add_option_string(packet->options, client_config.hostname);
if (client_config.fqdn)
add_option_string(packet->options, client_config.fqdn);
- add_option_string(packet->options, client_config.vendorclass);
+ if ((type != DHCPDECLINE) && (type != DHCPRELEASE))
+ add_option_string(packet->options, client_config.vendorclass);
}
/* Add a parameter request list for stubborn DHCP servers. Pull the data
* from the struct in options.c. Don't do bounds checking here because it
* goes towards the head of the packet. */
-static void add_requests(struct dhcpMessage *packet)
+static void add_param_req_option(struct dhcpMessage *packet)
{
+ uint8_t c;
int end = end_option(packet->options);
int i, len = 0;
packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
- for (i = 0; dhcp_options[i].code; i++)
- if (dhcp_options[i].flags & OPTION_REQ)
- packet->options[end + OPT_DATA + len++] = dhcp_options[i].code;
+ for (i = 0; (c = dhcp_options[i].code) != 0; i++) {
+ if ((dhcp_options[i].flags & OPTION_REQ)
+ || (client_config.opt_mask[c >> 3] & (1 << (c & 7)))
+ ) {
+ packet->options[end + OPT_DATA + len] = c;
+ len++;
+ }
+ }
packet->options[end + OPT_LEN] = len;
packet->options[end + OPT_DATA + len] = DHCP_END;
-
}
+
#if ENABLE_FEATURE_UDHCPC_ARPING
/* Unicast a DHCP decline message */
-int send_decline(uint32_t xid, uint32_t server)
+int send_decline(uint32_t xid, uint32_t server, uint32_t requested)
{
struct dhcpMessage packet;
init_packet(&packet, DHCPDECLINE);
packet.xid = xid;
- add_requests(&packet);
+ add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
+ add_simple_option(packet.options, DHCP_SERVER_ID, server);
bb_info_msg("Sending decline...");
- return udhcp_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
+ return udhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
}
#endif
if (requested)
add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
- add_requests(&packet);
+ /* Explicitly saying that we want RFC-compliant packets helps
+ * some buggy DHCP servers to NOT send bigger packets */
+ add_simple_option(packet.options, DHCP_MAX_SIZE, htons(576));
+ add_param_req_option(&packet);
bb_info_msg("Sending discover...");
- return udhcp_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
+ return udhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
}
add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
add_simple_option(packet.options, DHCP_SERVER_ID, server);
- add_requests(&packet);
+ add_param_req_option(&packet);
addr.s_addr = requested;
bb_info_msg("Sending select for %s...", inet_ntoa(addr));
- return udhcp_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
+ return udhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
}
packet.xid = xid;
packet.ciaddr = ciaddr;
- add_requests(&packet);
+ add_param_req_option(&packet);
bb_info_msg("Sending renew...");
if (server)
- return udhcp_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
+ return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
- return udhcp_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
+ return udhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
}
packet.xid = random_xid();
packet.ciaddr = ciaddr;
- add_simple_option(packet.options, DHCP_REQUESTED_IP, ciaddr);
add_simple_option(packet.options, DHCP_SERVER_ID, server);
bb_info_msg("Sending release...");
- return udhcp_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
+ return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
}
-/* return -1 on errors that are fatal for the socket, -2 for those that aren't */
+/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
int get_raw_packet(struct dhcpMessage *payload, int fd)
{
int bytes;
struct udp_dhcp_packet packet;
- uint32_t source, dest;
uint16_t check;
- memset(&packet, 0, sizeof(struct udp_dhcp_packet));
- bytes = read(fd, &packet, sizeof(struct udp_dhcp_packet));
+ memset(&packet, 0, sizeof(packet));
+ bytes = safe_read(fd, &packet, sizeof(packet));
if (bytes < 0) {
DEBUG("Cannot read on raw listening socket - ignoring");
sleep(1); /* possible down interface, looping condition */
- return -1;
+ return bytes; /* returns -1 */
}
- if (bytes < (int) (sizeof(struct iphdr) + sizeof(struct udphdr))) {
- DEBUG("Message too short, ignoring");
+ if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
+ DEBUG("Packet is too short, ignoring");
return -2;
}
if (bytes < ntohs(packet.ip.tot_len)) {
- DEBUG("Truncated packet");
+ /* packet is bigger than sizeof(packet), we did partial read */
+ DEBUG("Oversized packet, ignoring");
return -2;
}
/* ignore any extra garbage bytes */
bytes = ntohs(packet.ip.tot_len);
- /* Make sure its the right packet for us, and that it passes sanity checks */
+ /* make sure its the right packet for us, and that it passes sanity checks */
if (packet.ip.protocol != IPPROTO_UDP || packet.ip.version != IPVERSION
|| packet.ip.ihl != (sizeof(packet.ip) >> 2)
|| packet.udp.dest != htons(CLIENT_PORT)
- || bytes > (int) sizeof(struct udp_dhcp_packet)
+ /* || bytes > (int) sizeof(packet) - can't happen */
|| ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
) {
DEBUG("Unrelated/bogus packet");
return -2;
}
- /* check IP checksum */
+ /* verify IP checksum */
check = packet.ip.check;
packet.ip.check = 0;
- if (check != udhcp_checksum(&(packet.ip), sizeof(packet.ip))) {
- DEBUG("bad IP header checksum, ignoring");
- return -1;
+ if (check != udhcp_checksum(&packet.ip, sizeof(packet.ip))) {
+ DEBUG("Bad IP header checksum, ignoring");
+ return -2;
}
- /* verify the UDP checksum by replacing the header with a pseudo header */
- source = packet.ip.saddr;
- dest = packet.ip.daddr;
+ /* verify UDP checksum. IP header has to be modified for this */
+ memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
+ /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
+ packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
check = packet.udp.check;
packet.udp.check = 0;
- memset(&packet.ip, 0, sizeof(packet.ip));
-
- packet.ip.protocol = IPPROTO_UDP;
- packet.ip.saddr = source;
- packet.ip.daddr = dest;
- packet.ip.tot_len = packet.udp.len; /* cheat on the psuedo-header */
if (check && check != udhcp_checksum(&packet, bytes)) {
bb_error_msg("packet with bad UDP checksum received, ignoring");
return -2;
}
- memcpy(payload, &(packet.data), bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
+ memcpy(payload, &packet.data, bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
if (payload->cookie != htonl(DHCP_MAGIC)) {
- bb_error_msg("received bogus message (bad magic) - ignoring");
+ bb_error_msg("received bogus message (bad magic), ignoring");
return -2;
}
- DEBUG("oooooh!!! got some!");
+ DEBUG("Got valid DHCP packet");
return bytes - (sizeof(packet.ip) + sizeof(packet.udp));
}
projects / oweals / busybox.git / blobdiff