git: b590f17a11aa - main - pf: support masking mac addresses
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Date: Wed, 02 Mar 2022 16:01:07 UTC
The branch main has been updated by kp:
URL: https://cgit.FreeBSD.org/src/commit/?id=b590f17a11aacaeb0a70d075df04d40c6b7eb947
commit b590f17a11aacaeb0a70d075df04d40c6b7eb947
Author: Kristof Provost <kp@FreeBSD.org>
AuthorDate: 2022-01-20 17:31:45 +0000
Commit: Kristof Provost <kp@FreeBSD.org>
CommitDate: 2022-03-02 16:00:08 +0000
pf: support masking mac addresses
When filtering Ethernet packets allow rules to specify a mac address
with a mask. This indicates which bits of the specified address are
significant. This allows users to do things like filter based on device
manufacturer.
Sponsored by: Rubicon Communications, LLC ("Netgate")
---
lib/libpfctl/libpfctl.c | 5 +++
lib/libpfctl/libpfctl.h | 1 +
sbin/pfctl/parse.y | 97 +++++++++++++++++++++++++++++++++++++++++------
sbin/pfctl/pfctl_parser.c | 33 +++++++++++++++-
sbin/pfctl/pfctl_parser.h | 1 +
share/man/man5/pf.conf.5 | 2 +
sys/net/pfvar.h | 1 +
sys/netpfil/pf/pf.c | 12 ++++--
sys/netpfil/pf/pf_nv.c | 4 ++
9 files changed, 140 insertions(+), 16 deletions(-)
diff --git a/lib/libpfctl/libpfctl.c b/lib/libpfctl/libpfctl.c
index 90733d421572..07699d66deaa 100644
--- a/lib/libpfctl/libpfctl.c
+++ b/lib/libpfctl/libpfctl.c
@@ -557,6 +557,10 @@ pfctl_nveth_addr_to_eth_addr(const nvlist_t *nvl, struct pfctl_eth_addr *addr)
assert(len == sizeof(addr->addr));
memcpy(addr->addr, data, sizeof(addr->addr));
+ data = nvlist_get_binary(nvl, "mask", &len);
+ assert(len == sizeof(addr->mask));
+ memcpy(addr->mask, data, sizeof(addr->mask));
+
addr->neg = nvlist_get_bool(nvl, "neg");
/* To make checks for 'is this address set?' easier. */
@@ -574,6 +578,7 @@ pfctl_eth_addr_to_nveth_addr(const struct pfctl_eth_addr *addr)
nvlist_add_bool(nvl, "neg", addr->neg);
nvlist_add_binary(nvl, "addr", &addr->addr, ETHER_ADDR_LEN);
+ nvlist_add_binary(nvl, "mask", &addr->mask, ETHER_ADDR_LEN);
return (nvl);
}
diff --git a/lib/libpfctl/libpfctl.h b/lib/libpfctl/libpfctl.h
index 256fa49c4f25..4f8f55945d4b 100644
--- a/lib/libpfctl/libpfctl.h
+++ b/lib/libpfctl/libpfctl.h
@@ -73,6 +73,7 @@ struct pfctl_eth_rules_info {
struct pfctl_eth_addr {
uint8_t addr[ETHER_ADDR_LEN];
+ uint8_t mask[ETHER_ADDR_LEN];
bool neg;
bool isset;
};
diff --git a/sbin/pfctl/parse.y b/sbin/pfctl/parse.y
index 5f10c4ab2e17..346ec9d9a587 100644
--- a/sbin/pfctl/parse.y
+++ b/sbin/pfctl/parse.y
@@ -377,6 +377,9 @@ int invalid_redirect(struct node_host *, sa_family_t);
u_int16_t parseicmpspec(char *, sa_family_t);
int kw_casecmp(const void *, const void *);
int map_tos(char *string, int *);
+struct node_mac* node_mac_from_string(const char *);
+struct node_mac* node_mac_from_string_masklen(const char *, int);
+struct node_mac* node_mac_from_string_mask(const char *, const char *);
static TAILQ_HEAD(loadanchorshead, loadanchors)
loadanchorshead = TAILQ_HEAD_INITIALIZER(loadanchorshead);
@@ -3277,22 +3280,25 @@ etherto : /* empty */ {
}
;
-mac : string {
- $$ = calloc(1, sizeof(struct node_mac));
+mac : string '/' NUMBER {
+ $$ = node_mac_from_string_masklen($1, $3);
