The interface may have been recreated or the mac address was changed. In this situations socket has to be recreated to avoid proplems with the link-local IPv6 address and the scope_id (interface id). These properties are polled and checked every 60 seconds and the appropriate measures are taken when an error/change occurs. Signed-off-by: Sven Eckelmann &lt;sven(a)open-mesh.com&gt; --- alfred.h | 3 +++ server.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 68 insertions(+) diff --git a/alfred.h b/alfred.h index ba2e416..e3b6d86 100644 --- a/alfred.h +++ b/alfred.h @@ -31,6 +31,7 @@ #include "packet.h" #define ALFRED_INTERVAL 10 +#define ALFRED_IF_CHECK_INTERVAL 60 #define ALFRED_REQUEST_TIMEOUT 10 #define ALFRED_SERVER_TIMEOUT 60 #define ALFRED_DATA_TIMEOUT 600 @@ -102,6 +103,8 @@ struct globals { int netsock; int unix_sock; + struct timespec if_check; + struct hashtable_t *server_hash; struct hashtable_t *data_hash; struct hashtable_t *transaction_hash; diff --git a/server.c b/server.c index fd8572b..fdd97d4 100644 --- a/server.c +++ b/server.c @@ -20,14 +20,19 @@ */ #include <errno.h> +#include <inttypes.h> #include <net/ethernet.h> +#include <net/if.h> #include <stddef.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/select.h> +#include <sys/socket.h> +#include <sys/ioctl.h> #include <sys/time.h> +#include <unistd.h> #include <time.h> #include "alfred.h" #include "batadv_query.h" @@ -212,6 +217,64 @@ static int purge_data(struct globals *globals) return 0; } +static void check_if_socket(struct globals *globals) +{ + struct timespec now, diff; + int sock; + struct ifreq ifr; + + clock_gettime(CLOCK_MONOTONIC, &now); + time_diff(&now, &globals->if_check, &diff); + + if (diff.tv_sec < ALFRED_IF_CHECK_INTERVAL) + return; + + globals->if_check = now; + + if (globals->netsock < 0) + return; + + sock = socket(PF_INET6, SOCK_DGRAM, 0); + if (sock < 0) { + fprintf(stderr, "can't open socket: %s\n", strerror(errno)); + return; + } + + memset(&ifr, 0, sizeof(ifr)); + strncpy(ifr.ifr_name, globals->interface, IFNAMSIZ); + if (ioctl(sock, SIOCGIFINDEX, &ifr) == -1) { + fprintf(stderr, "can't get interface: %s, closing netsock\n", + strerror(errno)); + goto close; + } + + if (globals->scope_id != (uint32_t)ifr.ifr_ifindex) { + fprintf(stderr, + "iface index changed from %"PRIu32" to %d, closing netsock\n", + globals->scope_id, ifr.ifr_ifindex); + goto close; + } + + if (ioctl(sock, SIOCGIFHWADDR, &ifr) == -1) { + fprintf(stderr, "can't get MAC address: %s, closing netsock\n", + strerror(errno)); + goto close; + } + + if (memcmp(&globals->hwaddr, &ifr.ifr_hwaddr.sa_data, 6) != 0) { + fprintf(stderr, "iface mac changed, closing netsock\n"); + goto close; + } + + close(sock); + return; + +close: + netsock_close(globals->netsock); + globals->netsock = -1; + close(sock); +} + int alfred_server(struct globals *globals) { int maxsock, ret; @@ -237,6 +300,7 @@ int alfred_server(struct globals *globals) return -1; clock_gettime(CLOCK_MONOTONIC, &last_check); + globals->if_check = last_check; while (1) { clock_gettime(CLOCK_MONOTONIC, &now); @@ -297,6 +361,7 @@ int alfred_server(struct globals *globals) push_local_data(globals); } purge_data(globals); + check_if_socket(globals); } if (globals->netsock >= 0) -- 1.9.2