firedancer-io · ripatel-fd · Feb 13, 2025 · Feb 13, 2025
diff --git a/src/app/fdctl/config.c b/src/app/fdctl/config.c
@@ -526,12 +526,20 @@ fdctl_cfg_from_env( int *      pargc,
   config->is_live_cluster = cluster != FD_CLUSTER_UNKNOWN;
 
   if( FD_UNLIKELY( config->development.netns.enabled ) ) {
-    /* not currently supporting multihoming on netns */
-    if( FD_UNLIKELY( strcmp( config->development.netns.interface0, config->tiles.net.interface ) ) )
+    if( !strcmp( config->tiles.net.interface, "" ) ) {
+      memcpy( config->tiles.net.interface, config->development.netns.interface0, sizeof(config->tiles.net.interface) );
+    }
+
+    if( !strcmp( config->development.pktgen.fake_dst_ip, "" ) ) {
+      memcpy( config->development.pktgen.fake_dst_ip, config->development.netns.interface1_addr, sizeof(config->development.netns.interface1_addr) );
+    }
+
+    if( FD_UNLIKELY( strcmp( config->development.netns.interface0, config->tiles.net.interface ) ) ) {
       FD_LOG_ERR(( "netns interface and firedancer interface are different. If you are using the "
                    "[development.netns] functionality to run Firedancer in a network namespace "
                    "for development, the configuration file must specify that "
-                   "[development.netns.interface0] is the same as [net.interface]" ));
+                   "[development.netns.interface0] is the same as [tiles.net.interface]" ));
+    }
 
     if( FD_UNLIKELY( !fd_cstr_to_ip4_addr( config->development.netns.interface0_addr, &config->tiles.net.ip_addr ) ) )
       FD_LOG_ERR(( "configuration specifies invalid netns IP address `%s`", config->development.netns.interface0_addr ));

diff --git a/src/app/fdctl/config.h b/src/app/fdctl/config.h
@@ -175,10 +175,10 @@ struct fdctl_config {
       int  enabled;
       char interface0     [ 16 ];
       char interface0_mac [ 32 ];
-      char interface0_addr[ 32 ];
+      char interface0_addr[ 16 ];
       char interface1     [ 16 ];
       char interface1_mac [ 32 ];
-      char interface1_addr[ 32 ];
+      char interface1_addr[ 16 ];
     } netns;
 
     struct {

diff --git a/src/app/fdctl/netconf.c b/src/app/fdctl/netconf.c
@@ -50,11 +50,7 @@ netconf_cmd_fn( args_t *   args,
   fd_fib4_fprintf( fib4_local, stdout );
   fd_fib4_leave( fib4_local );
 
-  char if_name[ IF_NAMESIZE ] = "???";
-  if( FD_UNLIKELY( !if_indextoname( tile->netlink.neigh_if_idx, if_name ) ) ) {
-    memcpy( if_name, "???", 4 );
-  }
-  printf( "\nNEIGHBOR TABLE (%u-%s)\n\n", tile->netlink.neigh_if_idx, if_name );
+  printf( "\nNEIGHBOR TABLE (%.16s)\n\n", tile->netlink.neigh_if );
   fd_neigh4_hmap_t neigh4[1];
   FD_TEST( fd_neigh4_hmap_join( neigh4, fd_topo_obj_laddr( topo, tile->netlink.neigh4_obj_id ), fd_topo_obj_laddr( topo, tile->netlink.neigh4_ele_obj_id ) ) );
   fd_neigh4_hmap_fprintf( neigh4, stdout );

diff --git a/src/app/fdctl/run/run.c b/src/app/fdctl/run/run.c
@@ -687,27 +687,29 @@ extern configure_stage_t fd_cfg_stage_ethtool_loopback;
 extern configure_stage_t fd_cfg_stage_sysctl;
 
 void
-fdctl_check_configure( config_t * const config ) {
+fdctl_check_configure( config_t * config ) {
   configure_result_t check = fd_cfg_stage_hugetlbfs.check( config );
   if( FD_UNLIKELY( check.result!=CONFIGURE_OK ) )
     FD_LOG_ERR(( "Huge pages are not configured correctly: %s. You can run `fdctl configure init hugetlbfs` "
                  "to create the mounts correctly. This must be done after every system restart before running "
                  "Firedancer.", check.message ));
 
