diff options
Diffstat (limited to 'iptables/nft-shared.c')
| -rw-r--r-- | iptables/nft-shared.c | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/iptables/nft-shared.c b/iptables/nft-shared.c new file mode 100644 index 00000000..c368f40b --- /dev/null +++ b/iptables/nft-shared.c @@ -0,0 +1,418 @@ +/* + * (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org> + * (C) 2013 by Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This code has been sponsored by Sophos Astaro <http://www.sophos.com> + */ + +#include <string.h> +#include <stdio.h> +#include <stdbool.h> +#include <netdb.h> + +#include <linux/netfilter/nf_tables.h> + +#include <libmnl/libmnl.h> +#include <libnftables/rule.h> +#include <libnftables/expr.h> + +#include "nft-shared.h" +#include "xshared.h" + +extern struct nft_family_ops nft_family_ops_ipv4; +extern struct nft_family_ops nft_family_ops_ipv6; + +void add_meta(struct nft_rule *r, uint32_t key) +{ + struct nft_rule_expr *expr; + + expr = nft_rule_expr_alloc("meta"); + if (expr == NULL) + return; + + nft_rule_expr_set_u32(expr, NFT_EXPR_META_KEY, key); + nft_rule_expr_set_u32(expr, NFT_EXPR_META_DREG, NFT_REG_1); + + nft_rule_add_expr(r, expr); +} + +void add_payload(struct nft_rule *r, int offset, int len) +{ + struct nft_rule_expr *expr; + + expr = nft_rule_expr_alloc("payload"); + if (expr == NULL) + return; + + nft_rule_expr_set_u32(expr, NFT_EXPR_PAYLOAD_BASE, + NFT_PAYLOAD_NETWORK_HEADER); + nft_rule_expr_set_u32(expr, NFT_EXPR_PAYLOAD_DREG, NFT_REG_1); + nft_rule_expr_set_u32(expr, NFT_EXPR_PAYLOAD_OFFSET, offset); + nft_rule_expr_set_u32(expr, NFT_EXPR_PAYLOAD_LEN, len); + + nft_rule_add_expr(r, expr); +} + +/* bitwise operation is = sreg & mask ^ xor */ +void add_bitwise_u16(struct nft_rule *r, int mask, int xor) +{ + struct nft_rule_expr *expr; + + expr = nft_rule_expr_alloc("bitwise"); + if (expr == NULL) + return; + + nft_rule_expr_set_u32(expr, NFT_EXPR_BITWISE_SREG, NFT_REG_1); + nft_rule_expr_set_u32(expr, NFT_EXPR_BITWISE_DREG, NFT_REG_1); + nft_rule_expr_set_u32(expr, NFT_EXPR_BITWISE_LEN, sizeof(uint16_t)); + nft_rule_expr_set(expr, NFT_EXPR_BITWISE_MASK, &mask, sizeof(uint16_t)); + nft_rule_expr_set(expr, NFT_EXPR_BITWISE_XOR, &xor, sizeof(uint16_t)); + + nft_rule_add_expr(r, expr); +} + +void add_cmp_ptr(struct nft_rule *r, uint32_t op, void *data, size_t len) +{ + struct nft_rule_expr *expr; + + expr = nft_rule_expr_alloc("cmp"); + if (expr == NULL) + return; + + nft_rule_expr_set_u8(expr, NFT_EXPR_CMP_SREG, NFT_REG_1); + nft_rule_expr_set_u8(expr, NFT_EXPR_CMP_OP, op); + nft_rule_expr_set(expr, NFT_EXPR_CMP_DATA, data, len); + + nft_rule_add_expr(r, expr); +} + +void add_cmp_u16(struct nft_rule *r, uint16_t val, uint32_t op) +{ + add_cmp_ptr(r, op, &val, sizeof(val)); +} + +void add_cmp_u32(struct nft_rule *r, uint32_t val, uint32_t op) +{ + add_cmp_ptr(r, op, &val, sizeof(val)); +} + +void add_iniface(struct nft_rule *r, char *iface, int invflags) +{ + int iface_len; + uint32_t op; + + iface_len = strlen(iface); + + if (invflags & IPT_INV_VIA_IN) + op = NFT_CMP_NEQ; + else + op = NFT_CMP_EQ; + + if (iface[iface_len - 1] == '+') { + add_meta(r, NFT_META_IIFNAME); + add_cmp_ptr(r, op, iface, iface_len - 1); + } else { + add_meta(r, NFT_META_IIF); + add_cmp_u32(r, if_nametoindex(iface), op); + } +} + +void add_outiface(struct nft_rule *r, char *iface, int invflags) +{ + int iface_len; + uint32_t op; + + iface_len = strlen(iface); + + if (invflags & IPT_INV_VIA_OUT) + op = NFT_CMP_NEQ; + else + op = NFT_CMP_EQ; + + if (iface[iface_len - 1] == '+') { + add_meta(r, NFT_META_OIFNAME); + add_cmp_ptr(r, op, iface, iface_len - 1); + } else { + add_meta(r, NFT_META_OIF); + add_cmp_u32(r, if_nametoindex(iface), op); + } +} + +void add_addr(struct nft_rule *r, int offset, + void *data, size_t len, int invflags) +{ + uint32_t op; + + add_payload(r, offset, len); + + if (invflags & IPT_INV_SRCIP || invflags & IPT_INV_DSTIP) + op = NFT_CMP_NEQ; + else + op = NFT_CMP_EQ; + + add_cmp_ptr(r, op, data, len); +} + +void add_proto(struct nft_rule *r, int offset, size_t len, + uint32_t proto, int invflags) +{ + uint32_t op; + + add_payload(r, offset, len); + + if (invflags & XT_INV_PROTO) + op = NFT_CMP_NEQ; + else + op = NFT_CMP_EQ; + + add_cmp_u32(r, proto, op); +} + +bool is_same_interfaces(const char *a_iniface, const char *a_outiface, + unsigned const char *a_iniface_mask, + unsigned const char *a_outiface_mask, + const char *b_iniface, const char *b_outiface, + unsigned const char *b_iniface_mask, + unsigned const char *b_outiface_mask) +{ + int i; + + for (i = 0; i < IFNAMSIZ; i++) { + if (a_iniface_mask[i] != b_iniface_mask[i]) { + DEBUGP("different iniface mask %x, %x (%d)\n", + a_iniface_mask[i] & 0xff, b_iniface_mask[i] & 0xff, i); + return false; + } + if ((a_iniface[i] & a_iniface_mask[i]) + != (b_iniface[i] & b_iniface_mask[i])) { + DEBUGP("different iniface\n"); + return false; + } + if (a_outiface_mask[i] != b_outiface_mask[i]) { + DEBUGP("different outiface mask\n"); + return false; + } + if ((a_outiface[i] & a_outiface_mask[i]) + != (b_outiface[i] & b_outiface_mask[i])) { + DEBUGP("different outiface\n"); + return false; + } + } + + return true; +} + +void parse_meta(struct nft_rule_expr *e, uint8_t key, char *iniface, + unsigned char *iniface_mask, char *outiface, + unsigned char *outiface_mask, uint8_t *invflags) +{ + uint32_t value; + const void *ifname; + size_t len; + + switch(key) { + case NFT_META_IIF: + value = nft_rule_expr_get_u32(e, NFT_EXPR_CMP_DATA); + if (nft_rule_expr_get_u8(e, NFT_EXPR_CMP_OP) == NFT_CMP_NEQ) + *invflags |= IPT_INV_VIA_IN; + + if_indextoname(value, iniface); + + memset(iniface_mask, 0xff, strlen(iniface)+1); + break; + case NFT_META_OIF: + value = nft_rule_expr_get_u32(e, NFT_EXPR_CMP_DATA); + if (nft_rule_expr_get_u8(e, NFT_EXPR_CMP_OP) == NFT_CMP_NEQ) + *invflags |= IPT_INV_VIA_OUT; + + if_indextoname(value, outiface); + + memset(outiface_mask, 0xff, strlen(outiface)+1); + break; + case NFT_META_IIFNAME: + ifname = nft_rule_expr_get(e, NFT_EXPR_CMP_DATA, &len); + if (nft_rule_expr_get_u8(e, NFT_EXPR_CMP_OP) == NFT_CMP_NEQ) + *invflags |= IPT_INV_VIA_IN; + + memcpy(iniface, ifname, len); + iniface[len] = '\0'; + + /* If zero, then this is an interface mask */ + if (if_nametoindex(iniface) == 0) { + iniface[len] = '+'; + iniface[len+1] = '\0'; + } + + memset(iniface_mask, 0xff, len); + break; + case NFT_META_OIFNAME: + ifname = nft_rule_expr_get(e, NFT_EXPR_CMP_DATA, &len); + if (nft_rule_expr_get_u8(e, NFT_EXPR_CMP_OP) == NFT_CMP_NEQ) + *invflags |= IPT_INV_VIA_OUT; + + memcpy(outiface, ifname, len); + outiface[len] = '\0'; + + /* If zero, then this is an interface mask */ + if (if_nametoindex(outiface) == 0) { + outiface[len] = '+'; + outiface[len+1] = '\0'; + } + + memset(outiface_mask, 0xff, len); + break; + default: + DEBUGP("unknown meta key %d\n", key); + break; + } +} + +void print_proto(uint16_t proto, int invert) +{ + const struct protoent *pent = getprotobynumber(proto); + + if (invert) + printf("! "); + + if (pent) { + printf("-p %s ", pent->p_name); + return; + } + + printf("-p %u ", proto); +} + +void get_cmp_data(struct nft_rule_expr_iter *iter, + void *data, size_t dlen, bool *inv) +{ + struct nft_rule_expr *e; + const char *name; + size_t len; + uint8_t op; + + e = nft_rule_expr_iter_next(iter); + if (e == NULL) + return; + + name = nft_rule_expr_get_str(e, NFT_RULE_EXPR_ATTR_NAME); + if (strcmp(name, "cmp") != 0) { + DEBUGP("skipping no cmp after meta\n"); + return; + } + + memcpy(data, nft_rule_expr_get(e, NFT_EXPR_CMP_DATA, &len), dlen); + op = nft_rule_expr_get_u8(e, NFT_EXPR_CMP_OP); + if (op == NFT_CMP_NEQ) + *inv = true; + else + *inv = false; +} + +void print_num(uint64_t number, unsigned int format) +{ + if (format & FMT_KILOMEGAGIGA) { + if (number > 99999) { + number = (number + 500) / 1000; + if (number > 9999) { + number = (number + 500) / 1000; + if (number > 9999) { + number = (number + 500) / 1000; + if (number > 9999) { + number = (number + 500) / 1000; + printf(FMT("%4lluT ","%lluT "), (unsigned long long)number); + } + else printf(FMT("%4lluG ","%lluG "), (unsigned long long)number); + } + else printf(FMT("%4lluM ","%lluM "), (unsigned long long)number); + } else + printf(FMT("%4lluK ","%lluK "), (unsigned long long)number); + } else + printf(FMT("%5llu ","%llu "), (unsigned long long)number); + } else + printf(FMT("%8llu ","%llu "), (unsigned long long)number); +} + +void print_firewall_details(const struct iptables_command_state *cs, + const char *targname, uint8_t flags, + uint8_t invflags, uint8_t proto, + const char *iniface, const char *outiface, + unsigned int num, unsigned int format) +{ + if (format & FMT_LINENUMBERS) + printf(FMT("%-4u ", "%u "), num); + + if (!(format & FMT_NOCOUNTS)) { + print_num(cs->counters.pcnt, format); + print_num(cs->counters.bcnt, format); + } + + if (!(format & FMT_NOTARGET)) + printf(FMT("%-9s ", "%s "), targname ? targname : ""); + + fputc(invflags & XT_INV_PROTO ? '!' : ' ', stdout); + { + const char *pname = + proto_to_name(proto, format&FMT_NUMERIC); + if (pname) + printf(FMT("%-5s", "%s "), pname); + else + printf(FMT("%-5hu", "%hu "), proto); + } + + if (format & FMT_OPTIONS) { + if (format & FMT_NOTABLE) + fputs("opt ", stdout); + fputc(invflags & IPT_INV_FRAG ? '!' : '-', stdout); + fputc(flags & IPT_F_FRAG ? 'f' : '-', stdout); + fputc(' ', stdout); + } + + if (format & FMT_VIA) { + char iface[IFNAMSIZ+2]; + if (invflags & IPT_INV_VIA_IN) { + iface[0] = '!'; + iface[1] = '\0'; + } + else iface[0] = '\0'; + + if (iniface[0] != '\0') { + strcat(iface, iniface); + } + else if (format & FMT_NUMERIC) strcat(iface, "*"); + else strcat(iface, "any"); + printf(FMT(" %-6s ","in %s "), iface); + + if (invflags & IPT_INV_VIA_OUT) { + iface[0] = '!'; + iface[1] = '\0'; + } + else iface[0] = '\0'; + + if (outiface[0] != '\0') { + strcat(iface, outiface); + } + else if (format & FMT_NUMERIC) strcat(iface, "*"); + else strcat(iface, "any"); + printf(FMT("%-6s ","out %s "), iface); + } +} + +struct nft_family_ops *nft_family_ops_lookup(int family) +{ + switch (family) { + case AF_INET: + return &nft_family_ops_ipv4; + case AF_INET6: + return &nft_family_ops_ipv6; + default: + break; + } + + return NULL; +} + |