[git commit] udhcpc6: fix udhcp_find_option to actually find DHCP6 options
Denys Vlasenko
vda.linux at googlemail.com
Sun Dec 12 16:13:54 UTC 2021
commit: https://git.busybox.net/busybox/commit/?id=e67b80f4739c4075b51b0a575701b73928fe0bf1
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master
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 <vda.linux at googlemail.com>
---
networking/udhcp/common.c | 29 ++++++++++++++++++++++-------
networking/udhcp/common.h | 6 +++++-
networking/udhcp/d6_dhcpc.c | 5 +++--
networking/udhcp/dhcpc.c | 6 +++---
networking/udhcp/dhcpd.c | 2 +-
5 files changed, 34 insertions(+), 14 deletions(-)
diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
index 31e525cb0..8e9b93655 100644
--- a/networking/udhcp/common.c
+++ b/networking/udhcp/common.c
@@ -404,14 +404,29 @@ void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code,
#endif
/* Find option 'code' in opt_list */
-struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
+struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code, bool dhcpv6)
{
- while (opt_list && opt_list->data[OPT_CODE] < code)
- opt_list = opt_list->next;
+ IF_NOT_UDHCPC6(bool dhcpv6 = 0;)
+ uint8_t cur_code;
- if (opt_list && opt_list->data[OPT_CODE] == code)
- return opt_list;
- return NULL;
+ for (;;) {
+ if (!opt_list)
+ return opt_list; /* NULL */
+ if (!dhcpv6) {
+ cur_code = opt_list->data[OPT_CODE];
+ } else {
+//FIXME: add support for code > 0xff
+ if (opt_list->data[D6_OPT_CODE] != 0)
+ return NULL;
+ cur_code = opt_list->data[D6_OPT_CODE + 1];
+ }
+ if (cur_code >= code) {
+ if (cur_code == code)
+ return opt_list;
+ return NULL;
+ }
+ opt_list = opt_list->next;
+ }
}
/* Parse string to IP in network order */
@@ -499,7 +514,7 @@ static NOINLINE void attach_option(
}
#endif
- existing = udhcp_find_option(*opt_list, optflag->code);
+ existing = udhcp_find_option(*opt_list, optflag->code, dhcpv6);
if (!existing) {
/* make a new option */
uint8_t *p = udhcp_insert_new_option(opt_list, optflag->code, length, dhcpv6);
diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
index e374771cb..5882238e3 100644
--- a/networking/udhcp/common.h
+++ b/networking/udhcp/common.h
@@ -245,7 +245,11 @@ void udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t
char *dname_dec(const uint8_t *cstr, int clen, const char *pre) FAST_FUNC;
uint8_t *dname_enc(/*const uint8_t *cstr, int clen,*/ const char *src, int *retlen) FAST_FUNC;
#endif
-struct option_set *udhcp_find_option(struct option_set *opt_list, uint8_t code) FAST_FUNC;
+#if !ENABLE_UDHCPC6
+#define udhcp_find_option(opt_list, code, dhcpv6) \
+ udhcp_find_option(opt_list, code)
+#endif
+struct option_set *udhcp_find_option(struct option_set *opt_list, uint8_t code, bool dhcpv6) FAST_FUNC;
// RFC 2131 Table 5: Fields and options used by DHCP clients
//
diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c
index 8d11a7539..9d2a8f5d3 100644
--- a/networking/udhcp/d6_dhcpc.c
+++ b/networking/udhcp/d6_dhcpc.c
@@ -888,7 +888,8 @@ int send_d6_release(struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
if (client6_data.ia_pd)
opt_ptr = mempcpy(opt_ptr, client6_data.ia_pd, client6_data.ia_pd->len + 2+2);
/* Client-id */
- ci = udhcp_find_option(client_data.options, D6_OPT_CLIENTID);
+///vda
+ ci = udhcp_find_option(client_data.options, D6_OPT_CLIENTID, /*dhcpv6:*/ 1);
if (ci)
opt_ptr = mempcpy(opt_ptr, ci->data, D6_OPT_DATA + 2+2 + 6);
@@ -1272,7 +1273,7 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
}
clientid_mac_ptr = NULL;
- if (!udhcp_find_option(client_data.options, D6_OPT_CLIENTID)) {
+ if (!udhcp_find_option(client_data.options, D6_OPT_CLIENTID, /*dhcpv6:*/ 1)) {
/* not set, set the default client ID */
clientid_mac_ptr = udhcp_insert_new_option(
&client_data.options, D6_OPT_CLIENTID,
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 331f13a8c..c757fb37c 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -658,7 +658,7 @@ static void add_client_options(struct dhcp_packet *packet)
// This will be needed if we remove -V VENDOR_STR in favor of
// -x vendor:VENDOR_STR
- //if (!udhcp_find_option(packet.options, DHCP_VENDOR))
+ //if (!udhcp_find_option(packet.options, DHCP_VENDOR, /*dhcpv6:*/ 0))
// /* not set, set the default vendor ID */
// ...add (DHCP_VENDOR, "udhcp "BB_VER) opt...
}
@@ -676,7 +676,7 @@ static void add_serverid_and_clientid_options(struct dhcp_packet *packet, uint32
* If the client used a 'client identifier' when it obtained the lease,
* it MUST use the same 'client identifier' in the DHCPRELEASE message.
*/
- ci = udhcp_find_option(client_data.options, DHCP_CLIENT_ID);
+ ci = udhcp_find_option(client_data.options, DHCP_CLIENT_ID, /*dhcpv6:*/ 0);
if (ci)
udhcp_add_binary_option(packet, ci->data);
}
@@ -1328,7 +1328,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
}
clientid_mac_ptr = NULL;
- if (!(opt & OPT_C) && !udhcp_find_option(client_data.options, DHCP_CLIENT_ID)) {
+ if (!(opt & OPT_C) && !udhcp_find_option(client_data.options, DHCP_CLIENT_ID, /*dhcpv6:*/ 0)) {
/* not suppressed and not set, create default client ID */
clientid_mac_ptr = udhcp_insert_new_option(
&client_data.options, DHCP_CLIENT_ID,
diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index 0f5edb75c..66750e2e6 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -935,7 +935,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
bb_simple_info_msg("started, v"BB_VER);
- option = udhcp_find_option(server_data.options, DHCP_LEASE_TIME);
+ option = udhcp_find_option(server_data.options, DHCP_LEASE_TIME, /*dhcpv6:*/ 0);
server_data.max_lease_sec = DEFAULT_LEASE_TIME;
if (option) {
move_from_unaligned32(server_data.max_lease_sec, option->data + OPT_DATA);
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