-  check = fd_cfg_stage_ethtool_channels.check( config );
-  if( FD_UNLIKELY( check.result!=CONFIGURE_OK ) )
-    FD_LOG_ERR(( "Network %s. You can run `fdctl configure init ethtool-channels` to set the number of channels on the "
-                 "network device correctly.", check.message ));
-
-  check = fd_cfg_stage_ethtool_gro.check( config );
-  if( FD_UNLIKELY( check.result!=CONFIGURE_OK ) )
-    FD_LOG_ERR(( "Network %s. You can run `fdctl configure init ethtool-gro` to disable generic-receive-offload "
-                 "as required.", check.message ));
-
-  check = fd_cfg_stage_ethtool_loopback.check( config );
-  if( FD_UNLIKELY( check.result!=CONFIGURE_OK ) )
-    FD_LOG_ERR(( "Network %s. You can run `fdctl configure init ethtool-loopback` to disable tx-udp-segmentation "
-                 "on the loopback device.", check.message ));
+  if( FD_LIKELY( !config->development.netns.enabled ) ) {
+    check = fd_cfg_stage_ethtool_channels.check( config );
+    if( FD_UNLIKELY( check.result!=CONFIGURE_OK ) )
+      FD_LOG_ERR(( "Network %s. You can run `fdctl configure init ethtool-channels` to set the number of channels on the "
+                  "network device correctly.", check.message ));
+
+    check = fd_cfg_stage_ethtool_gro.check( config );
+    if( FD_UNLIKELY( check.result!=CONFIGURE_OK ) )
+      FD_LOG_ERR(( "Network %s. You can run `fdctl configure init ethtool-gro` to disable generic-receive-offload "
+                  "as required.", check.message ));
+
+    check = fd_cfg_stage_ethtool_loopback.check( config );
+    if( FD_UNLIKELY( check.result!=CONFIGURE_OK ) )
+      FD_LOG_ERR(( "Network %s. You can run `fdctl configure init ethtool-loopback` to disable tx-udp-segmentation "
+                  "on the loopback device.", check.message ));
+  }
 
   check = fd_cfg_stage_sysctl.check( config );
   if( FD_UNLIKELY( check.result!=CONFIGURE_OK ) )
@@ -716,8 +718,8 @@ fdctl_check_configure( config_t * const config ) {
 }
 
 void
-run_firedancer_init( config_t * const config,
-                     int              init_workspaces ) {
+run_firedancer_init( config_t * config,
+                     int        init_workspaces ) {
   struct stat st;
   int err = stat( config->consensus.identity_path, &st );
   if( FD_UNLIKELY( -1==err && errno==ENOENT ) ) FD_LOG_ERR(( "[consensus.identity_path] key does not exist `%s`. You can generate an identity key at this path by running `fdctl keys new identity --config <toml>`", config->consensus.identity_path ));
@@ -734,6 +736,18 @@ run_firedancer_init( config_t * const config,
   initialize_stacks( config );
 }
 
+void
+fdctl_setup_netns( config_t * config ) {
+  if( config->development.netns.enabled ) {
+    enter_network_namespace( config->tiles.net.interface );
+    close_network_namespace_original_fd();
+  }
+
+  fd_cfg_stage_ethtool_channels.init( config );
+  fd_cfg_stage_ethtool_gro     .init( config );
+  fd_cfg_stage_ethtool_loopback.init( config );
+}
+
 /* The boot sequence is a little bit involved...
 
    A process tree is created that looks like,

diff --git a/src/app/fdctl/run/run.h b/src/app/fdctl/run/run.h
@@ -32,6 +32,9 @@ void
 run_firedancer_init( config_t * const config,
                      int              init_workspaces );
 
+void
+fdctl_setup_netns( config_t * config );
+
 void
 run_firedancer( config_t * const config,
                 int              parent_pipefd,

diff --git a/src/app/fdctl/utility.c b/src/app/fdctl/utility.c
@@ -11,7 +11,9 @@
 #include <fcntl.h>
 #include <sched.h>
 #include <dirent.h>
+#include <net/if.h> /* IFF_UP */
 
