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-rw-r--r--sys/net/pfvar.h5
-rw-r--r--sys/netpfil/pf/pf.c112
-rw-r--r--sys/netpfil/pf/pf_ioctl.c13
-rw-r--r--sys/netpfil/pf/pf_norm.c13
4 files changed, 93 insertions, 50 deletions
diff --git a/sys/net/pfvar.h b/sys/net/pfvar.h
index 4a5f2a0..ae5ecb9 100644
--- a/sys/net/pfvar.h
+++ b/sys/net/pfvar.h
@@ -1554,6 +1554,8 @@ extern void pf_print_state(struct pf_state *);
extern void pf_print_flags(u_int8_t);
extern u_int16_t pf_cksum_fixup(u_int16_t, u_int16_t, u_int16_t,
u_int8_t);
+extern u_int16_t pf_proto_cksum_fixup(struct mbuf *, u_int16_t,
+ u_int16_t, u_int16_t, u_int8_t);
VNET_DECLARE(struct ifnet *, sync_ifp);
#define V_sync_ifp VNET(sync_ifp);
@@ -1583,6 +1585,9 @@ u_int32_t pf_new_isn(struct pf_state *);
void *pf_pull_hdr(struct mbuf *, int, void *, int, u_short *, u_short *,
sa_family_t);
void pf_change_a(void *, u_int16_t *, u_int32_t, u_int8_t);
+void pf_change_proto_a(struct mbuf *, void *, u_int16_t *, u_int32_t,
+ u_int8_t);
+void pf_change_tcp_a(struct mbuf *, void *, u_int16_t *, u_int32_t);
void pf_send_deferred_syn(struct pf_state *);
int pf_match_addr(u_int8_t, struct pf_addr *, struct pf_addr *,
struct pf_addr *, sa_family_t);
diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c
index b3268a2..8f3a5ed 100644
--- a/sys/netpfil/pf/pf.c
+++ b/sys/netpfil/pf/pf.c
@@ -203,7 +203,7 @@ static void pf_init_threshold(struct pf_threshold *, u_int32_t,
static void pf_add_threshold(struct pf_threshold *);
static int pf_check_threshold(struct pf_threshold *);
-static void pf_change_ap(struct pf_addr *, u_int16_t *,
+static void pf_change_ap(struct mbuf *, struct pf_addr *, u_int16_t *,
u_int16_t *, u_int16_t *, struct pf_addr *,
u_int16_t, u_int8_t, sa_family_t);
static int pf_modulate_sack(struct mbuf *, int, struct pf_pdesc *,
@@ -1989,6 +1989,22 @@ pf_addr_wrap_neq(struct pf_addr_wrap *aw1, struct pf_addr_wrap *aw2)
}
}
+/**
+ * Checksum updates are a little complicated because the checksum in the TCP/UDP
+ * header isn't always a full checksum. In some cases (i.e. output) it's a
+ * pseudo-header checksum, which is a partial checksum over src/dst IP
+ * addresses, protocol number and length.
+ *
+ * That means we have the following cases:
+ * * Input or forwarding: we don't have TSO, the checksum fields are full
+ * checksums, we need to update the checksum whenever we change anything.
+ * * Output (i.e. the checksum is a pseudo-header checksum):
+ * x The field being updated is src/dst address or affects the length of
+ * the packet. We need to update the pseudo-header checksum (note that this
+ * checksum is not ones' complement).
+ * x Some other field is being modified (e.g. src/dst port numbers): We
+ * don't have to update anything.
