accel-ppp.git/accel-pppd/ppp, branch sstp-alloc-invariant

Merge pull request #330 from nuclearcat/ipv6cp-term-fix

2026-07-18T21:55:50+00:00

ppp: don't terminate session on IPV6CP TermReq unless IPv6 is required

Merge pull request #334 from nuclearcat/ppp-unit-fd-close-race

2026-07-18T21:55:36+00:00

ppp: close unit fd only after session cleanup finishes

ipv6cp: fix byte order of default interface-id values

2026-07-12T20:11:39+00:00

The default fixed interface-ids conf_intf_id_val=1 and conf_peer_intf_id_val=2 were plain host-order integers, while every consumer (build_ip6_addr(), ifcfg.c, nd.c, dhcpv6.c) treats intf_id as an opaque 8-byte value in network byte order and copies it verbatim into the low 64 bits of the IPv6 address. parse_intfid() also produces network byte order, so only the built-in defaults were affected. On little-endian hosts this produced fe80::100:0:0:0 (and ::200:0:0:0 for the peer) instead of the intended fe80::1 / ::2 whenever ipv6-intf-id / ipv6-peer-intf-id were not set in the config. Store the defaults with htobe64() so the resulting addresses are ::1 and ::2 regardless of host endianness. The assignment is done in init() because htobe64() is not a constant expression on all libcs. Note: on little-endian deployments this changes the server link-local address from fe80::100:0:0:0 to fe80::1 when ipv6-intf-id is unset.

ppp: close unit fd only after session cleanup finishes

2026-07-08T10:21:14+00:00

destablish_ppp() closed the ppp unit fd (via triton_md_unregister_handler(..., 1)) before calling ap_session_finished(). Closing the fd releases the ppp unit index, so the kernel can assign the same unit (and thus the same pppX ifname) to a new session while the old session's cleanup is still running. pppd_compat performs its cleanup from the EV_SES_FINISHED handler: it runs the ip-down script (blocking the context until the script exits) and then deletes radattr.pppX. If the unit index is reused in that window, the ip-down script is executed with an IFNAME that now belongs to a different, active session, and remove_radattr() deletes the radattr file of that new session. External accounting/shaper scripts that read radattr.pppX then fail for a live session. Fix this by unregistering the unit fd handler without closing the fd and closing it only after ap_session_finished() returns, unless the fd was handed to the unit cache. This keeps the unit index reserved until session cleanup has finished, so the ifname cannot be reused early. The unit-cache path is not affected (the cached fd already keeps the unit reserved); the race only hits configurations with unit-cache disabled. Only PPP sessions (PPPoE/PPTP/L2TP/SSTP) go through this path; IPoE is unaffected. Note the unit index is now held slightly longer during teardown (while ip-down runs) - this is intentional. Signed-off-by: Denys Fedoryshchenko

ppp: don't terminate session on IPV6CP TermReq unless IPv6 is required

2026-07-06T21:51:44+00:00

Some broken CPE routers (e.g. Phicomm KE2M, older Linksys) negotiate IPV6CP successfully but then fail to configure IPv6 locally and send IPV6CP TermReq while intending to keep using the session for IPv4. accel-ppp currently terminates the whole session on any IPV6CP TermReq, which violates the RFC 1661 section 3.7 implementation note: "the fact that one NCP has Closed is not sufficient reason to cause the termination of the PPP link, even if that NCP was the only NCP currently in the Opened state." Terminate the session only when ipv6=require. Otherwise mark the layer passive so session bring-up can proceed if IPV6CP never started. The TermReq handler change alone is not enough for these routers: they send TermReq *after* IPV6CP has opened, so ipv6cp->started is already set and ipv6cp_layer_finished() (reached via TermAck or the restart timer once the FSM winds down through Stopping->Stopped) would still kill the session through its started branch. Apply the same policy there: only terminate if ipv6=require, otherwise log and keep the session running IPv4-only. In require mode the TermReq path still records TERM_USER_REQUEST as before (and sets ses->terminating, so layer_finished doesn't override the cause); TERM_USER_ERROR in layer_finished now only covers genuine negotiation failures. Based on the fix proposed by Marek Michalkiewicz and reworked by Alarig Le Lay. Closes: https://github.com/accel-ppp/accel-ppp/issues/57 Supersedes: https://github.com/accel-ppp/accel-ppp/pull/298 Signed-off-by: Denys Fedoryshchenko

ppp: Defend from possible ppp init failure

2026-02-06T15:34:54+00:00

ppp init might fail due malloc failure, missing or invalid runtime state, failure to setup resources (sockers, timers, handler registration), etc. This is quite unlikely now, but some floating(hard to catch) bugs says better to be safe than sorry. Signed-off-by: Denys Fedoryshchenko

fix(ppp): Uninitialized struct fields

2026-02-06T15:34:54+00:00

Initialized the ifreq in destablish_ppp to avoid the uninitialized-struct warning before use. Signed-off-by: Denys Fedoryshchenko

ppp: classic TOCTOU, as uc_size not guarded by mutex

2026-02-06T15:34:54+00:00

It was a micro-optimization to skip taking the mutex when uc_size was 0. But because uc_size isnt atomic and wasnt read under the lock, it created a TOCTOU window. Signed-off-by: Denys Fedoryshchenko

ppp: guard LCP logging field reads

2026-02-06T15:34:54+00:00

Signed-off-by: Denys Fedoryshchenko

crypto: Removed internal tomcat crypto.

2025-12-10T17:16:42+00:00

Signed-off-by: Andrii Melnychenko