MFC: r311817

In dummynet(4), random chunks of memory are casted to struct dn_*,
potentially leading to fatal unaligned accesses on architectures with
strict alignment requirements. This change fixes dummynet(4) as far
as accesses to 64-bit members of struct dn_* are concerned, tripping
up on sparc64 with accesses to 32-bit members happening to be correctly
aligned there. In other words, this only fixes the tip of the iceberg;
larger parts of dummynet(4) still need to be rewritten in order to
properly work on all of !x86.
In principle, considering the amount of code in dummynet(4) that needs
this erroneous pattern corrected, an acceptable workaround would be to
declare all struct dn_* packed, forcing compilers to do byte-accesses
as a side-effect. However, given that the structs in question aren't
laid out well either, this would break ABI/KBI.
While at it, replace all existing bcopy(9) calls with memcpy(9) for
performance reasons, as there is no need to check for overlap in these
cases.

PR:		189219
(cherry picked from commit 1477d32c8175c9dd8b564ec8b3057c8b7be41bac)

1 files changed, 115 insertions, 65 deletions

diff --git a/sys/netpfil/ipfw/ip_dummynet.c b/sys/netpfil/ipfw/ip_dummynet.c
index 20ce6d1..9fdcc13 100644
--- a/sys/netpfil/ipfw/ip_dummynet.c
+++ b/sys/netpfil/ipfw/ip_dummynet.c
@@ -931,29 +931,35 @@ delete_schk(int i)
 static int
 copy_obj(char **start, char *end, void *_o, const char *msg, int i)
 {
-	struct dn_id *o = _o;
+	struct dn_id o;
+	union {
+		struct dn_link l;
+		struct dn_schk s;
+	} dn;
 	int have = end - *start;
 
-	if (have < o->len || o->len == 0 || o->type == 0) {
+	memcpy(&o, _o, sizeof(o));
+	if (have < o.len || o.len == 0 || o.type == 0) {
 		D("(WARN) type %d %s %d have %d need %d",
-			o->type, msg, i, have, o->len);
+		    o.type, msg, i, have, o.len);
 		return 1;
 	}
-	ND("type %d %s %d len %d", o->type, msg, i, o->len);
-	bcopy(_o, *start, o->len);
-	if (o->type == DN_LINK) {
+	ND("type %d %s %d len %d", o.type, msg, i, o.len);
+	if (o.type == DN_LINK) {
+		memcpy(&dn.l, _o, sizeof(dn.l));
 		/* Adjust burst parameter for link */
-		struct dn_link *l = (struct dn_link *)*start;
-		l->burst =  div64(l->burst, 8 * hz);
-		l->delay = l->delay * 1000 / hz;
-	} else if (o->type == DN_SCH) {
-		/* Set id->id to the number of instances */
-		struct dn_schk *s = _o;
-		struct dn_id *id = (struct dn_id *)(*start);
-		id->id = (s->sch.flags & DN_HAVE_MASK) ?
-			dn_ht_entries(s->siht) : (s->siht ? 1 : 0);
-	}
-	*start += o->len;
+		dn.l.burst = div64(dn.l.burst, 8 * hz);
+		dn.l.delay = dn.l.delay * 1000 / hz;
+		memcpy(*start, &dn.l, sizeof(dn.l));
+	} else if (o.type == DN_SCH) {
+		/* Set dn.s.sch.oid.id to the number of instances */
+		memcpy(&dn.s, _o, sizeof(dn.s));
+		dn.s.sch.oid.id = (dn.s.sch.flags & DN_HAVE_MASK) ?
+		    dn_ht_entries(dn.s.siht) : (dn.s.siht ? 1 : 0);
+		memcpy(*start, &dn.s, sizeof(dn.s));
+	} else
+		memcpy(*start, _o, o.len);
+	*start += o.len;
 	return 0;
 }
 
@@ -974,7 +980,7 @@ copy_obj_q(char **start, char *end, void *_o, const char *msg, int i)
 		return 1;
 	}
 	ND("type %d %s %d len %d", o->type, msg, i, len);
-	bcopy(_o, *start, len);
+	memcpy(*start, _o, len);
 	((struct dn_id*)(*start))->len = len;
 	*start += len;
 	return 0;
@@ -1022,7 +1028,7 @@ copy_profile(struct copy_args *a, struct dn_profile *p)
 		D("error have %d need %d", have, profile_len);
 		return 1;
 	}
-	bcopy(p, *a->start, profile_len);
+	memcpy(*a->start, p, profile_len);
 	((struct dn_id *)(*a->start))->len = profile_len;
 	*a->start += profile_len;
 	return 0;
@@ -1584,6 +1590,9 @@ config_fs(struct dn_fs *nfs, struct dn_id *arg, int locked)
 {
 	int i;
 	struct dn_fsk *fs;
+#ifdef NEW_AQM
+	struct dn_extra_parms *ep;
+#endif
 
 	if (nfs->oid.len != sizeof(*nfs)) {
 		D("invalid flowset len %d", nfs->oid.len);
@@ -1592,6 +1601,15 @@ config_fs(struct dn_fs *nfs, struct dn_id *arg, int locked)
 	i = nfs->fs_nr;
 	if (i <= 0 || i >= 3*DN_MAX_ID)
 		return NULL;
+#ifdef NEW_AQM
+	ep = NULL;
+	if (arg != NULL) {
+		ep = malloc(sizeof(*ep), M_TEMP, locked ? M_NOWAIT : M_WAITOK);
+		if (ep == NULL)
+			return (NULL);
+		memcpy(ep, arg, sizeof(*ep));
+	}
+#endif
 	ND("flowset %d", i);
 	/* XXX other sanity checks */
         if (nfs->flags & DN_QSIZE_BYTES) {
@@ -1630,12 +1648,15 @@ config_fs(struct dn_fs *nfs, struct dn_id *arg, int locked)
 	    if (bcmp(&fs->fs, nfs, sizeof(*nfs)) == 0) {
 		ND("flowset %d unchanged", i);
 #ifdef NEW_AQM
-		/* reconfigure AQM as the parameters can be changed.
-		 * we consider the flowsetis  busy if it has scheduler instance(s) 
-		*/ 
-		s = locate_scheduler(nfs->sched_nr);
-		config_aqm(fs, (struct dn_extra_parms *) arg, 
-			s != NULL && s->siht != NULL);
+		if (ep != NULL) {
+			/*
+			 * Reconfigure AQM as the parameters can be changed.
+			 * We consider the flowset as busy if it has scheduler
+			 * instance(s).
+			 */ 
+			s = locate_scheduler(nfs->sched_nr);
+			config_aqm(fs, ep, s != NULL && s->siht != NULL);
+		}
 #endif
 		break; /* no change, nothing to do */
 	    }
@@ -1657,13 +1678,19 @@ config_fs(struct dn_fs *nfs, struct dn_id *arg, int locked)
 	    fs->fs = *nfs; /* copy configuration */
 #ifdef NEW_AQM
 			fs->aqmfp = NULL;
-			config_aqm(fs, (struct dn_extra_parms *) arg, s != NULL && s->siht != NULL);
+			if (ep != NULL)
+				config_aqm(fs, ep, s != NULL &&
+				    s->siht != NULL);
 #endif
 	    if (s != NULL)
 		fsk_attach(fs, s);
 	} while (0);
 	if (!locked)
 		DN_BH_WUNLOCK();
+#ifdef NEW_AQM
+	if (ep != NULL)
+		free(ep, M_TEMP);
+#endif
 	return fs;
 }
 
@@ -1773,7 +1800,7 @@ again: /* run twice, for wfq and fifo */
 				D("cannot allocate profile");
 				goto error; //XXX
 			}
-			bcopy(pf, s->profile, sizeof(*pf));
+			memcpy(s->profile, pf, sizeof(*pf));
 		}
 	}
 	p.link_nr = 0;
@@ -1795,7 +1822,7 @@ again: /* run twice, for wfq and fifo */
 				pf = malloc(sizeof(*pf),
 				    M_DUMMYNET, M_NOWAIT | M_ZERO);
 			if (pf)	/* XXX should issue a warning otherwise */
-				bcopy(s->profile, pf, sizeof(*pf));
+				memcpy(pf, s->profile, sizeof(*pf));
 		}
 		/* remove from the hash */
 		dn_ht_find(dn_cfg.schedhash, i, DNHT_REMOVE, NULL);
@@ -1917,7 +1944,7 @@ config_profile(struct dn_profile *pf, struct dn_id *arg)
 		olen = s->profile->oid.len;
 		if (olen < pf->oid.len)
 			olen = pf->oid.len;
-		bcopy(pf, s->profile, pf->oid.len);
+		memcpy(s->profile, pf, pf->oid.len);
 		s->profile->oid.len = olen;
 	}
 	DN_BH_WUNLOCK();
@@ -1953,30 +1980,35 @@ dummynet_flush(void)
 int
 do_config(void *p, int l)
 {
-	struct dn_id *next, *o;
-	int err = 0, err2 = 0;
-	struct dn_id *arg = NULL;
-	uintptr_t *a;
-
-	o = p;
-	if (o->id != DN_API_VERSION) {
-		D("invalid api version got %d need %d",
-			o->id, DN_API_VERSION);
+	struct dn_id o;
+	union {
+		struct dn_profile profile;
+		struct dn_fs fs;
+		struct dn_link link;
+		struct dn_sch sched;
+	} *dn;
+	struct dn_id *arg;
+	uintptr_t a;
+	int err, err2, off;
+
+	memcpy(&o, p, sizeof(o));
+	if (o.id != DN_API_VERSION) {
+		D("invalid api version got %d need %d", o.id, DN_API_VERSION);
 		return EINVAL;
 	}
-	for (; l >= sizeof(*o); o = next) {
-		struct dn_id *prev = arg;
-		if (o->len < sizeof(*o) || l < o->len) {
-			D("bad len o->len %d len %d", o->len, l);
+	arg = NULL;
+	dn = NULL;
+	for (off = 0; l >= sizeof(o); memcpy(&o, (char *)p + off, sizeof(o))) {
+		if (o.len < sizeof(o) || l < o.len) {
+			D("bad len o.len %d len %d", o.len, l);
 			err = EINVAL;
 			break;
 		}
-		l -= o->len;
-		next = (struct dn_id *)((char *)o + o->len);
+		l -= o.len;
 		err = 0;
-		switch (o->type) {
+		switch (o.type) {
 		default:
-			D("cmd %d not implemented", o->type);
+			D("cmd %d not implemented", o.type);
 			break;
 
