The branch main has been updated by kp: URL: https://cgit.FreeBSD.org/src/commit/?id=b590f17a11aacaeb0a70d075df04d40c6b7eb947
commit b590f17a11aacaeb0a70d075df04d40c6b7eb947 Author: Kristof Provost <[email protected]> AuthorDate: 2022-01-20 17:31:45 +0000 Commit: Kristof Provost <[email protected]> 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);
