Add the ability to dump all traffic going through route() over a control connection.

[tinc] / src / tincctl.c

diff --git a/src/tincctl.c b/src/tincctl.c
index 641fb9c..000d383 100644 (file)
--- a/src/tincctl.c
+++ b/src/tincctl.c
@@ -98,6 +98,7 @@ static void usage(bool status) {
 #ifdef HAVE_CURSES
                                "  top                        Show real-time statistics\n"
 #endif
+                               "  pcap                       Dump traffic in pcap format\n"
                                "\n");
                printf("Report bugs to tinc@tinc-vpn.org.\n");
        }
@@ -301,9 +302,10 @@ static void make_names(void) {
        }
 }
 
+static char buffer[4096];
+static size_t blen = 0;
+
 bool recvline(int fd, char *line, size_t len) {
-       static char buffer[4096];
-       static size_t blen = 0;
        char *newline = NULL;
 
        while(!(newline = memchr(buffer, '\n', blen))) {
@@ -328,6 +330,23 @@ bool recvline(int fd, char *line, size_t len) {
        return true;
 }
 
+bool recvdata(int fd, char *data, size_t len) {
+       while(blen < len) {
+               int result = recv(fd, buffer + blen, sizeof buffer - blen, 0);
+               if(result == -1 && errno == EINTR)
+                       continue;
+               else if(result <= 0)
+                       return false;
+               blen += result;
+       }
+
+       memcpy(data, buffer, len);
+       memmove(buffer, buffer + len, blen - len);
+       blen -= len;
+
+       return true;
+}
+
 bool sendline(int fd, char *format, ...) {
        static char buffer[4096];
        char *p = buffer;
@@ -357,6 +376,57 @@ bool sendline(int fd, char *format, ...) {
        return true;    
 }
 
+void pcap(int fd, FILE *out) {
+       sendline(fd, "%d %d", CONTROL, REQ_PCAP);
+       char data[9018];
+
+       struct {
+               uint32_t magic;
+               uint16_t major;
+               uint16_t minor;
+               uint32_t tz_offset;
+               uint32_t tz_accuracy;
+               uint32_t snaplen;
+               uint32_t ll_type;
+       } header = {
+               0xa1b2c3d4,
+               2, 4,
+               0, 0,
+               sizeof data,
+               1,
+       };
+
+       struct {
+               uint32_t tv_sec;
+               uint32_t tv_usec;
+               uint32_t len;
+               uint32_t origlen;
+       } packet;
+
+       struct timeval tv;
+
+       fwrite(&header, sizeof header, 1, out);
+       fflush(out);
+
+       char line[32];
+       while(recvline(fd, line, sizeof line)) {
+               int code, req, len;
+               int n = sscanf(line, "%d %d %d", &code, &req, &len);
+               gettimeofday(&tv, NULL);
+               if(n != 3 || code != CONTROL || req != REQ_PCAP || len < 0 || len > sizeof data)
+                       break;
+               if(!recvdata(fd, data, len))
+                       break;
+               packet.tv_sec = tv.tv_sec;
+               packet.tv_usec = tv.tv_usec;
+               packet.len = len;
+               packet.origlen = len;
+               fwrite(&packet, sizeof packet, 1, out);
+               fwrite(data, len, 1, out);
+               fflush(out);
+       }
+}
+
 int main(int argc, char *argv[], char *envp[]) {
        int fd;
        int result;
@@ -636,6 +706,11 @@ int main(int argc, char *argv[], char *envp[]) {
        }
 #endif
 
+       if(!strcasecmp(argv[optind], "pcap")) {
+               pcap(fd, stdout);
+               return 0;
+       }
+
        fprintf(stderr, "Unknown command `%s'.\n", argv[optind]);
        usage(true);