Module Name: src
Committed By: riastradh
Date: Mon Aug 31 20:23:56 UTC 2020
Modified Files:
src/sys/net: if_wg.c
Log Message:
wg: Use thmap(9) for peer and session lookup.
Make sure we also don't trip over our own shoelaces by choosing the
same session index twice.
To generate a diff of this commit:
cvs rdiff -u -r1.36 -r1.37 src/sys/net/if_wg.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/net/if_wg.c
diff -u src/sys/net/if_wg.c:1.36 src/sys/net/if_wg.c:1.37
--- src/sys/net/if_wg.c:1.36 Mon Aug 31 20:21:30 2020
+++ src/sys/net/if_wg.c Mon Aug 31 20:23:56 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: if_wg.c,v 1.36 2020/08/31 20:21:30 riastradh Exp $ */
+/* $NetBSD: if_wg.c,v 1.37 2020/08/31 20:23:56 riastradh Exp $ */
/*
* Copyright (C) Ryota Ozaki <ozaki.ry...@gmail.com>
@@ -41,7 +41,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.36 2020/08/31 20:21:30 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.37 2020/08/31 20:23:56 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_inet.h"
@@ -77,6 +77,7 @@ __KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/systm.h>
+#include <sys/thmap.h>
#include <sys/time.h>
#include <sys/timespec.h>
@@ -603,6 +604,9 @@ struct wg_softc {
int wg_npeers;
struct pslist_head wg_peers;
+ struct thmap *wg_peers_bypubkey;
+ struct thmap *wg_peers_byname;
+ struct thmap *wg_sessions_byindex;
uint16_t wg_listen_port;
struct wg_worker *wg_worker;
@@ -1159,6 +1163,52 @@ wg_unlock_session(struct wg_peer *wgp, s
}
#endif
+static uint32_t
+wg_assign_sender_index(struct wg_softc *wg, struct wg_session *wgs)
+{
+ struct wg_peer *wgp = wgs->wgs_peer;
+ struct wg_session *wgs0;
+ uint32_t index;
+ void *garbage;
+
+ mutex_enter(wgs->wgs_lock);
+
+ /* Release the current index, if there is one. */
+ while ((index = wgs->wgs_sender_index) != 0) {
+ /* Remove the session by index. */
+ thmap_del(wg->wg_sessions_byindex, &index, sizeof index);
+ wgs->wgs_sender_index = 0;
+ mutex_exit(wgs->wgs_lock);
+
+ /* Wait for all thmap_gets to complete, and GC. */
+ garbage = thmap_stage_gc(wg->wg_sessions_byindex);
+ mutex_enter(wgs->wgs_peer->wgp_lock);
+ pserialize_perform(wgp->wgp_psz);
+ mutex_exit(wgs->wgs_peer->wgp_lock);
+ thmap_gc(wg->wg_sessions_byindex, garbage);
+
+ mutex_enter(wgs->wgs_lock);
+ }
+
+restart:
+ /* Pick a uniform random nonzero index. */
+ while (__predict_false((index = cprng_strong32()) == 0))
+ continue;
+
+ /* Try to take it. */
+ wgs->wgs_sender_index = index;
+ wgs0 = thmap_put(wg->wg_sessions_byindex,
+ &wgs->wgs_sender_index, sizeof wgs->wgs_sender_index, wgs);
+
+ /* If someone else beat us, start over. */
+ if (__predict_false(wgs0 != wgs))
+ goto restart;
+
+ mutex_exit(wgs->wgs_lock);
+
+ return index;
+}
+
/*
* Handshake patterns