+ free($1);
if ($$ == NULL)
- err(1, "mac: calloc");
-
- if (sscanf($1, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
- &$$->mac[0], &$$->mac[1], &$$->mac[2], &$$->mac[3], &$$->mac[4],
- &$$->mac[5]) != 6) {
- free($$);
- free($1);
- yyerror("invalid MAC address");
YYERROR;
+ }
+ | string {
+ if (strchr($1, '&')) {
+ /* mac&mask */
+ char *mac = strtok($1, "&");
+ char *mask = strtok(NULL, "&");
+ $$ = node_mac_from_string_mask(mac, mask);
+ } else {
+ $$ = node_mac_from_string($1);
}
free($1);
- $$->next = NULL;
- $$->tail = $$;
+ if ($$ == NULL)
+ YYERROR;
+
}
xmac : not mac {
struct node_mac *n;
@@ -5741,8 +5747,10 @@ expand_eth_rule(struct pfctl_eth_rule *r,
r->ifnot = interface->not;
r->proto = proto->proto;
bcopy(src->mac, r->src.addr, ETHER_ADDR_LEN);
+ bcopy(src->mask, r->src.mask, ETHER_ADDR_LEN);
r->src.neg = src->neg;
bcopy(dst->mac, r->dst.addr, ETHER_ADDR_LEN);
+ bcopy(dst->mask, r->dst.mask, ETHER_ADDR_LEN);
r->dst.neg = dst->neg;
r->nr = pf->eastack[pf->asd]->match++;
@@ -6899,3 +6907,68 @@ rt_tableid_max(void)
return (RT_TABLEID_MAX);
#endif
}
+
+struct node_mac*
+node_mac_from_string(const char *str)
+{
+ struct node_mac *m;
+
+ m = calloc(1, sizeof(struct node_mac));
+ if (m == NULL)
+ err(1, "mac: calloc");
+
+ if (sscanf(str, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
+ &m->mac[0], &m->mac[1], &m->mac[2], &m->mac[3], &m->mac[4],
+ &m->mac[5]) != 6) {
+ free(m);
+ yyerror("invalid MAC address");
+ return (NULL);
+ }
+
+ memset(m->mask, 0xff, ETHER_ADDR_LEN);
+ m->next = NULL;
+ m->tail = m;
+
+ return (m);
+}
+
+struct node_mac*
+node_mac_from_string_masklen(const char *str, int masklen)
+{
+ struct node_mac *m;
+
+ if (masklen < 0 || masklen > (ETHER_ADDR_LEN * 8)) {
+ yyerror("invalid MAC mask length");
+ return (NULL);
+ }
+
+ m = node_mac_from_string(str);
+ if (m == NULL)
+ return (NULL);
+
+ memset(m->mask, 0, ETHER_ADDR_LEN);
+ for (int i = 0; i < masklen; i++)
+ m->mask[i / 8] |= 1 << (i % 8);
+
+ return (m);
+}
+
+struct node_mac*
+node_mac_from_string_mask(const char *str, const char *mask)
+{
+ struct node_mac *m;
+
+ m = node_mac_from_string(str);
+ if (m == NULL)
+ return (NULL);
+
+ if (sscanf(mask, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
+ &m->mask[0], &m->mask[1], &m->mask[2], &m->mask[3], &m->mask[4],
+ &m->mask[5]) != 6) {
+ free(m);
+ yyerror("invalid MAC mask");
+ return (NULL);
+ }
+
+ return (m);
+}
diff --git a/sbin/pfctl/pfctl_parser.c b/sbin/pfctl/pfctl_parser.c
index 0db0ad355cf7..1637d7358d0d 100644
--- a/sbin/pfctl/pfctl_parser.c
+++ b/sbin/pfctl/pfctl_parser.c
@@ -694,7 +694,9 @@ print_src_node(struct pf_src_node *sn, int opts)
static void
print_eth_addr(const struct pfctl_eth_addr *a)
{
- int i;
+ int i, masklen = ETHER_ADDR_LEN * 8;
+ bool seen_unset = false;
+
for (i = 0; i < ETHER_ADDR_LEN; i++) {
if (a->addr[i] != 0)
break;
@@ -707,6 +709,35 @@ print_eth_addr(const struct pfctl_eth_addr *a)
printf("%s%02x:%02x:%02x:%02x:%02x:%02x", a->neg ? "! " : "",
a->addr[0], a->addr[1], a->addr[2], a->addr[3], a->addr[4],
a->addr[5]);
+
+ for (i = 0; i < (ETHER_ADDR_LEN * 8); i++) {
+ bool isset = a->mask[i / 8] & (1 << i % 8);
