b3af65b95
Denys Vlasenko
2010-10-20
Subject
udhcpc: emit maxsize option in all non-NAK type packets
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networking/udhcp/dhcpc.c+90 -18
| @@ -346,31 +346,34 @@ static ALWAYS_INLINE uint32_t random_xid(void) | |
| /* Initialize the packet with the proper defaults */ | |
| static void init_packet(struct dhcp_packet *packet, char type) | |
| { | |
| + | /* Fill in: op, htype, hlen, cookie fields; message type option: */ |
| udhcp_init_header(packet, type); | |
| + | |
| + | packet->xid = random_xid(); |
| + | |
| memcpy(packet->chaddr, client_config.client_mac, 6); | |
| if (client_config.clientid) | |
| udhcp_add_binary_option(packet, client_config.clientid); | |
| + | } |
| + | |
| + | static void add_client_options(struct dhcp_packet *packet) |
| + | { |
| + | uint8_t c; |
| + | int i, end, len; |
| + | |
| + | udhcp_add_simple_option(packet, DHCP_MAX_SIZE, htons(IP_UDP_DHCP_SIZE)); |
| if (client_config.hostname) | |
| udhcp_add_binary_option(packet, client_config.hostname); | |
| if (client_config.fqdn) | |
| udhcp_add_binary_option(packet, client_config.fqdn); | |
| - | if (type != DHCPDECLINE |
| - | && type != DHCPRELEASE |
| - | && client_config.vendorclass |
| - | ) { |
| + | if (client_config.vendorclass) |
| udhcp_add_binary_option(packet, client_config.vendorclass); | |
| - | } |
| - | } |
| - | static void add_client_options(struct dhcp_packet *packet) |
| - | { |
| /* Add a "param req" option with the list of options we'd like to have | |
| * from stubborn DHCP servers. Pull the data from the struct in common.c. | |
| * No bounds checking because it goes towards the head of the packet. */ | |
| - | uint8_t c; |
| - | int end = udhcp_end_option(packet->options); |
| - | int i, len = 0; |
| - | |
| + | end = udhcp_end_option(packet->options); |
| + | len = 0; |
| for (i = 0; (c = dhcp_optflags[i].code) != 0; i++) { | |
| if (( (dhcp_optflags[i].flags & OPTION_REQ) | |
| && !client_config.no_default_options | |
| @@ -432,13 +435,20 @@ static int send_discover(uint32_t xid, uint32_t requested) | |
| { | |
| struct dhcp_packet packet; | |
| + | /* Fill in: op, htype, hlen, cookie, chaddr fields, |
| + | * random xid field (we override it below), |
| + | * client-id option (unless -C), message type option: |
| + | */ |
| init_packet(&packet, DHCPDISCOVER); | |
| + | |
| packet.xid = xid; | |
| if (requested) | |
| udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); | |
| - | /* Explicitly saying that we want RFC-compliant packets helps |
| - | * some buggy DHCP servers to NOT send bigger packets */ |
| - | udhcp_add_simple_option(&packet, DHCP_MAX_SIZE, htons(576)); |
| + | |
| + | /* Add options: maxsize, |
| + | * optionally: hostname, fqdn, vendorclass, |
| + | * "param req" option according to -O, options specified with -x |
| + | */ |
| add_client_options(&packet); | |
| bb_info_msg("Sending discover..."); | |
| @@ -454,10 +464,33 @@ static int send_select(uint32_t xid, uint32_t server, uint32_t requested) | |
| struct dhcp_packet packet; | |
| struct in_addr addr; | |
| + | /* |
| + | * RFC 2131 4.3.2 DHCPREQUEST message |
| + | * ... |
| + | * If the DHCPREQUEST message contains a 'server identifier' |
| + | * option, the message is in response to a DHCPOFFER message. |
| + | * Otherwise, the message is a request to verify or extend an |
| + | * existing lease. If the client uses a 'client identifier' |
| + | * in a DHCPREQUEST message, it MUST use that same 'client identifier' |
| + | * in all subsequent messages. If the client included a list |
| + | * of requested parameters in a DHCPDISCOVER message, it MUST |
| + | * include that list in all subsequent messages. |
| + | */ |
| + | /* Fill in: op, htype, hlen, cookie, chaddr fields, |
| + | * random xid field (we override it below), |
| + | * client-id option (unless -C), message type option: |
| + | */ |
| init_packet(&packet, DHCPREQUEST); | |