*
@@ -1192,7 +1242,7 @@ wg_fill_msg_init(struct wg_softc *wg, st
uint8_t privkey[WG_EPHEMERAL_KEY_LEN];
wgmi->wgmi_type = WG_MSG_TYPE_INIT;
- wgmi->wgmi_sender = cprng_strong32();
+ wgmi->wgmi_sender = wg_assign_sender_index(wg, wgs);
/* [W] 5.4.2: First Message: Initiator to Responder */
@@ -1267,7 +1317,6 @@ wg_fill_msg_init(struct wg_softc *wg, st
memcpy(wgs->wgs_ephemeral_key_priv, privkey, sizeof(privkey));
memcpy(wgs->wgs_handshake_hash, hash, sizeof(hash));
memcpy(wgs->wgs_chaining_key, ckey, sizeof(ckey));
- wgs->wgs_sender_index = wgmi->wgmi_sender;
WG_DLOG("%s: sender=%x\n", __func__, wgs->wgs_sender_index);
}
@@ -1609,7 +1658,7 @@ wg_fill_msg_resp(struct wg_softc *wg, st
memcpy(ckey, wgs->wgs_chaining_key, sizeof(ckey));
wgmr->wgmr_type = WG_MSG_TYPE_RESP;
- wgmr->wgmr_sender = cprng_strong32();
+ wgmr->wgmr_sender = wg_assign_sender_index(wg, wgs);
wgmr->wgmr_receiver = wgmi->wgmi_sender;
/* [W] 5.4.3 Second Message: Responder to Initiator */
@@ -1680,7 +1729,6 @@ wg_fill_msg_resp(struct wg_softc *wg, st
memcpy(wgs->wgs_chaining_key, ckey, sizeof(ckey));
memcpy(wgs->wgs_ephemeral_key_pub, pubkey, sizeof(pubkey));
memcpy(wgs->wgs_ephemeral_key_priv, privkey, sizeof(privkey));
- wgs->wgs_sender_index = wgmr->wgmr_sender;
wgs->wgs_receiver_index = wgmi->wgmi_sender;
WG_DLOG("sender=%x\n", wgs->wgs_sender_index);
WG_DLOG("receiver=%x\n", wgs->wgs_receiver_index);
@@ -1906,12 +1954,7 @@ wg_lookup_peer_by_pubkey(struct wg_softc
struct wg_peer *wgp;
int s = pserialize_read_enter();
- /* XXX O(n) */
- WG_PEER_READER_FOREACH(wgp, wg) {
- if (consttime_memequal(wgp->wgp_pubkey, pubkey,
- sizeof(wgp->wgp_pubkey)))
- break;
- }
+ wgp = thmap_get(wg->wg_peers_bypubkey, pubkey, WG_STATIC_KEY_LEN);
if (wgp != NULL)
wg_get_peer(wgp, psref);
pserialize_read_exit(s);
@@ -2087,24 +2130,10 @@ static struct wg_session *
wg_lookup_session_by_index(struct wg_softc *wg, const uint32_t index,
struct psref *psref)
{
- struct wg_peer *wgp;
struct wg_session *wgs;
int s = pserialize_read_enter();
- /* XXX O(n) */
- WG_PEER_READER_FOREACH(wgp, wg) {
- wgs = wgp->wgp_session_stable;
- WG_DLOG("index=%x wgs_sender_index=%x\n",
- index, wgs->wgs_sender_index);
- if (wgs->wgs_sender_index == index)
- break;
- wgs = wgp->wgp_session_unstable;
- WG_DLOG("index=%x wgs_sender_index=%x\n",
- index, wgs->wgs_sender_index);
- if (wgs->wgs_sender_index == index)
- break;
- wgs = NULL;
- }
+ wgs = thmap_get(wg->wg_sessions_byindex, &index, sizeof index);
if (wgs != NULL)
psref_acquire(psref, &wgs->wgs_psref, wg_psref_class);
pserialize_read_exit(s);
@@ -3262,7 +3291,10 @@ wg_destroy_peer(struct wg_peer *wgp)
{
struct wg_session *wgs;
struct wg_softc *wg = wgp->wgp_sc;
+ uint32_t index;
+ void *garbage;