+ **/
u_int16_t
pf_cksum_fixup(u_int16_t cksum, u_int16_t old, u_int16_t new, u_int8_t udp)
{
@@ -2004,9 +2020,20 @@ pf_cksum_fixup(u_int16_t cksum, u_int16_t old, u_int16_t new, u_int8_t udp)
return (l);
}
+u_int16_t
+pf_proto_cksum_fixup(struct mbuf *m, u_int16_t cksum, u_int16_t old,
+ u_int16_t new, u_int8_t udp)
+{
+ if (m->m_pkthdr.csum_flags & (CSUM_DELAY_DATA | CSUM_DELAY_DATA_IPV6))
+ return (cksum);
+
+ return (pf_cksum_fixup(cksum, old, new, udp));
+}
+
static void
-pf_change_ap(struct pf_addr *a, u_int16_t *p, u_int16_t *ic, u_int16_t *pc,
- struct pf_addr *an, u_int16_t pn, u_int8_t u, sa_family_t af)
+pf_change_ap(struct mbuf *m, struct pf_addr *a, u_int16_t *p, u_int16_t *ic,
+ u_int16_t *pc, struct pf_addr *an, u_int16_t pn, u_int8_t u,
+ sa_family_t af)
{
struct pf_addr ao;
u_int16_t po = *p;
@@ -2014,6 +2041,9 @@ pf_change_ap(struct pf_addr *a, u_int16_t *p, u_int16_t *ic, u_int16_t *pc,
PF_ACPY(&ao, a, af);
PF_ACPY(a, an, af);
+ if (m->m_pkthdr.csum_flags & (CSUM_DELAY_DATA | CSUM_DELAY_DATA_IPV6))
+ *pc = ~*pc;
+
*p = pn;
switch (af) {
@@ -2023,17 +2053,19 @@ pf_change_ap(struct pf_addr *a, u_int16_t *p, u_int16_t *ic, u_int16_t *pc,
ao.addr16[0], an->addr16[0], 0),
ao.addr16[1], an->addr16[1], 0);
*p = pn;
- *pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(*pc,
+
+ *pc = pf_cksum_fixup(pf_cksum_fixup(*pc,
ao.addr16[0], an->addr16[0], u),
- ao.addr16[1], an->addr16[1], u),
- po, pn, u);
+ ao.addr16[1], an->addr16[1], u);
+
+ *pc = pf_proto_cksum_fixup(m, *pc, po, pn, u);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
*pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
- pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(*pc,
+ pf_cksum_fixup(pf_cksum_fixup(*pc,
ao.addr16[0], an->addr16[0], u),
ao.addr16[1], an->addr16[1], u),
ao.addr16[2], an->addr16[2], u),
@@ -2041,13 +2073,20 @@ pf_change_ap(struct pf_addr *a, u_int16_t *p, u_int16_t *ic, u_int16_t *pc,
ao.addr16[4], an->addr16[4], u),
ao.addr16[5], an->addr16[5], u),
ao.addr16[6], an->addr16[6], u),
- ao.addr16[7], an->addr16[7], u),
- po, pn, u);
+ ao.addr16[7], an->addr16[7], u);
+
+ *pc = pf_proto_cksum_fixup(m, *pc, po, pn, u);
break;
#endif /* INET6 */
}
-}
+ if (m->m_pkthdr.csum_flags & (CSUM_DELAY_DATA |
+ CSUM_DELAY_DATA_IPV6)) {
+ *pc = ~*pc;
+ if (! *pc)
+ *pc = 0xffff;
+ }
+}
/* Changes a u_int32_t. Uses a void * so there are no align restrictions */
void
@@ -2061,6 +2100,19 @@ pf_change_a(void *a, u_int16_t *c, u_int32_t an, u_int8_t u)
ao % 65536, an % 65536, u);
}
+void
+pf_change_proto_a(struct mbuf *m, void *a, u_int16_t *c, u_int32_t an, u_int8_t udp)
+{
+ u_int32_t ao;
+
+ memcpy(&ao, a, sizeof(ao));
+ memcpy(a, &an, sizeof(u_int32_t));
+
+ *c = pf_proto_cksum_fixup(m,
+ pf_proto_cksum_fixup(m, *c, ao / 65536, an / 65536, udp),
+ ao % 65536, an % 65536, udp);
+}
+
#ifdef INET6
static void
pf_change_a6(struct pf_addr *a, u_int16_t *c, struct pf_addr *an, u_int8_t u)
@@ -2206,12 +2258,10 @@ pf_modulate_sack(struct mbuf *m, int off, struct pf_pdesc *pd,
for (i = 2; i + TCPOLEN_SACK <= olen;
i += TCPOLEN_SACK) {
memcpy(&sack, &opt[i], sizeof(sack));
- pf_change_a(&sack.start, &th->th_sum,
- htonl(ntohl(sack.start) -
- dst->seqdiff), 0);
- pf_change_a(&sack.end, &th->th_sum,
- htonl(ntohl(sack.end) -
- dst->seqdiff), 0);
+ pf_change_proto_a(m, &sack.start, &th->th_sum,
+ htonl(ntohl(sack.start) - dst->seqdiff), 0);
+ pf_change_proto_a(m, &sack.end, &th->th_sum,