| + | |
| packet.xid = xid; | |
| udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); | |
| + | |
| udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server); | |
| + | |
| + | /* Add options: maxsize, |
| + | * optionally: hostname, fqdn, vendorclass, |
| + | * "param req" option according to -O, and options specified with -x |
| + | */ |
| add_client_options(&packet); | |
| addr.s_addr = requested; | |
| @@ -470,9 +503,33 @@ static int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr) | |
| { | |
| struct dhcp_packet packet; | |
| + | /* |
| + | * RFC 2131 4.3.2 DHCPREQUEST message |
| + | * ... |
| + | * DHCPREQUEST generated during RENEWING state: |
| + | * |
| + | * 'server identifier' MUST NOT be filled in, 'requested IP address' |
| + | * option MUST NOT be filled in, 'ciaddr' MUST be filled in with |
| + | * client's IP address. In this situation, the client is completely |
| + | * configured, and is trying to extend its lease. This message will |
| + | * be unicast, so no relay agents will be involved in its |
| + | * transmission. Because 'giaddr' is therefore not filled in, the |
| + | * DHCP server will trust the value in 'ciaddr', and use it when |
| + | * replying to the client. |
| + | */ |
| + | /* Fill in: op, htype, hlen, cookie, chaddr fields, |
| + | * random xid field (we override it below), |
| + | * client-id option (unless -C), message type option: |
| + | */ |
| init_packet(&packet, DHCPREQUEST); | |
| + | |
| packet.xid = xid; | |
| packet.ciaddr = ciaddr; | |
| + | |
| + | /* Add options: maxsize, |
| + | * optionally: hostname, fqdn, vendorclass, |
| + | * "param req" option according to -O, and options specified with -x |
| + | */ |
| add_client_options(&packet); | |
| bb_info_msg("Sending renew..."); | |
| @@ -489,9 +546,20 @@ static int send_decline(uint32_t xid, uint32_t server, uint32_t requested) | |
| { | |
| struct dhcp_packet packet; | |
| + | /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields, |
| + | * client-id option (unless -C), message type option: |
| + | */ |
| init_packet(&packet, DHCPDECLINE); | |
| + | |
| + | /* RFC 2131 says DHCPDECLINE's xid is randomly selected by client, |
| + | * but in case the server is buggy and wants DHCPDECLINE's xid |
| + | * to match the xid which started entire handshake, |
| + | * we use the same xid we used in initial DHCPDISCOVER: |
| + | */ |
| packet.xid = xid; | |
| + | /* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */ |
| udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); | |
| + | |
| udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server); | |
| bb_info_msg("Sending decline..."); | |
| @@ -504,8 +572,12 @@ static int send_release(uint32_t server, uint32_t ciaddr) | |
| { | |
| struct dhcp_packet packet; | |
| + | /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields, |
| + | * client-id option (unless -C), message type option: |
| + | */ |
| init_packet(&packet, DHCPRELEASE); | |
| - | packet.xid = random_xid(); |
| + | |
| + | /* DHCPRELEASE uses ciaddr, not "requested ip", to store IP being released */ |
| packet.ciaddr = ciaddr; | |
| udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server); | |
| @@ -1254,7 +1326,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) | |
| /* Ignore packets that aren't for us */ | |
| if (packet.hlen != 6 | |
| - | || memcmp(packet.chaddr, client_config.client_mac, 6) |
| + | || memcmp(packet.chaddr, client_config.client_mac, 6) != 0 |
| ) { | |
| //FIXME: need to also check that last 10 bytes are zero | |
| log1("chaddr does not match, ignoring packet"); // log2? | |
| @@ -1280,7 +1352,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) | |
| } | |
| /* it IS unaligned sometimes, don't "optimize" */ | |
| move_from_unaligned32(server_addr, temp); | |
| - | xid = packet.xid; |
| + | /*xid = packet.xid; - already is */ |
| requested_ip = packet.yiaddr; | |
| /* enter requesting state */ | |