+ /* Prevent new packets from this peer on any source address. */
rw_enter(wg->wg_rwlock, RW_WRITER);
for (int i = 0; i < wgp->wgp_n_allowedips; i++) {
struct wg_allowedip *wga = &wgp->wgp_allowedips[i];
@@ -3281,11 +3313,29 @@ wg_destroy_peer(struct wg_peer *wgp)
}
rw_exit(wg->wg_rwlock);
+ /* Halt all packet processing and timeouts. */
softint_disestablish(wgp->wgp_si);
callout_halt(&wgp->wgp_rekey_timer, NULL);
callout_halt(&wgp->wgp_handshake_timeout_timer, NULL);
callout_halt(&wgp->wgp_session_dtor_timer, NULL);
+ /* Remove the sessions by index. */
+ if ((index = wgp->wgp_session_stable->wgs_sender_index) != 0) {
+ thmap_del(wg->wg_sessions_byindex, &index, sizeof index);
+ wgp->wgp_session_stable->wgs_sender_index = 0;
+ }
+ if ((index = wgp->wgp_session_unstable->wgs_sender_index) != 0) {
+ thmap_del(wg->wg_sessions_byindex, &index, sizeof index);
+ wgp->wgp_session_unstable->wgs_sender_index = 0;
+ }
+
+ /* Wait for all thmap_gets to complete, and GC. */
+ garbage = thmap_stage_gc(wg->wg_sessions_byindex);
+ mutex_enter(wgp->wgp_lock);
+ pserialize_perform(wgp->wgp_psz);
+ mutex_exit(wgp->wgp_lock);
+ thmap_gc(wg->wg_sessions_byindex, garbage);
+
wgs = wgp->wgp_session_unstable;
psref_target_destroy(&wgs->wgs_psref, wg_psref_class);
mutex_obj_free(wgs->wgs_lock);
@@ -3295,6 +3345,7 @@ wg_destroy_peer(struct wg_peer *wgp)
mutex_destroy(&wgs->wgs_send_counter_lock);
#endif
kmem_free(wgs, sizeof(*wgs));
+
wgs = wgp->wgp_session_stable;
psref_target_destroy(&wgs->wgs_psref, wg_psref_class);
mutex_obj_free(wgs->wgs_lock);
@@ -3320,11 +3371,23 @@ wg_destroy_peer(struct wg_peer *wgp)
static void
wg_destroy_all_peers(struct wg_softc *wg)
{
- struct wg_peer *wgp;
+ struct wg_peer *wgp, *wgp0 __diagused;
+ void *garbage_byname, *garbage_bypubkey;
restart:
+ garbage_byname = garbage_bypubkey = NULL;
mutex_enter(wg->wg_lock);
WG_PEER_WRITER_FOREACH(wgp, wg) {
+ if (wgp->wgp_name[0]) {
+ wgp0 = thmap_del(wg->wg_peers_byname, wgp->wgp_name,
+ strlen(wgp->wgp_name));
+ KASSERT(wgp0 == wgp);
+ garbage_byname = thmap_stage_gc(wg->wg_peers_byname);
+ }
+ wgp0 = thmap_del(wg->wg_peers_bypubkey, wgp->wgp_pubkey,
+ sizeof(wgp->wgp_pubkey));
+ KASSERT(wgp0 == wgp);
+ garbage_bypubkey = thmap_stage_gc(wg->wg_peers_bypubkey);
WG_PEER_WRITER_REMOVE(wgp);
wg->wg_npeers--;
mutex_enter(wgp->wgp_lock);
@@ -3342,6 +3405,8 @@ restart:
psref_target_destroy(&wgp->wgp_psref, wg_psref_class);
wg_destroy_peer(wgp);
+ thmap_gc(wg->wg_peers_byname, garbage_byname);
+ thmap_gc(wg->wg_peers_bypubkey, garbage_bypubkey);
goto restart;
}
@@ -3349,14 +3414,17 @@ restart:
static int
wg_destroy_peer_name(struct wg_softc *wg, const char *name)
{
- struct wg_peer *wgp;
+ struct wg_peer *wgp, *wgp0 __diagused;
+ void *garbage_byname, *garbage_bypubkey;
mutex_enter(wg->wg_lock);