+ htonl(ntohl(sack.end) - dst->seqdiff), 0);
memcpy(&opt[i], &sack, sizeof(sack));
}
copyback = 1;
@@ -3115,7 +3165,7 @@ pf_test_rule(struct pf_rule **rm, struct pf_state **sm, int direction,
if (PF_ANEQ(saddr, &nk->addr[pd->sidx], af) ||
nk->port[pd->sidx] != sport) {
- pf_change_ap(saddr, &th->th_sport, pd->ip_sum,
+ pf_change_ap(m, saddr, &th->th_sport, pd->ip_sum,
&th->th_sum, &nk->addr[pd->sidx],
nk->port[pd->sidx], 0, af);
pd->sport = &th->th_sport;
@@ -3124,7 +3174,7 @@ pf_test_rule(struct pf_rule **rm, struct pf_state **sm, int direction,
if (PF_ANEQ(daddr, &nk->addr[pd->didx], af) ||
nk->port[pd->didx] != dport) {
- pf_change_ap(daddr, &th->th_dport, pd->ip_sum,
+ pf_change_ap(m, daddr, &th->th_dport, pd->ip_sum,
&th->th_sum, &nk->addr[pd->didx],
nk->port[pd->didx], 0, af);
dport = th->th_dport;
@@ -3138,7 +3188,7 @@ pf_test_rule(struct pf_rule **rm, struct pf_state **sm, int direction,
if (PF_ANEQ(saddr, &nk->addr[pd->sidx], af) ||
nk->port[pd->sidx] != sport) {
- pf_change_ap(saddr, &pd->hdr.udp->uh_sport,
+ pf_change_ap(m, saddr, &pd->hdr.udp->uh_sport,
pd->ip_sum, &pd->hdr.udp->uh_sum,
&nk->addr[pd->sidx],
nk->port[pd->sidx], 1, af);
@@ -3148,7 +3198,7 @@ pf_test_rule(struct pf_rule **rm, struct pf_state **sm, int direction,
if (PF_ANEQ(daddr, &nk->addr[pd->didx], af) ||
nk->port[pd->didx] != dport) {
- pf_change_ap(daddr, &pd->hdr.udp->uh_dport,
+ pf_change_ap(m, daddr, &pd->hdr.udp->uh_dport,
pd->ip_sum, &pd->hdr.udp->uh_sum,
&nk->addr[pd->didx],
nk->port[pd->didx], 1, af);
@@ -3500,7 +3550,7 @@ pf_create_state(struct pf_rule *r, struct pf_rule *nr, struct pf_rule *a,
if ((s->src.seqdiff = pf_tcp_iss(pd) - s->src.seqlo) ==
0)
s->src.seqdiff = 1;
- pf_change_a(&th->th_seq, &th->th_sum,
+ pf_change_proto_a(m, &th->th_seq, &th->th_sum,
htonl(s->src.seqlo + s->src.seqdiff), 0);
*rewrite = 1;
} else
@@ -3824,9 +3874,9 @@ pf_tcp_track_full(struct pf_state_peer *src, struct pf_state_peer *dst,
while ((src->seqdiff = arc4random() - seq) == 0)
;
ack = ntohl(th->th_ack) - dst->seqdiff;
- pf_change_a(&th->th_seq, &th->th_sum, htonl(seq +
+ pf_change_proto_a(m, &th->th_seq, &th->th_sum, htonl(seq +
src->seqdiff), 0);
- pf_change_a(&th->th_ack, &th->th_sum, htonl(ack), 0);
+ pf_change_proto_a(m, &th->th_ack, &th->th_sum, htonl(ack), 0);
*copyback = 1;
} else {
ack = ntohl(th->th_ack);
@@ -3876,9 +3926,9 @@ pf_tcp_track_full(struct pf_state_peer *src, struct pf_state_peer *dst,
ack = ntohl(th->th_ack) - dst->seqdiff;
if (src->seqdiff) {
/* Modulate sequence numbers */
- pf_change_a(&th->th_seq, &th->th_sum, htonl(seq +
+ pf_change_proto_a(m, &th->th_seq, &th->th_sum, htonl(seq +
src->seqdiff), 0);
- pf_change_a(&th->th_ack, &th->th_sum, htonl(ack), 0);
+ pf_change_proto_a(m, &th->th_ack, &th->th_sum, htonl(ack), 0);
*copyback = 1;
}
end = seq + pd->p_len;
@@ -4332,14 +4382,14 @@ pf_test_state_tcp(struct pf_state **state, int direction, struct pfi_kif *kif,
if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], pd->af) ||
nk->port[pd->sidx] != th->th_sport)
- pf_change_ap(pd->src, &th->th_sport, pd->ip_sum,
- &th->th_sum, &nk->addr[pd->sidx],
+ pf_change_ap(m, pd->src, &th->th_sport,
+ pd->ip_sum, &th->th_sum, &nk->addr[pd->sidx],
nk->port[pd->sidx], 0, pd->af);
if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], pd->af) ||
nk->port[pd->didx] != th->th_dport)
- pf_change_ap(pd->dst, &th->th_dport, pd->ip_sum,
- &th->th_sum, &nk->addr[pd->didx],
+ pf_change_ap(m, pd->dst, &th->th_dport,
+ pd->ip_sum, &th->th_sum, &nk->addr[pd->didx],
nk->port[pd->didx], 0, pd->af);
copyback = 1;
}
@@ -4403,13 +4453,13 @@ pf_test_state_udp(struct pf_state **state, int direction, struct pfi_kif *kif,
if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], pd->af) ||
nk->port[pd->sidx] != uh->uh_sport)
- pf_change_ap(pd->src, &uh->uh_sport, pd->ip_sum,
+ pf_change_ap(m, pd->src, &uh->uh_sport, pd->ip_sum,
&uh->uh_sum, &nk->addr[pd->sidx],
nk->port[pd->sidx], 1, pd->af);
if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], pd->af) ||
nk->port[pd->didx] != uh->uh_dport)
- pf_change_ap(pd->dst, &uh->uh_dport, pd->ip_sum,
+ pf_change_ap(m, pd->dst, &uh->uh_dport, pd->ip_sum,
&uh->uh_sum, &nk->addr[pd->didx],
nk->port[pd->didx], 1, pd->af);
m_copyback(m, off, sizeof(*uh), (caddr_t)uh);
diff --git a/sys/netpfil/pf/pf_ioctl.c b/sys/netpfil/pf/pf_ioctl.c
index a3528f0..d91c851 100644
--- a/sys/netpfil/pf/pf_ioctl.c
+++ b/sys/netpfil/pf/pf_ioctl.c
@@ -3560,12 +3560,6 @@ pf_check_out(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
{
int chk;
- /* We need a proper CSUM befor we start (s. OpenBSD ip_output) */
- if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
- in_delayed_cksum(*m);
- (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
- }
-
chk = pf_test(PF_OUT, ifp, m, inp);
if (chk && *m) {
m_freem(*m);
@@ -3604,13 +3598,6 @@ pf_check6_out(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
{
int chk;
- /* We need a proper CSUM before we start (s. OpenBSD ip_output) */
- if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
- in6_delayed_cksum(*m,
- (*m)->m_pkthdr.len - sizeof(struct ip6_hdr),
- sizeof(struct ip6_hdr));
- (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
- }
CURVNET_SET(ifp->if_vnet);
chk = pf_test6(PF_OUT, ifp, m, inp);
CURVNET_RESTORE();
diff --git a/sys/netpfil/pf/pf_norm.c b/sys/netpfil/pf/pf_norm.c
index d56ad3c..4f9a499 100644
--- a/sys/netpfil/pf/pf_norm.c
+++ b/sys/netpfil/pf/pf_norm.c
@@ -1680,13 +1680,14 @@ pf_normalize_tcp(int dir, struct pfi_kif *kif, struct mbuf *m, int ipoff,
th->th_x2 = 0;
nv = *(u_int16_t *)(&th->th_ack + 1);
- th->th_sum = pf_cksum_fixup(th->th_sum, ov, nv, 0);
+ th->th_sum = pf_proto_cksum_fixup(m, th->th_sum, ov, nv, 0);
rewrite = 1;
}
/* Remove urgent pointer, if TH_URG is not set */
if (!(flags & TH_URG) && th->th_urp) {
- th->th_sum = pf_cksum_fixup(th->th_sum, th->th_urp, 0, 0);
+ th->th_sum = pf_proto_cksum_fixup(m, th->th_sum, th->th_urp,
+ 0, 0);
th->th_urp = 0;
rewrite = 1;
}
@@ -1887,7 +1888,7 @@ pf_normalize_tcp_stateful(struct mbuf *m, int off, struct pf_pdesc *pd,
(src->scrub->pfss_flags &
PFSS_TIMESTAMP)) {
tsval = ntohl(tsval);
- pf_change_a(&opt[2],
+ pf_change_proto_a(m, &opt[2],
&th->th_sum,
htonl(tsval +
src->scrub->pfss_ts_mod),
@@ -1903,7 +1904,7 @@ pf_normalize_tcp_stateful(struct mbuf *m, int off, struct pf_pdesc *pd,
PFSS_TIMESTAMP)) {
tsecr = ntohl(tsecr)
- dst->scrub->pfss_ts_mod;
- pf_change_a(&opt[6],
+ pf_change_proto_a(m, &opt[6],
&th->th_sum, htonl(tsecr),
0);
copyback = 1;
@@ -2230,8 +2231,8 @@ pf_normalize_tcpopt(struct pf_rule *r, struct mbuf *m, struct tcphdr *th,
case TCPOPT_MAXSEG:
mss = (u_int16_t *)(optp + 2);
if ((ntohs(*mss)) > r->max_mss) {
- th->th_sum = pf_cksum_fixup(th->th_sum,
- *mss, htons(r->max_mss), 0);
+ th->th_sum = pf_proto_cksum_fixup(m,
+ th->th_sum, *mss, htons(r->max_mss), 0);
*mss = htons(r->max_mss);
rewrite = 1;
}
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