pfioctl: drop net lock from DIOCOSFP{FLUSH,ADD,GET}

[Klemens Nanni]

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?

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   3 May 2023 21:55:21 -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() */
@@ -96,6 +95,8 @@ pf_osfp_fingerprint(struct pf_pdesc *pd)
        struct ip6_hdr  *ip6 = NULL;
        char             hdr[60];
 
+       PF_ASSERT_LOCKED();
+
        if (pd->proto != IPPROTO_TCP)
                return (NULL);
 
@@ -312,7 +313,6 @@ 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 +323,6 @@ pf_osfp_flush(void)
                pool_put(&pf_osfp_pl, fp);
        }
        PF_UNLOCK();
-       NET_UNLOCK();
 }
 
 
@@ -379,14 +378,12 @@ pf_osfp_add(struct pf_osfp_ioctl *fpioc)
                return (ENOMEM);
        }
 
-       NET_LOCK();
        PF_LOCK();
        if ((fp = pf_osfp_find_exact(&pf_osfp_list, &fpadd))) {
                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);
@@ -416,7 +413,6 @@ 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()))
@@ -553,7 +549,6 @@ pf_osfp_get(struct pf_osfp_ioctl *fpioc)
 
 
        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 +563,11 @@ 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);
 }
@@ -585,6 +578,8 @@ struct pf_os_fingerprint *
 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));