diff options
Diffstat (limited to 'networking/udhcp/arpping.c')
| -rw-r--r-- | networking/udhcp/arpping.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/networking/udhcp/arpping.c b/networking/udhcp/arpping.c index b10bff651..fa0989d0f 100644 --- a/networking/udhcp/arpping.c +++ b/networking/udhcp/arpping.c @@ -41,7 +41,11 @@ enum { /* Returns 1 if no reply received */ -int FAST_FUNC arpping(uint32_t test_ip, uint32_t from_ip, uint8_t *from_mac, const char *interface) +int FAST_FUNC arpping(uint32_t test_ip, + const uint8_t *safe_mac, + uint32_t from_ip, + uint8_t *from_mac, + const char *interface) { int timeout_ms; struct pollfd pfd[1]; @@ -73,7 +77,7 @@ int FAST_FUNC arpping(uint32_t test_ip, uint32_t from_ip, uint8_t *from_mac, con arp.operation = htons(ARPOP_REQUEST); /* ARP op code */ memcpy(arp.sHaddr, from_mac, 6); /* source hardware address */ memcpy(arp.sInaddr, &from_ip, sizeof(from_ip)); /* source IP address */ - /* tHaddr is zero-fiiled */ /* target hardware address */ + /* tHaddr is zero-filled */ /* target hardware address */ memcpy(arp.tInaddr, &test_ip, sizeof(test_ip)); /* target IP address */ memset(&addr, 0, sizeof(addr)); @@ -98,13 +102,24 @@ int FAST_FUNC arpping(uint32_t test_ip, uint32_t from_ip, uint8_t *from_mac, con r = read(s, &arp, sizeof(arp)); if (r < 0) break; + + //bb_error_msg("sHaddr %02x:%02x:%02x:%02x:%02x:%02x", + // arp.sHaddr[0], arp.sHaddr[1], arp.sHaddr[2], + // arp.sHaddr[3], arp.sHaddr[4], arp.sHaddr[5]); + if (r >= ARP_MSG_SIZE && arp.operation == htons(ARPOP_REPLY) /* don't check it: Linux doesn't return proper tHaddr (fixed in 2.6.24?) */ /* && memcmp(arp.tHaddr, from_mac, 6) == 0 */ && *((uint32_t *) arp.sInaddr) == test_ip ) { - rv = 0; + /* if ARP source MAC matches safe_mac + * (which is client's MAC), then it's not a conflict + * (client simply already has this IP and replies to ARPs!) + */ + if (!safe_mac || memcmp(safe_mac, arp.sHaddr, 6) != 0) + rv = 0; + //else bb_error_msg("sHaddr == safe_mac"); break; } } |