mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-30 18:47:06 +00:00
100 lines
3.4 KiB
Diff
100 lines
3.4 KiB
Diff
--- 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);
|