+#include <sys/ioctl.h> /* ioctl(2) */
 #include <sys/mman.h> /* for mprotect */
 #include <sys/stat.h>
 #include <sys/socket.h>
@@ -40,6 +42,16 @@ enter_network_namespace( const char * interface ) {
     FD_LOG_ERR(( "failed to enter network namespace `%s` (%i-%s)", path, errno, fd_io_strerror( errno ) ));
   int ret = close( fd );
   if( FD_UNLIKELY( ret ) ) FD_LOG_ERR(( "enter_network_namespace %d (%i-%s)", ret, errno, fd_io_strerror( errno ) ));
+
+  /* `ip link set dev lo up`
+     Done via the ioctl API for simplicity.  Requires a dummy socket. */
+  int ifreq_fd = socket( AF_INET, SOCK_DGRAM, 0 );
+  if( FD_UNLIKELY( ifreq_fd<0 ) ) FD_LOG_ERR(( "socket(AF_INET,SOCK_DGRAM,0) failed (%i-%s)", errno, fd_io_strerror( errno ) ));
+  struct ifreq ifr = { .ifr_name = "lo" };
+  if( FD_UNLIKELY( ioctl( ifreq_fd, SIOCGIFFLAGS, &ifr ) ) ) FD_LOG_ERR(( "ioctl(SIOCGIFFLAGS,\"lo\") failed (%i-%s)", errno, fd_io_strerror( errno ) ));
+  ifr.ifr_flags |= (IFF_UP|IFF_RUNNING);
+  if( FD_UNLIKELY( ioctl( ifreq_fd, SIOCSIFFLAGS, &ifr ) ) ) FD_LOG_ERR(( "ioctl(SIOCGIFFLAGS,\"lo\",IFF_UP|IFF_RUNNING) failed (%i-%s)", errno, fd_io_strerror( errno ) ));
+  if( FD_UNLIKELY( close( ifreq_fd ) ) ) FD_LOG_ERR(( "failed to close dummy UDP socket (%i-%s)", errno, fd_io_strerror( errno ) ));
 }
 
 void

diff --git a/src/app/fddev/bench.c b/src/app/fddev/bench.c
@@ -169,6 +169,7 @@ bench_cmd_fn( args_t *         args,
   update_config_for_dev( config );
 
   run_firedancer_init( config, 1 );
+  fdctl_setup_netns( config );
 
   fd_xdp_fds_t fds = fd_topo_install_xdp( &config->topo );
   (void)fds;

diff --git a/src/app/fddev/dev.c b/src/app/fddev/dev.c
@@ -150,6 +150,7 @@ run_firedancer_threaded( config_t * config , int init_workspaces) {
   fd_topo_print_log( 0, &config->topo );
 
   run_firedancer_init( config, init_workspaces );
+  fdctl_setup_netns( config );
 
   if( FD_UNLIKELY( config->development.debug_tile ) ) {
     fd_log_private_shared_lock[ 1 ] = 1;

diff --git a/src/app/fddev/pktgen.c b/src/app/fddev/pktgen.c
@@ -83,6 +83,7 @@ pktgen_cmd_fn( args_t *         args,
   /* FIXME this allocates lots of memory unnecessarily */
   initialize_workspaces( config );
   initialize_stacks( config );
+  fdctl_setup_netns( config );
   (void)fd_topo_install_xdp( &config->topo );;
   fd_topo_join_workspaces( &config->topo, FD_SHMEM_JOIN_MODE_READ_WRITE );
 

diff --git a/src/ballet/http/fd_http_server.c b/src/ballet/http/fd_http_server.c
@@ -4,6 +4,7 @@
 #include "picohttpparser.h"
 #include "fd_sha1.h"
 #include "../base64/fd_base64.h"
+#include "../../util/net/fd_ip4.h"
 
 #include <stdarg.h>
 #include <stdio.h>
@@ -282,8 +283,12 @@ fd_http_server_listen( fd_http_server_t * http,
     .sin_addr.s_addr = address,
   };
 
-  if( FD_UNLIKELY( -1==bind( sockfd, fd_type_pun( &addr ), sizeof( addr ) ) ) ) FD_LOG_ERR(( "bind failed (%i-%s)", errno, strerror( errno ) ));
-  if( FD_UNLIKELY( -1==listen( sockfd, (int)http->max_conns ) ) ) FD_LOG_ERR(( "listen failed (%i-%s)", errno, strerror( errno ) ));
+  if( FD_UNLIKELY( -1==bind( sockfd, fd_type_pun( &addr ), sizeof( addr ) ) ) ) {
+    FD_LOG_ERR(( "bind(%i,AF_INET," FD_IP4_ADDR_FMT ":%u) failed (%i-%s)",
+                 sockfd, FD_IP4_ADDR_FMT_ARGS( address ), port,
+                 errno, fd_io_strerror( errno ) ));
+  }
+  if( FD_UNLIKELY( -1==listen( sockfd, (int)http->max_conns ) ) ) FD_LOG_ERR(( "listen failed (%i-%s)", errno, fd_io_strerror( errno ) ));
 
   http->socket_fd = sockfd;
   http->pollfds[ http->max_conns+http->max_ws_conns ].fd = http->socket_fd;

diff --git a/src/disco/netlink/fd_netlink_tile.c b/src/disco/netlink/fd_netlink_tile.c
@@ -48,8 +48,6 @@ fd_netlink_topo_create( fd_topo_tile_t *            netlink_tile,
 
