On Sat, May 06, 2023 at 09:33:05PM +0200, Alexander Bluhm wrote:
> On Sat, May 06, 2023 at 11:11:25AM +0000, Klemens Nanni wrote:
> > pf_osfp.c contains all the locking for these three ioctls, this removes
> > the net lock from it.
> >
> > All data is protected by the pf lock, new asserts verify that.
> >
> > Beside the pf ioctl handler, pf_match_rule()'s call to pf_osfp_match()
> > is the only hook into it.
> >
> > tcpbump still compiles pf_osfp.c without object change.
> >
> > Feedback? OK?
>
> Could you document that pf_osfp_list and fp_next is protected by
> pf lock?
Picked [p] for pf_lock so as to not collide with pfvar_priv.h's comment
about "Protection/owernership of pf_state members".
> There is nothing in pf_osfp_fingerprint() that needs pf lock directly.
> The critical access is the SLIST_FOREACH in pf_osfp_find(). Place
> the PF_ASSERT_LOCKED() there.
Misplaced, thanks.
> Why is pf_osfp_list passed to pf_osfp_find() and pf_osfp_find_exact()?
> Can we remove the parameter and just use pf_osfp_list?
Wanted to clean this up in a separate diff, but we might as well do
everything in one go.
Index: pf_osfp.c
===================================================================
RCS file: /cvs/src/sys/net/pf_osfp.c,v
retrieving revision 1.45
diff -u -p -r1.45 pf_osfp.c
--- pf_osfp.c 15 Dec 2020 15:23:48 -0000 1.45
+++ pf_osfp.c 6 May 2023 20:52:07 -0000
@@ -60,10 +60,9 @@ typedef struct pool pool_t;
#define pool_put(pool, item) free(item)
#define pool_init(pool, size, a, ao, f, m, p) (*(pool)) = (size)
-#define NET_LOCK()
-#define NET_UNLOCK()
#define PF_LOCK()
#define PF_UNLOCK()
+#define PF_ASSERT_LOCKED()
#ifdef PFDEBUG
#include <sys/stdarg.h> /* for DPFPRINTF() */
@@ -71,16 +70,21 @@ typedef struct pool pool_t;
#endif /* _KERNEL */
-SLIST_HEAD(pf_osfp_list, pf_os_fingerprint) pf_osfp_list;
-pool_t pf_osfp_entry_pl;
-pool_t pf_osfp_pl;
-
-struct pf_os_fingerprint *pf_osfp_find(struct pf_osfp_list *,
- struct pf_os_fingerprint *, u_int8_t);
-struct pf_os_fingerprint *pf_osfp_find_exact(struct pf_osfp_list *,
- struct pf_os_fingerprint *);
-void pf_osfp_insert(struct pf_osfp_list *,
- struct pf_os_fingerprint *);
+/*
+ * Protection/ownership:
+ * I immutable after pf_osfp_initialize()
+ * p pf_lock
+ */
+
+SLIST_HEAD(pf_osfp_list, pf_os_fingerprint) pf_osfp_list =
+ SLIST_HEAD_INITIALIZER(pf_osfp_list); /* [p] */
+pool_t pf_osfp_entry_pl; /* [I] */
+pool_t pf_osfp_pl; /* [I] */
+
+struct pf_os_fingerprint *pf_osfp_find(struct pf_os_fingerprint *,
+ u_int8_t);
+struct pf_os_fingerprint *pf_osfp_find_exact(struct pf_os_fingerprint *);
+void pf_osfp_insert(struct pf_os_fingerprint *);
#ifdef _KERNEL
@@ -257,8 +261,7 @@ pf_osfp_fingerprint_hdr(const struct ip
(fp.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "",
fp.fp_wscale);
- if ((fpresult = pf_osfp_find(&pf_osfp_list, &fp,
- PF_OSFP_MAXTTL_OFFSET)))
+ if ((fpresult = pf_osfp_find(&fp, PF_OSFP_MAXTTL_OFFSET)))
return (&fpresult->fp_oses);
return (NULL);
}
@@ -302,7 +305,6 @@ pf_osfp_initialize(void)
IPL_NONE, PR_WAITOK, "pfosfpen", NULL);
pool_init(&pf_osfp_pl, sizeof(struct pf_os_fingerprint), 0,
IPL_NONE, PR_WAITOK, "pfosfp", NULL);
- SLIST_INIT(&pf_osfp_list);
}
/* Flush the fingerprint list */
@@ -312,7 +314,6 @@ pf_osfp_flush(void)
struct pf_os_fingerprint *fp;
struct pf_osfp_entry *entry;
- NET_LOCK();
PF_LOCK();
while ((fp = SLIST_FIRST(&pf_osfp_list))) {
SLIST_REMOVE_HEAD(&pf_osfp_list, fp_next);
@@ -323,7 +324,6 @@ pf_osfp_flush(void)
pool_put(&pf_osfp_pl, fp);
}
PF_UNLOCK();
- NET_UNLOCK();
}
@@ -379,14 +379,12 @@ pf_osfp_add(struct pf_osfp_ioctl *fpioc)
return (ENOMEM);
}