+
+ if (! seen_unset) {
+ if (isset)
+ continue;
+ seen_unset = true;
+ masklen = i;
+ } else {
+ /* Not actually a continuous mask, so print the whole
+ * thing. */
+ if (isset)
+ break;
+ continue;
+ }
+ }
+
+ if (masklen == (ETHER_ADDR_LEN * 8))
+ return;
+
+ if (i == (ETHER_ADDR_LEN * 8)) {
+ printf("/%d", masklen);
+ return;
+ }
+
+ printf("&%02x:%02x:%02x:%02x:%02x:%02x",
+ a->mask[0], a->mask[1], a->mask[2], a->mask[3], a->mask[4],
+ a->mask[5]);
}
void
diff --git a/sbin/pfctl/pfctl_parser.h b/sbin/pfctl/pfctl_parser.h
index e60132d15855..60bbae7a3fcd 100644
--- a/sbin/pfctl/pfctl_parser.h
+++ b/sbin/pfctl/pfctl_parser.h
@@ -138,6 +138,7 @@ struct node_host {
struct node_mac {
u_int8_t mac[ETHER_ADDR_LEN];
+ u_int8_t mask[ETHER_ADDR_LEN];
bool neg;
struct node_mac *next;
struct node_mac *tail;
diff --git a/share/man/man5/pf.conf.5 b/share/man/man5/pf.conf.5
index 1bed985901f2..13ff88586d8e 100644
--- a/share/man/man5/pf.conf.5
+++ b/share/man/man5/pf.conf.5
@@ -3178,6 +3178,8 @@ protospec = "proto" ( proto-name | proto-number |
proto-list = ( proto-name | proto-number ) [ [ "," ] proto-list ]
etherhosts = "from" macaddress "to" macaddress
+macaddress = mac | mac "/" masklen | mac "&" mask
+
hosts = "all" |
"from" ( "any" | "no-route" | "urpf-failed" | "self" | host |
"{" host-list "}" ) [ port ] [ os ]
diff --git a/sys/net/pfvar.h b/sys/net/pfvar.h
index a2265e7cc1c5..252b3adbe958 100644
--- a/sys/net/pfvar.h
+++ b/sys/net/pfvar.h
@@ -579,6 +579,7 @@ union pf_keth_rule_ptr {
struct pf_keth_rule_addr {
uint8_t addr[ETHER_ADDR_LEN];
+ uint8_t mask[ETHER_ADDR_LEN];
bool neg;
uint8_t isset;
};
diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c
index bd82c2a9904e..fb0abc8cd035 100644
--- a/sys/netpfil/pf/pf.c
+++ b/sys/netpfil/pf/pf.c
@@ -3809,14 +3809,20 @@ pf_tcp_iss(struct pf_pdesc *pd)
static bool
pf_match_eth_addr(const uint8_t *a, const struct pf_keth_rule_addr *r)
{
+ bool match = true;
+
/* Always matches if not set */
if (! r->isset)
return (!r->neg);
- if (memcmp(a, r->addr, ETHER_ADDR_LEN) == 0)
- return (!r->neg);
+ for (int i = 0; i < ETHER_ADDR_LEN; i++) {
+ if ((a[i] & r->mask[i]) != (r->addr[i] & r->mask[i])) {
+ match = false;
+ break;
+ }
+ }
- return (r->neg);
+ return (match ^ r->neg);
}
static int
diff --git a/sys/netpfil/pf/pf_nv.c b/sys/netpfil/pf/pf_nv.c
index 5fc222ff3b79..42434dabf565 100644
--- a/sys/netpfil/pf/pf_nv.c
+++ b/sys/netpfil/pf/pf_nv.c
@@ -1013,6 +1013,9 @@ pf_nveth_rule_addr_to_keth_rule_addr(const nvlist_t *nvl,
PFNV_CHK(pf_nvbinary(nvl, "addr", &krule->addr, sizeof(krule->addr)));
PFNV_CHK(pf_nvbool(nvl, "neg", &krule->neg));
+ if (nvlist_exists_binary(nvl, "mask"))
+ PFNV_CHK(pf_nvbinary(nvl, "mask", &krule->mask,
+ sizeof(krule->mask)));
/* To make checks for 'is this address set?' easier. */
if (memcmp(krule->addr, EMPTY_MAC, ETHER_ADDR_LEN) != 0)
@@ -1032,6 +1035,7 @@ pf_keth_rule_addr_to_nveth_rule_addr(const struct pf_keth_rule_addr *krule)
return (NULL);
nvlist_add_binary(nvl, "addr", &krule->addr, sizeof(krule->addr));
+ nvlist_add_binary(nvl, "mask", &krule->mask, sizeof(krule->mask));
nvlist_add_bool(nvl, "neg", krule->neg);
return (nvl);