   /* Configure neighbor hashmap: Open addressed hashmap with 3.0 sparsity
      factor and 16 long probe chain */
-  uint  const neigh_if_idx    = if_nametoindex( config->tiles.net.interface );
-  if( FD_UNLIKELY( !neigh_if_idx ) ) FD_LOG_ERR(( "if_nametoindex(%s) failed (%i-%s)", config->tiles.net.interface, errno, fd_io_strerror( errno ) ));
   ulong const neigh_ele_max   = fd_ulong_pow2_up( 3UL * config->tiles.netlink.max_neighbors );
   ulong const neigh_ele_align = alignof(fd_neigh4_entry_t);
   ulong const neigh_ele_fp    = neigh_ele_max * sizeof(fd_neigh4_entry_t);
@@ -67,7 +65,7 @@ fd_netlink_topo_create( fd_topo_tile_t *            netlink_tile,
   netlink_tile->netlink.netdev_dbl_buf_obj_id = netdev_dbl_buf_obj->id;
   netlink_tile->netlink.fib4_main_obj_id      = fib4_main_obj->id;
   netlink_tile->netlink.fib4_local_obj_id     = fib4_local_obj->id;
-  netlink_tile->netlink.neigh_if_idx          = neigh_if_idx;
+  memcpy( netlink_tile->netlink.neigh_if, config->tiles.net.interface, sizeof(netlink_tile->netlink.neigh_if) );
   netlink_tile->netlink.neigh4_obj_id         = neigh4_obj->id;
   netlink_tile->netlink.neigh4_ele_obj_id     = neigh4_ele_obj->id;
 }
@@ -135,10 +133,13 @@ privileged_init( fd_topo_t *      topo,
     FD_LOG_ERR(( "Topology contains more than one netlink tile" ));
   }
 
+  uint const neigh_if_idx = if_nametoindex( tile->netlink.neigh_if );
+  if( FD_UNLIKELY( !neigh_if_idx ) ) FD_LOG_ERR(( "if_nametoindex(%.16s) failed (%i-%s)", tile->netlink.neigh_if, errno, fd_io_strerror( errno ) ));
+
   fd_netlink_tile_ctx_t * ctx = fd_topo_obj_laddr( topo, tile->tile_obj_id );
   fd_memset( ctx, 0, sizeof(fd_netlink_tile_ctx_t) );
   ctx->magic = FD_NETLINK_TILE_CTX_MAGIC;
-  ctx->neigh4_ifidx = tile->netlink.neigh_if_idx;
+  ctx->neigh4_ifidx = neigh_if_idx;
 
   if( FD_UNLIKELY( !fd_netlink_init( ctx->nl_monitor, 1000U ) ) ) {
     FD_LOG_ERR(( "Failed to connect to rtnetlink" ));

diff --git a/src/disco/topo/fd_topo.h b/src/disco/topo/fd_topo.h
@@ -153,7 +153,7 @@ typedef struct {
       ulong netdev_dbl_buf_obj_id; /* dbl_buf containing netdev_tbl */
       ulong fib4_main_obj_id;      /* fib4 containing main route table */
       ulong fib4_local_obj_id;     /* fib4 containing local route table */
-      uint  neigh_if_idx;          /* neigh4 interface index */
+      char  neigh_if[ 16 ];        /* neigh4 interface name */
       ulong neigh4_obj_id;         /* neigh4 hash map header */
       ulong neigh4_ele_obj_id;     /* neigh4 hash map slots */
     } netlink;

diff --git a/src/waltz/mib/fd_netdev_netlink.c b/src/waltz/mib/fd_netdev_netlink.c
@@ -120,13 +120,14 @@ fd_netdev_netlink_load_table( fd_netdev_tbl_join_t * tbl,
       switch( rat->rta_type ) {
 
       case IFLA_IFNAME:
-        if( FD_UNLIKELY( rta_sz==0 || rta_sz>=IFNAMSIZ ) ) {
+        /* Includes trailing zero */
+        if( FD_UNLIKELY( rta_sz==0 || rta_sz>IFNAMSIZ ) ) {
           FD_LOG_WARNING(( "Error reading interface table: IFLA_IFNAME has unsupported size %lu", rta_sz ));
           err = EPROTO;
           goto fail;
         }
         memcpy( netdev->name, rta, rta_sz );
-        netdev->name[ rta_sz ] = '\0';
+        netdev->name[ rta_sz-1 ] = '\0';
         break;
 
       case IFLA_ADDRESS: