pmlag

commit 5851fbeb8f3648f336c77c47eb8c371b696bd567
parent ed433bd013ee2de115c697293baee8f117f040ba
Author: Robin Bron <robin@finwo.nl>
Date:   Sun, 12 Feb 2023 22:27:06 +0100

Tap iface created

Diffstat:
M
src/main.c
 | 
27
+++++++++++++++++----------
M
src/socket.c
 | 
35
++++++++++++++++++++++++++++++++++-
M
src/socket.h
 | 
1
+
M
test.ini
 | 
4
+---

4 files changed, 53 insertions(+), 14 deletions(-)
diff --git a/src/main.c b/src/main.c
@@ -55,10 +55,6 @@ void * thread_iface(void *arg) {
   }
 
   // Find bond socket iface_idx
-  struct sockaddr_ll sadr_ll;
-  sadr_ll.sll_halen = ETH_ALEN; // length of destination mac address */
-  int bond_fd       = iface->bond->sockfd;
-  int bond_idx      = iface_idx(bond_fd, iface->bond->name);
   int send_len;
 
   while(1) {
@@ -74,12 +70,19 @@ void * thread_iface(void *arg) {
 
     // TODO: track received proto=0x0666 packet to update routing table
 
+    /* printf("\n"); */
+    /* printf("Got packet: %d bytes\n", buflen); */
+    /* printf("\n"); */
+
+    /* printf("Ethernet header\n"); */
+    /* printf("\t|- DST    %.2X-%.2X-%.2X-%.2X-%.2X-%.2X\n",buffer[0],buffer[1],buffer[2],buffer[3],buffer[ 4],buffer[ 5]); */
+    /* printf("\t|- SRC    %.2X-%.2X-%.2X-%.2X-%.2X-%.2X\n",buffer[6],buffer[7],buffer[8],buffer[9],buffer[10],buffer[11]); */
+    /* printf("\t|- PROTO  %.4X\n", ((int)((char)buffer[12]) << 8) + buffer[13]); */
+
     // Redirect packet to bond socket as-is
-    sadr_ll.sll_ifindex = bond_idx;
-    memcpy(sadr_ll.sll_addr, buffer, ETH_ALEN);
-    send_len = sendto(bond_fd, buffer, buflen, 0, (const struct sockaddr*)&sadr_ll, sizeof(struct sockaddr_ll));
+    send_len = write(iface->bond->sockfd, buffer, buflen);
     if (buflen != send_len) {
-      perror("sendto");
+      perror("write(bond)");
       pthread_exit(NULL);
       return NULL;
     }
@@ -94,7 +97,9 @@ void * thread_bond(void *arg) {
   struct pmlag_bond *bond = (struct pmlag_bond *)arg;
   printf("Thread started for bond: %s\n", bond->name);
 
-  // For each bond of config->bonds
+
+
+  // Start thread for each interface of this bond
   struct pmlag_iface *iface = bond->interfaces;
   while(iface) {
     if(pthread_create(&(iface->tid), NULL, thread_iface, iface)) {
@@ -105,7 +110,9 @@ void * thread_bond(void *arg) {
     iface = iface->next;
   }
 
-  // TODO: open tun/tap device
+  // Take mac address of last iface
+  bond->sockfd = tap_alloc(bond->name);
+
   // TODO: blocked listen on bond, send through routing table to other ifaces
   // TODO: send broadcasts to all interfaces
   // TODO: timer to broadcast announce our presence to ifaces (vrrp-ish)
diff --git a/src/socket.c b/src/socket.c
@@ -1,11 +1,13 @@
-#include <linux/if_ether.h>
+#include <fcntl.h>
 #include <linux/if_packet.h>
+#include <linux/if_tun.h>
 #include <net/if.h>
 #include <netinet/in.h>
 #include <string.h>
 #include <strings.h>
 #include <sys/ioctl.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <sys/socket.h>
 #include <unistd.h>
 
@@ -18,6 +20,7 @@ int iface_idx(int sockfd, char * ifname) {
   // Get interface index
   strncpy((char *)ifr.ifr_name, ifname, IFNAMSIZ);
   if ((ioctl(sockfd, SIOCGIFINDEX, &ifr)) == -1) {
+    fprintf(stderr, "Error getting interface index for %s\n", ifname);
     perror("Error getting interface index");
     close(sockfd);
     return -1;
@@ -55,3 +58,33 @@ int sockraw_open(char * ifname) {
   // Return the prepared socket
   return sockfd;
 }
+
+int tap_alloc(char * ifname) {
+    struct ifreq ifr;
+    int fd, err;
+
+    if( (fd = open("/dev/net/tun", O_RDWR)) < 0 ) {
+      perror("Open tun");
+      return -1;
+    }
+
+    memset(&ifr, 0, sizeof(ifr));
+
+    /* Flags: IFF_TUN   - TUN device (no Ethernet headers)
+     *        IFF_TAP   - TAP device
+     *
+     *        IFF_NO_PI - Do not provide packet information
+     */
+    ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+    if( *ifname ) {
+       strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
+    }
+
+    if( (err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ){
+       close(fd);
+       return err;
+    }
+
+    strcpy(ifname, ifr.ifr_name);
+    return fd;
+}
diff --git a/src/socket.h b/src/socket.h
@@ -5,6 +5,7 @@
 extern "C" {
 #endif
 
+int tap_alloc(char * ifname);
 int sockraw_open(char * ifname);
 int iface_idx(int sockfd, char * ifname);
 
diff --git a/test.ini b/test.ini
@@ -3,10 +3,8 @@
 ; eth0 = backup, eth1 = primary
 [bond0]
 mode=active-backup
-interface=enp0s13f0u1c2
+interface=docker0
 weight=10
-interface=enp0s13f0u2c2
-weight=25
 
 ; ; broadcast everything on all interfaces
 ; [bond1]