diff options
| author | Patrik Flykt <patrik.flykt@linux.intel.com> | 2013-12-09 23:43:28 +0200 |
|---|---|---|
| committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2013-12-12 11:43:34 -0500 |
| commit | 564ba3b0efbcaf8d5881dbfb80d3c0b174ccaba5 (patch) | |
| tree | a9f327d881f32e503eea6d2f4992aab654e18179 | |
| parent | e2dfc79f0624dfbfa30156880b31b13510405f54 (diff) | |
dhcp: Add maximum message size option
Add maximum message size option to keep some DHCP server implementations
from sending too big messages. See ConnMan commit
0c5c862749c05193cf4c513628328c6db02b5222.
| -rw-r--r-- | src/libsystemd-dhcp/dhcp-client.c | 12 | ||||
| -rw-r--r-- | src/libsystemd-dhcp/dhcp-protocol.h | 1 |
2 files changed, 13 insertions, 0 deletions
diff --git a/src/libsystemd-dhcp/dhcp-client.c b/src/libsystemd-dhcp/dhcp-client.c index 4980174e00..b1bdd38593 100644 --- a/src/libsystemd-dhcp/dhcp-client.c +++ b/src/libsystemd-dhcp/dhcp-client.c @@ -186,6 +186,7 @@ static int client_packet_init(sd_dhcp_client *client, uint8_t type, uint8_t **opt, size_t *optlen) { int err; + be16_t max_size; *opt = (uint8_t *)(message + 1); @@ -229,6 +230,17 @@ static int client_packet_init(sd_dhcp_client *client, uint8_t type, client->req_opts); if (err < 0) return err; + + /* Some DHCP servers will send bigger DHCP packets than the + defined default size unless the Maximum Messge Size option + is explicitely set */ + max_size = htobe16(DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE + + DHCP_CLIENT_MIN_OPTIONS_SIZE); + err = dhcp_option_append(opt, optlen, + DHCP_OPTION_MAXIMUM_MESSAGE_SIZE, + 2, &max_size); + if (err < 0) + return err; } return 0; diff --git a/src/libsystemd-dhcp/dhcp-protocol.h b/src/libsystemd-dhcp/dhcp-protocol.h index 95c4f4ea66..f5f490d8b9 100644 --- a/src/libsystemd-dhcp/dhcp-protocol.h +++ b/src/libsystemd-dhcp/dhcp-protocol.h @@ -111,6 +111,7 @@ enum { DHCP_OPTION_MESSAGE_TYPE = 53, DHCP_OPTION_SERVER_IDENTIFIER = 54, DHCP_OPTION_PARAMETER_REQUEST_LIST = 55, + DHCP_OPTION_MAXIMUM_MESSAGE_SIZE = 57, DHCP_OPTION_CLIENT_IDENTIFIER = 61, DHCP_OPTION_END = 255, }; |