diff options
Diffstat (limited to 'package/busybox/patches/241-udhcpc-oversized_packets.patch')
| -rw-r--r-- | package/busybox/patches/241-udhcpc-oversized_packets.patch | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/package/busybox/patches/241-udhcpc-oversized_packets.patch b/package/busybox/patches/241-udhcpc-oversized_packets.patch new file mode 100644 index 000000000..471d704a7 --- /dev/null +++ b/package/busybox/patches/241-udhcpc-oversized_packets.patch @@ -0,0 +1,99 @@ +--- a/networking/udhcp/packet.c ++++ b/networking/udhcp/packet.c +@@ -158,6 +158,11 @@ uint16_t FAST_FUNC udhcp_checksum(void * + return ~sum; + } + ++int udhcp_get_payload_len(struct dhcp_packet *dhcp_pkt) ++{ ++ return sizeof(struct dhcp_packet) - DHCP_OPTIONS_BUFSIZE + udhcp_end_option(dhcp_pkt->options) + sizeof(dhcp_pkt->options[0]); ++} ++ + /* Construct a ip/udp header for a packet, send packet */ + int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt, + uint32_t source_nip, int source_port, +@@ -166,10 +171,10 @@ int FAST_FUNC udhcp_send_raw_packet(stru + { + struct sockaddr_ll dest_sll; + struct ip_udp_dhcp_packet packet; +- unsigned padding; + int fd; + int result = -1; + const char *msg; ++ int p_len = udhcp_get_payload_len(dhcp_pkt); + + fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP)); + if (fd < 0) { +@@ -178,8 +183,8 @@ int FAST_FUNC udhcp_send_raw_packet(stru + } + + memset(&dest_sll, 0, sizeof(dest_sll)); +- memset(&packet, 0, offsetof(struct ip_udp_dhcp_packet, data)); +- packet.data = *dhcp_pkt; /* struct copy */ ++ memset(&packet, 0, sizeof(packet)); ++ memcpy(&(packet.data), dhcp_pkt, p_len); + + dest_sll.sll_family = AF_PACKET; + dest_sll.sll_protocol = htons(ETH_P_IP); +@@ -192,36 +197,24 @@ int FAST_FUNC udhcp_send_raw_packet(stru + goto ret_close; + } + +- /* We were sending full-sized DHCP packets (zero padded), +- * but some badly configured servers were seen dropping them. +- * Apparently they drop all DHCP packets >576 *ethernet* octets big, +- * whereas they may only drop packets >576 *IP* octets big +- * (which for typical Ethernet II means 590 octets: 6+6+2 + 576). +- * +- * In order to work with those buggy servers, +- * we truncate packets after end option byte. +- */ +- padding = DHCP_OPTIONS_BUFSIZE - 1 - udhcp_end_option(packet.data.options); +- + packet.ip.protocol = IPPROTO_UDP; + packet.ip.saddr = source_nip; + packet.ip.daddr = dest_nip; + packet.udp.source = htons(source_port); + packet.udp.dest = htons(dest_port); +- /* size, excluding IP header: */ +- packet.udp.len = htons(UDP_DHCP_SIZE - padding); +- /* for UDP checksumming, ip.len is set to UDP packet len */ ++ p_len += sizeof(packet.udp); ++ packet.udp.len = htons(p_len); + packet.ip.tot_len = packet.udp.len; +- packet.udp.check = udhcp_checksum(&packet, IP_UDP_DHCP_SIZE - padding); +- /* but for sending, it is set to IP packet len */ +- packet.ip.tot_len = htons(IP_UDP_DHCP_SIZE - padding); ++ p_len += sizeof(packet.ip); ++ packet.udp.check = udhcp_checksum(&packet, p_len); ++ packet.ip.tot_len = htons(p_len); + packet.ip.ihl = sizeof(packet.ip) >> 2; + packet.ip.version = IPVERSION; + packet.ip.ttl = IPDEFTTL; + packet.ip.check = udhcp_checksum(&packet.ip, sizeof(packet.ip)); + + udhcp_dump_packet(dhcp_pkt); +- result = sendto(fd, &packet, IP_UDP_DHCP_SIZE - padding, /*flags:*/ 0, ++ result = sendto(fd, &packet, p_len, /*flags:*/ 0, + (struct sockaddr *) &dest_sll, sizeof(dest_sll)); + msg = "sendto"; + ret_close: +@@ -239,7 +232,6 @@ int FAST_FUNC udhcp_send_kernel_packet(s + uint32_t dest_nip, int dest_port) + { + struct sockaddr_in client; +- unsigned padding; + int fd; + int result = -1; + const char *msg; +@@ -270,9 +262,7 @@ int FAST_FUNC udhcp_send_kernel_packet(s + } + + udhcp_dump_packet(dhcp_pkt); +- +- padding = DHCP_OPTIONS_BUFSIZE - 1 - udhcp_end_option(dhcp_pkt->options); +- result = safe_write(fd, dhcp_pkt, DHCP_SIZE - padding); ++ result = safe_write(fd, dhcp_pkt, udhcp_get_payload_len(dhcp_pkt)); + msg = "write"; + ret_close: + close(fd); |