- WG_PEER_WRITER_FOREACH(wgp, wg) {
- if (strcmp(wgp->wgp_name, name) == 0)
- break;
- }
+ wgp = thmap_del(wg->wg_peers_byname, name, strlen(name));
if (wgp != NULL) {
+ wgp0 = thmap_del(wg->wg_peers_bypubkey, wgp->wgp_pubkey,
+ sizeof(wgp->wgp_pubkey));
+ KASSERT(wgp0 == wgp);
+ garbage_byname = thmap_stage_gc(wg->wg_peers_byname);
+ garbage_bypubkey = thmap_stage_gc(wg->wg_peers_bypubkey);
WG_PEER_WRITER_REMOVE(wgp);
wg->wg_npeers--;
mutex_enter(wgp->wgp_lock);
@@ -3373,6 +3441,8 @@ wg_destroy_peer_name(struct wg_softc *wg
psref_target_destroy(&wgp->wgp_psref, wg_psref_class);
wg_destroy_peer(wgp);
+ thmap_gc(wg->wg_peers_byname, garbage_byname);
+ thmap_gc(wg->wg_peers_bypubkey, garbage_bypubkey);
return 0;
}
@@ -3432,6 +3502,9 @@ wg_clone_create(struct if_clone *ifc, in
#endif
PSLIST_INIT(&wg->wg_peers);
+ wg->wg_peers_bypubkey = thmap_create(0, NULL, THMAP_NOCOPY);
+ wg->wg_peers_byname = thmap_create(0, NULL, THMAP_NOCOPY);
+ wg->wg_sessions_byindex = thmap_create(0, NULL, THMAP_NOCOPY);
wg->wg_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
wg->wg_rwlock = rw_obj_alloc();
wg->wg_ops = &wg_ops_rumpkernel;
@@ -3445,6 +3518,9 @@ wg_clone_create(struct if_clone *ifc, in
free(wg->wg_rtable_ipv6, M_RTABLE);
PSLIST_DESTROY(&wg->wg_peers);
mutex_obj_free(wg->wg_lock);
+ thmap_destroy(wg->wg_sessions_byindex);
+ thmap_destroy(wg->wg_peers_byname);
+ thmap_destroy(wg->wg_peers_bypubkey);
kmem_free(wg, sizeof(struct wg_softc));
return error;
}
@@ -3482,6 +3558,9 @@ wg_clone_destroy(struct ifnet *ifp)
free(wg->wg_rtable_ipv6, M_RTABLE);
PSLIST_DESTROY(&wg->wg_peers);
+ thmap_destroy(wg->wg_sessions_byindex);
+ thmap_destroy(wg->wg_peers_byname);
+ thmap_destroy(wg->wg_peers_bypubkey);
mutex_obj_free(wg->wg_lock);
rw_obj_free(wg->wg_rwlock);
@@ -4076,7 +4155,7 @@ wg_ioctl_add_peer(struct wg_softc *wg, s
int error;
prop_dictionary_t prop_dict;
char *buf = NULL;
- struct wg_peer *wgp = NULL;
+ struct wg_peer *wgp = NULL, *wgp0 __diagused;
error = wg_alloc_prop_buf(&buf, ifd);
if (error != 0)
@@ -4091,6 +4170,24 @@ wg_ioctl_add_peer(struct wg_softc *wg, s
goto out;
mutex_enter(wg->wg_lock);
+ if (thmap_get(wg->wg_peers_bypubkey, wgp->wgp_pubkey,
+ sizeof(wgp->wgp_pubkey)) != NULL ||
+ (wgp->wgp_name[0] &&
+ thmap_get(wg->wg_peers_byname, wgp->wgp_name,
+ strlen(wgp->wgp_name)) != NULL)) {
+ mutex_exit(wg->wg_lock);
+ wg_destroy_peer(wgp);
+ error = EEXIST;
+ goto out;
+ }
+ wgp0 = thmap_put(wg->wg_peers_bypubkey, wgp->wgp_pubkey,
+ sizeof(wgp->wgp_pubkey), wgp);
+ KASSERT(wgp0 == wgp);
+ if (wgp->wgp_name[0]) {
+ wgp0 = thmap_put(wg->wg_peers_byname, wgp->wgp_name,
+ strlen(wgp->wgp_name), wgp);
+ KASSERT(wgp0 == wgp);
+ }
WG_PEER_WRITER_INSERT_HEAD(wgp, wg);
wg->wg_npeers++;
mutex_exit(wg->wg_lock);
