ret = init_pcap(lan_play, options.netif);
     if (ret != 0) return ret;
 
     CPY_IPV4(ip, str2ip(SERVER_IP));

diff --git a/src/lan-play.h b/src/lan-play.h
@@ -93,6 +93,7 @@ struct cli_options {
     bool list_if;
 
     char *netif_ipaddr;
+    char *netif;
     char *netif_netmask;
 
     char *relay_server_addr;

diff --git a/src/main.c b/src/main.c
@@ -64,6 +64,7 @@ int parse_arguments(int argc, char **argv)
     options.fake_internet = false;
     options.list_if = false;
 
+    options.netif = NULL;
     options.netif_ipaddr = NULL;
     options.netif_netmask = NULL;
 
@@ -88,10 +89,10 @@ int parse_arguments(int argc, char **argv)
             options.help = 1;
         } else if (!strcmp(arg, "--version")) {
             options.version = 1;
-        // } else if (!strcmp(arg, "--netif-ipaddr")) {
-        //     CHECK_PARAM();
-        //     options.netif_ipaddr = argv[i + 1];
-        //     i++;
+        } else if (!strcmp(arg, "--netif")) {
+            CHECK_PARAM();
+            options.netif = strdup(argv[i + 1]);
+            i++;
         // } else if (!strcmp(arg, "--netif-netmask")) {
         //     CHECK_PARAM();
         //     options.netif_netmask = argv[i + 1];
@@ -205,7 +206,7 @@ void print_help(const char *name)
         "        [--version]\n"
         "        [--broadcast]\n"
         "        [--fake-internet]\n"
-        // "        [--netif-ipaddr <ipaddr>] default: 10.13.37.1\n"
+        "        [--netif <interface>] default: all\n"
         // "        [--netif-netmask <ipnetmask>] default: 255.255.0.0\n"
         "        [--relay-server-addr <addr>]\n"
         "        [--username <username>]\n"
@@ -307,7 +308,11 @@ int old_main()
     RT_ASSERT(uv_signal_start(&signal_int, lan_play_signal_cb, SIGINT) == 0);
     signal_int.data = lan_play;
 
-    printf("Opening interfaces\n");
+    if (options.netif == NULL) {
+        printf("Interface not specified, opening all interfaces\n");
+    } else {
+        printf("Opening single interface\n");
+    }
     RT_ASSERT(lan_play_init(lan_play) == 0);
 
     ret = uv_run(lan_play->loop, UV_RUN_DEFAULT);

diff --git a/src/pcaploop.cpp b/src/pcaploop.cpp
@@ -112,12 +112,11 @@ int uv_pcap_sendpacket(uv_pcap_t *handle, const u_char *data, int size)
     return 0;
 }
 
-int uv_pcap_init(uv_loop_t *loop, uv_pcap_t *handle, uv_pcap_cb cb)
+int uv_pcap_init(uv_loop_t *loop, uv_pcap_t *handle, uv_pcap_cb cb, char *netif)
 {
     handle->cb = cb;
     handle->inner = new uv_pcap_inner;
     auto inner = handle->inner;
-
     pcap_if_t *alldevs;
     char err_buf[PCAP_ERRBUF_SIZE];
     if (pcap_findalldevs(&alldevs, err_buf)) {
@@ -126,19 +125,73 @@ int uv_pcap_init(uv_loop_t *loop, uv_pcap_t *handle, uv_pcap_cb cb)
     }
     int i = 0;
     pcap_if_t *d;
+
     for (d = alldevs; d; d = d->next) {
         i++;
+        if (netif != NULL) {
+            int netif_index = atoi(netif);
+            if (i == netif_index) {
+                netif = strdup(d->name);
+            }
+        }
     }
     if (i == 0) {
         fprintf(stderr, "Error pcap_findalldevs 0 item\n");
         exit(1);
     }
-
     inner->interfaces = new uv_pcap_interf_t[i];
     i = 0;
     for (d = alldevs; d; d = d->next) {
         pcap_t *dev;
         int ret;
+        if (netif != NULL) {
+            if (!strcmp(d->name, netif)) {
+                printf("found interface: %s\n", d->name);
+                // found requested interface
+                dev = pcap_open_live(d->name, 65535, 1, 500, err_buf);
+                if (!dev) {
+                    LLOG(LLOG_DEBUG, "open %s fail", d->name);
+                    goto fail_single;
+                }
+
+                auto datalink = pcap_datalink(dev);
+                if (datalink != DLT_EN10MB) {
+                    LLOG(LLOG_DEBUG, "open specified interface: %s fail: datalink(%d)", d->name, datalink);
+                    goto fail_single;
+                }
+
+                uint8_t mac[6];
+                if (get_mac_address(d, dev, mac) != 0) {
+                    LLOG(LLOG_DEBUG, "open specified interface: %s fail: get mac", d->name);
+                    goto fail_single;
+                }
+                if (memcmp(EmptyMac, mac, 6) == 0) {
+                    LLOG(LLOG_DEBUG, "open specified interface: %s fail: get all zero mac", d->name);
+                    goto fail_single;
+                }
+
+                set_filter(dev, mac);
+
+                if (set_immediate_mode(dev) == -1) {
+                    LLOG(LLOG_DEBUG, "open specified interface: %s fail: set_immediate_mode %s", d->name, strerror(errno));
+                    goto fail_single;
+                }
+
+                ret = uv_pcap_interf_init(loop, &inner->interfaces[i], uv_pcap_callback, dev, mac);
+                if (ret) {
+                    LLOG(LLOG_DEBUG, "open specified interface: %s fail: pcap init", d->name);
+                    goto fail_single;
+                }
+                inner->interfaces[i].data = handle;
+                i++;
+                LLOG(LLOG_DEBUG, "open specified interface: %s ok", d->name);
+                break;
+            }
+            continue;
+            fail_single:
+                pcap_close(dev);
+                break;
+        }
 
         dev = pcap_open_live(d->name, 65535, 1, 500, err_buf);
         if (!dev) {

diff --git a/src/pcaploop.h b/src/pcaploop.h
@@ -19,7 +19,7 @@ struct uv_pcap_s {
     void *data;
 };
 
-int uv_pcap_init(uv_loop_t *loop, uv_pcap_t *handle, uv_pcap_cb cb);
+int uv_pcap_init(uv_loop_t *loop, uv_pcap_t *handle, uv_pcap_cb cb, char *netif);
 void uv_pcap_close(uv_pcap_t *handle);
 int uv_pcap_sendpacket(uv_pcap_t *handle, const u_char *data, int size);