pmlag

commit a40b06a0e24b54bdec276dc2bbcefc0605d1cb80
parent 88008ab347a73d7352757566931d6971ff2fdc38
Author: Yersa Nordman <yersa@finwo.nl>
Date:   Sun, 12 Mar 2023 23:37:03 +0100

Set iface to promiscuous mode for sockraw

Diffstat:
M
src/util/socket.c
 | 
133
+++++++++++++++++++++++++++++++++++++++++++++----------------------------------

1 file changed, 76 insertions(+), 57 deletions(-)
diff --git a/src/util/socket.c b/src/util/socket.c
@@ -42,9 +42,21 @@ int iface_idx(int sockfd, char * ifname) {
   return ifr.ifr_ifindex;
 }
 
+int if_ioctl(int cmd, struct ifreq* req) {
+  int ret, sock;
+  sock = socket(AF_INET, SOCK_PACKET, 0);
+  if (sock < 0) {
+    return -1;
+  }
+  ret = ioctl(sock, cmd, req);
+  close(sock);
+  return ret;
+}
+
 int sockraw_open(char * ifname) {
+  struct ifreq ifr;
 
-  // Open socket
+  // Open socket (P_ALL, due to custom ethertype field)
   int sockfd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
   if (sockfd < 0) {
     perror("Error opening socket");
@@ -52,7 +64,12 @@ int sockraw_open(char * ifname) {
     return -1;
   }
 
-  // Bind socket to interface
+  /* // Bind socket to interface */
+  /* if (setsockopt(sockfd, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)) < 0) { */
+  /*   perror("Error binding raw socket to interface"); */
+  /* } */
+
+  // Old bind to socket
   struct sockaddr_ll sll;
   bzero(&sll, sizeof(sll));
   sll.sll_family   = AF_PACKET;
@@ -68,72 +85,74 @@ int sockraw_open(char * ifname) {
     return -1;
   }
 
+  // Get current iface configuration
+  memset(&ifr, 0, sizeof(ifr));
+  strcpy(ifr.ifr_name, ifname);
+  if (if_ioctl(SIOCGIFFLAGS, &ifr) < 0) {
+    perror("Get interface flags");
+  }
+
+  // Set iface to promiscuous mode
+  ifr.ifr_flags |= IFF_PROMISC;
+  if (if_ioctl(SIOCSIFFLAGS, &ifr) < 0) {
+    perror("Configure interface promiscuous mode");
+  }
+
   // Return the prepared socket
   return sockfd;
 }
 
-static int if_ioctl(int cmd, struct ifreq* req) {
-    int ret, sock;
-    sock = socket(AF_INET, SOCK_PACKET, 0);
-    if (sock < 0) {
-        return -1;
-    }
-    ret = ioctl(sock, cmd, req);
-    close(sock);
-    return ret;
-}
-
 int tap_alloc(char * ifname, unsigned char * mac) {
-    struct ifreq ifr;
-    int fd, err;
+  struct ifreq ifr;
+  int fd, err;
 
-    if( (fd = open("/dev/net/tun", O_RDWR)) < 0 ) {
-      perror("Open tun");
-      return -1;
-    }
+  if( (fd = open("/dev/net/tun", O_RDWR)) < 0 ) {
+    perror("Open tun");
+    return -1;
+  }
 
-    // Bring up the interface
-    memset(&ifr, 0, sizeof(ifr));
-    ifr.ifr_flags = IFF_TAP | IFF_MULTI_QUEUE | IFF_NO_PI;
-    if( *ifname ) {
-      strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
-    }
-    /* if ( mac ) { */
-    /*   // TODO: random, copied or specific mac address pulled from ini */
-    /*   printf("MAC: %.2X-%.2X-%.2X-%.2X-%.2X-%.2X\n",mac[0],mac[1],mac[2],mac[3],mac[4],mac[5]); */
-    /*   memset(&ifr, 0, sizeof(ifr)); */
-    /*   strcpy(ifr.ifr_name, ifname); */
-    /*   ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER; */
-    /*   memcpy(ifr.ifr_hwaddr.sa_data, mac, ETH_ALEN); */
-    /*   if ((err = if_ioctl(SIOCSIFHWADDR, &ifr)) < 0) { */
-    /*     perror("Set if hwaddr"); */
-    /*     close(fd); */
-    /*     return err; */
-    /*   } */
-    /* } */
-    if( (err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ){
-      perror("Open tun");
-      close(fd);
-      return err;
-    }
-    strcpy(ifname, ifr.ifr_name);
+  // Bring up the interface
+  memset(&ifr, 0, sizeof(ifr));
+  ifr.ifr_flags = IFF_TAP | IFF_MULTI_QUEUE | IFF_NO_PI;
+  if( *ifname ) {
+    strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
+  }
+  /* if ( mac ) { */
+  /*   // TODO: random, copied or specific mac address pulled from ini */
+  /*   printf("MAC: %.2X-%.2X-%.2X-%.2X-%.2X-%.2X\n",mac[0],mac[1],mac[2],mac[3],mac[4],mac[5]); */
+  /*   memset(&ifr, 0, sizeof(ifr)); */
+  /*   strcpy(ifr.ifr_name, ifname); */
+  /*   ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER; */
+  /*   memcpy(ifr.ifr_hwaddr.sa_data, mac, ETH_ALEN); */
+  /*   if ((err = if_ioctl(SIOCSIFHWADDR, &ifr)) < 0) { */
+  /*     perror("Set if hwaddr"); */
+  /*     close(fd); */
+  /*     return err; */
+  /*   } */
+  /* } */
+  if( (err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ){
+    perror("Open tun");
+    close(fd);
+    return err;
+  }
+  strcpy(ifname, ifr.ifr_name);
 
-    // Set interface to multicast|broadcast
-    memset(&ifr, 0, sizeof(ifr));
-    strcpy(ifr.ifr_name, ifname);
-    if (if_ioctl(SIOCGIFFLAGS, &ifr) < 0) {
+  // Set interface to multicast|broadcast
+  memset(&ifr, 0, sizeof(ifr));
+  strcpy(ifr.ifr_name, ifname);
+  if (if_ioctl(SIOCGIFFLAGS, &ifr) < 0) {
+    perror("failed to get the interface flags");
+    close(fd);
+    return err;
+  }
+  if (!(ifr.ifr_flags & IFF_UP)) {
+    ifr.ifr_flags |= IFF_UP;
+    if (if_ioctl(SIOCSIFFLAGS, &ifr) < 0) {
       perror("failed to get the interface flags");
       close(fd);
       return err;
     }
-    if (!(ifr.ifr_flags & IFF_UP)) {
-      ifr.ifr_flags |= IFF_UP;
-      if (if_ioctl(SIOCSIFFLAGS, &ifr) < 0) {
-        perror("failed to get the interface flags");
-        close(fd);
-        return err;
-      }
-    }
+  }
 
-    return fd;
+  return fd;
 }