 #ifdef EMULATE_SYSCTL
@@ -1994,31 +2026,30 @@ do_config(void *p, int l)
 
 		case DN_CMD_DELETE:
 			/* the argument is in the first uintptr_t after o */
-			a = (uintptr_t *)(o+1);
-			if (o->len < sizeof(*o) + sizeof(*a)) {
+			if (o.len < sizeof(o) + sizeof(a)) {
 				err = EINVAL;
 				break;
 			}
-			switch (o->subtype) {
+			memcpy(&a, (char *)p + off + sizeof(o), sizeof(a));
+			switch (o.subtype) {
 			case DN_LINK:
 				/* delete base and derived schedulers */
 				DN_BH_WLOCK();
-				err = delete_schk(*a);
-				err2 = delete_schk(*a + DN_MAX_ID);
+				err = delete_schk(a);
+				err2 = delete_schk(a + DN_MAX_ID);
 				DN_BH_WUNLOCK();
 				if (!err)
 					err = err2;
 				break;
 
 			default:
-				D("invalid delete type %d",
-					o->subtype);
+				D("invalid delete type %d", o.subtype);
 				err = EINVAL;
 				break;
 
 			case DN_FS:
-				err = (*a <1 || *a >= DN_MAX_ID) ?
-					EINVAL : delete_fs(*a, 0) ;
+				err = (a < 1 || a >= DN_MAX_ID) ?
+				    EINVAL : delete_fs(a, 0) ;
 				break;
 			}
 			break;
@@ -2028,28 +2059,47 @@ do_config(void *p, int l)
 			dummynet_flush();
 			DN_BH_WUNLOCK();
 			break;
-		case DN_TEXT:	/* store argument the next block */
-			prev = NULL;
-			arg = o;
+		case DN_TEXT:	/* store argument of next block */
+			if (arg != NULL)
+				free(arg, M_TEMP);
+			arg = malloc(o.len, M_TEMP, M_WAITOK);
+			memcpy(arg, (char *)p + off, o.len);
 			break;
 		case DN_LINK:
-			err = config_link((struct dn_link *)o, arg);
+			if (dn == NULL)
+				dn = malloc(sizeof(*dn), M_TEMP, M_WAITOK);
+			memcpy(&dn->link, (char *)p + off, sizeof(dn->link));
+			err = config_link(&dn->link, arg);
 			break;
 		case DN_PROFILE:
-			err = config_profile((struct dn_profile *)o, arg);
+			if (dn == NULL)
+				dn = malloc(sizeof(*dn), M_TEMP, M_WAITOK);
+			memcpy(&dn->profile, (char *)p + off,
+			    sizeof(dn->profile));
+			err = config_profile(&dn->profile, arg);
 			break;
 		case DN_SCH:
-			err = config_sched((struct dn_sch *)o, arg);
+			if (dn == NULL)
+				dn = malloc(sizeof(*dn), M_TEMP, M_WAITOK);
+			memcpy(&dn->sched, (char *)p + off,
+			    sizeof(dn->sched));
+			err = config_sched(&dn->sched, arg);
 			break;
 		case DN_FS:
-			err = (NULL==config_fs((struct dn_fs *)o, arg, 0));
+			if (dn == NULL)
+				dn = malloc(sizeof(*dn), M_TEMP, M_WAITOK);
+			memcpy(&dn->fs, (char *)p + off, sizeof(dn->fs));
+			err = (NULL == config_fs(&dn->fs, arg, 0));
 			break;
 		}
-		if (prev)
-			arg = NULL;
 		if (err != 0)
 			break;
+		off += o.len;
 	}
+	if (arg != NULL)
+		free(arg, M_TEMP);
+	if (dn != NULL)
+		free(dn, M_TEMP);
 	return err;
 }
 
@@ -2261,7 +2311,7 @@ dummynet_get(struct sockopt *sopt, void **compat)
 	a.type = cmd->subtype;
 
 	if (compat == NULL) {
-		bcopy(cmd, start, sizeof(*cmd));
+		memcpy(start, cmd, sizeof(*cmd));
 		((struct dn_id*)(start))->len = sizeof(struct dn_id);
 		buf = start + sizeof(*cmd);
 	} else