- NET_LOCK();
PF_LOCK();
- if ((fp = pf_osfp_find_exact(&pf_osfp_list, &fpadd))) {
+ if ((fp = pf_osfp_find_exact(&fpadd))) {
struct pf_osfp_entry *tentry;
SLIST_FOREACH(tentry, &fp->fp_oses, fp_entry) {
if (PF_OSFP_ENTRY_EQ(tentry, &fpioc->fp_os)) {
- NET_UNLOCK();
PF_UNLOCK();
pool_put(&pf_osfp_entry_pl, entry);
pool_put(&pf_osfp_pl, fp_prealloc);
@@ -405,7 +403,7 @@ pf_osfp_add(struct pf_osfp_ioctl *fpioc)
fp->fp_wscale = fpioc->fp_wscale;
fp->fp_ttl = fpioc->fp_ttl;
SLIST_INIT(&fp->fp_oses);
- pf_osfp_insert(&pf_osfp_list, fp);
+ pf_osfp_insert(fp);
}
memcpy(entry, &fpioc->fp_os, sizeof(*entry));
@@ -416,7 +414,6 @@ pf_osfp_add(struct pf_osfp_ioctl *fpioc)
SLIST_INSERT_HEAD(&fp->fp_oses, entry, fp_entry);
PF_UNLOCK();
- NET_UNLOCK();
#ifdef PFDEBUG
if ((fp = pf_osfp_validate()))
@@ -433,11 +430,12 @@ pf_osfp_add(struct pf_osfp_ioctl *fpioc)
/* Find a fingerprint in the list */
struct pf_os_fingerprint *
-pf_osfp_find(struct pf_osfp_list *list, struct pf_os_fingerprint *find,
- u_int8_t ttldiff)
+pf_osfp_find(struct pf_os_fingerprint *find, u_int8_t ttldiff)
{
struct pf_os_fingerprint *f;
+ PF_ASSERT_LOCKED();
+
#define MATCH_INT(_MOD, _DC, _field) \
if ((f->fp_flags & _DC) == 0) { \
if ((f->fp_flags & _MOD) == 0) { \
@@ -449,7 +447,7 @@ pf_osfp_find(struct pf_osfp_list *list,
} \
}
- SLIST_FOREACH(f, list, fp_next) {
+ SLIST_FOREACH(f, &pf_osfp_list, fp_next) {
if (f->fp_tcpopts != find->fp_tcpopts ||
f->fp_optcnt != find->fp_optcnt ||
f->fp_ttl < find->fp_ttl ||
@@ -507,11 +505,13 @@ pf_osfp_find(struct pf_osfp_list *list,
/* Find an exact fingerprint in the list */
struct pf_os_fingerprint *
-pf_osfp_find_exact(struct pf_osfp_list *list, struct pf_os_fingerprint *find)
+pf_osfp_find_exact(struct pf_os_fingerprint *find)
{
struct pf_os_fingerprint *f;
- SLIST_FOREACH(f, list, fp_next) {
+ PF_ASSERT_LOCKED();
+
+ SLIST_FOREACH(f, &pf_osfp_list, fp_next) {
if (f->fp_tcpopts == find->fp_tcpopts &&
f->fp_wsize == find->fp_wsize &&
f->fp_psize == find->fp_psize &&
@@ -528,18 +528,20 @@ pf_osfp_find_exact(struct pf_osfp_list *
/* Insert a fingerprint into the list */
void
-pf_osfp_insert(struct pf_osfp_list *list, struct pf_os_fingerprint *ins)
+pf_osfp_insert(struct pf_os_fingerprint *ins)
{
struct pf_os_fingerprint *f, *prev = NULL;
+ PF_ASSERT_LOCKED();
+
/* XXX need to go semi tree based. can key on tcp options */
- SLIST_FOREACH(f, list, fp_next)
+ SLIST_FOREACH(f, &pf_osfp_list, fp_next)
prev = f;
if (prev)
SLIST_INSERT_AFTER(prev, ins, fp_next);
else
- SLIST_INSERT_HEAD(list, ins, fp_next);
+ SLIST_INSERT_HEAD(&pf_osfp_list, ins, fp_next);
}
/* Fill a fingerprint by its number (from an ioctl) */
@@ -551,9 +553,7 @@ pf_osfp_get(struct pf_osfp_ioctl *fpioc)
int num = fpioc->fp_getnum;
int i = 0;
-
memset(fpioc, 0, sizeof(*fpioc));
- NET_LOCK();
PF_LOCK();
SLIST_FOREACH(fp, &pf_osfp_list, fp_next) {
SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) {
@@ -568,13 +568,11 @@ pf_osfp_get(struct pf_osfp_ioctl *fpioc)
memcpy(&fpioc->fp_os, entry,
sizeof(fpioc->fp_os));
PF_UNLOCK();
- NET_UNLOCK();
return (0);
}
}
}
PF_UNLOCK();
- NET_UNLOCK();
return (EBUSY);
}
@@ -586,6 +584,8 @@ pf_osfp_validate(void)
{
struct pf_os_fingerprint *f, *f2, find;
+ PF_ASSERT_LOCKED();
+
SLIST_FOREACH(f, &pf_osfp_list, fp_next) {
memcpy(&find, f, sizeof(find));
@@ -598,7 +598,7 @@ pf_osfp_validate(void)
find.fp_wsize *= (find.fp_mss + 40);
else if (f->fp_flags & PF_OSFP_WSIZE_MOD)
find.fp_wsize *= 2;
- if (f != (f2 = pf_osfp_find(&pf_osfp_list, &find, 0))) {
+ if (f != (f2 = pf_osfp_find(&find, 0))) {
if (f2)
DPFPRINTF(LOG_NOTICE,
"Found \"%s %s %s\" instead of "
