busybox-w32/networking/udhcp/common.c, branch cron_changes

udhcpd: optional BOOTP support

2023-06-12T11:22:47+00:00

from Adam Goldman This patch makes udhcpd respond correctly to queries from BOOTP clients. It contains the following changes: The end field, or DHCP_END option, is required in DHCP requests but optional in BOOTP requests. However, we still send an end field in all replies, because some BOOTP clients expect one in replies even if they didn't send one in the request. Requests without a DHCP_MESSAGE_TYPE are recognized as BOOTP requests and handled appropriately, instead of being discarded. We still require an RFC 1048 options field, but we allow it to be empty. Since a BOOTP client will keep using the assigned IP forever, we only send a BOOTP reply if a static lease exists for that client. BOOTP replies shouldn't contain DHCP_* options, so we omit them if there was no DHCP_MESSAGE_TYPE in the request. Options other than DHCP_* options are still sent. The options field of a BOOTP reply must be exactly 64 bytes. If we construct a reply with more than 64 bytes of options, we give up and log an error instead of sending it. udhcp_send_raw_packet already pads the options field to 64 bytes if it is too short. This implementation has been tested against an HP PA-RISC client. function old new delta .rodata 105247 105321 +74 udhcpd_main 1520 1591 +71 send_offer 419 470 +51 init_packet 81 97 +16 udhcp_init_header 75 88 +13 udhcp_scan_options 192 203 +11 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 6/0 up/down: 236/0) Total: 236 bytes Signed-off-by: Denys Vlasenko

: slap on a few ALIGN where appropriate

2022-02-06T18:53:10+00:00

The result of looking at "grep -F -B2 '*fill*' busybox_unstripped.map" function old new delta .rodata 108586 108460 -126 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-126) Total: -126 bytes text data bss dec hex filename 970412 4219 1848 976479 ee65f busybox_old 970286 4219 1848 976353 ee5e1 busybox_unstripped Signed-off-by: Denys Vlasenko

udhcpc6: fix udhcp_find_option to actually find DHCP6 options

2021-12-12T16:13:54+00:00

udhcp_insert_new_option treats code for IPv6 as follows: new->data[D6_OPT_CODE] = code >> 8; new->data[D6_OPT_CODE + 1] = code & 0xff; udhcp_find_option tests the code as follows: while (opt_list && opt_list->data[OPT_CODE] < code) ... if (opt_list && opt_list->data[OPT_CODE] == code) So yes, OPT_CODE and D6_OPT_CODE are both 0, but the D6_OPT_CLIENTID = 1 value means that the 1 is in the seconds byte, and udhcp_find_option is only looking at the first byte, So the send_d6_release can never find it the created option. function old new delta udhcp_find_option 28 53 +25 attach_option 276 284 +8 udhcpc6_main 2602 2607 +5 perform_d6_release 262 267 +5 udhcpd_main 1518 1520 +2 udhcpc_main 2542 2544 +2 add_serverid_and_clientid_options 46 48 +2 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 7/0 up/down: 49/0) Total: 49 bytes Signed-off-by: Denys Vlasenko

udhcp: convert log1s() macro to function

2021-06-03T09:12:20+00:00

function old new delta log1s - 15 +15 udhcp_recv_kernel_packet 134 125 -9 d6_recv_kernel_packet 118 109 -9 change_listen_mode 280 271 -9 send_packet 162 141 -21 udhcpc_main 2625 2598 -27 udhcpc6_main 2655 2628 -27 d6_recv_raw_packet 255 216 -39 udhcp_recv_raw_packet 562 484 -78 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/8 up/down: 15/-219) Total: -204 bytes Signed-off-by: Denys Vlasenko

udhcpc: get rid of client_data.fqdn field

2021-06-02T13:51:50+00:00

function old new delta attach_option 253 276 +23 udhcpc_main 2582 2588 +6 udhcpc6_main 2579 2571 -8 add_client_options 175 158 -17 udhcp_insert_new_option 169 138 -31 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/3 up/down: 29/-56) Total: -27 bytes Signed-off-by: Denys Vlasenko

udhcpc: remove deprecated -H/-h HOSTNAME options (9 years), deprecate -V VENDOR

2021-06-02T13:07:46+00:00

function old new delta udhcpc_main 2563 2582 +19 dhcp_option_strings 294 301 +7 dhcp_optflags 80 82 +2 .rodata 103250 103248 -2 udhcpc_longopts 252 241 -11 add_client_options 209 175 -34 alloc_dhcp_option 59 - -59 ------------------------------------------------------------------------------ (add/remove: 0/1 grow/shrink: 3/3 up/down: 28/-106) Total: -78 bytes Signed-off-by: Denys Vlasenko

udhcpc: include client-id option in DECLINEs, even if it's a custom -x 61:HEX option

2021-06-02T12:07:26+00:00

client_data.vendorclass, .hostname and .fqdn probably need the same treatment: just insert them into the list of -x opts, get rid of if (client_data.vendorclass) udhcp_add_binary_option(packet, client_data.vendorclass); if (client_data.hostname) udhcp_add_binary_option(packet, client_data.hostname); if (client_data.fqdn) udhcp_add_binary_option(packet, client_data.fqdn); function old new delta udhcp_insert_new_option - 166 +166 perform_release 171 207 +36 perform_d6_release 227 259 +32 udhcpc6_main 2558 2580 +22 init_d6_packet 103 84 -19 udhcpc_main 2585 2564 -21 attach_option 397 253 -144 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 3/3 up/down: 256/-184) Total: 72 bytes Signed-off-by: Denys Vlasenko

udhcpc: ignore zero-length DHCP options, take 2

2021-03-16T10:42:56+00:00

advance the optionptr by two bytes, not one Signed-off-by: Denys Vlasenko

udhcpc: ignore zero-length DHCP options

2021-03-16T10:40:19+00:00

Discovered that the DHCP server on a TrendNet router (unknown model) provides a zero-length option 12 (Host Name) in the DHCP ACK message. This has the effect of causing udhcpc to drop the rest of the options, including option 51 (IP Address Lease Time), 3 (Router), and 6 (Domain Name Server), most importantly leaving the OpenWrt device with no default gateway. The TrendNet behavior violates RFC 2132, which in Section 3.14 declares that option 12 has a minimum length of 1 octet. It is perhaps not a cosmic coincidence that I found this behavior on Pi Day. This patch allows zero length options without bailing out, by simply skipping them. function old new delta udhcp_scan_options 183 172 -11 Signed-off-by: Russell Senior Signed-off-by: Denys Vlasenko

avoid using strok - eliminates use of hidden global variable

2020-10-06T00:36:47+00:00

function old new delta udhcp_str2optset 616 650 +34 setpriv_main 950 975 +25 switch_root_main 688 706 +18 parse 958 970 +12 getopt_main 622 628 +6 parse_resolvconf 302 306 +4 mpstat_main 1139 1142 +3 static.p 4 - -4 cdcmd 717 702 -15 strtok 148 - -148 ------------------------------------------------------------------------------ (add/remove: 0/3 grow/shrink: 7/1 up/down: 102/-167) Total: -65 bytes Signed-off-by: Denys Vlasenko