diff options
Diffstat (limited to 'src/expr/lookup.c')
| -rw-r--r-- | src/expr/lookup.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/src/expr/lookup.c b/src/expr/lookup.c new file mode 100644 index 0000000..a06c338 --- /dev/null +++ b/src/expr/lookup.c @@ -0,0 +1,210 @@ +/* + * (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org> + * + * 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 "internal.h" + +#include <stdio.h> +#include <stdint.h> +#include <string.h> /* for memcpy */ +#include <arpa/inet.h> +#include <errno.h> +#include <libmnl/libmnl.h> +#include <linux/netfilter/nf_tables.h> +#include <libnftnl/rule.h> +#include <libnftnl/expr.h> + +struct nftnl_expr_lookup { + enum nft_registers sreg; + enum nft_registers dreg; + char *set_name; + uint32_t set_id; + uint32_t flags; +}; + +static int +nftnl_expr_lookup_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_lookup *lookup = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_LOOKUP_SREG: + memcpy(&lookup->sreg, data, sizeof(lookup->sreg)); + break; + case NFTNL_EXPR_LOOKUP_DREG: + memcpy(&lookup->dreg, data, sizeof(lookup->dreg)); + break; + case NFTNL_EXPR_LOOKUP_SET: + lookup->set_name = strdup((const char *)data); + if (!lookup->set_name) + return -1; + break; + case NFTNL_EXPR_LOOKUP_SET_ID: + memcpy(&lookup->set_id, data, sizeof(lookup->set_id)); + break; + case NFTNL_EXPR_LOOKUP_FLAGS: + memcpy(&lookup->flags, data, sizeof(lookup->flags)); + break; + default: + return -1; + } + return 0; +} + +static const void * +nftnl_expr_lookup_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_lookup *lookup = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_LOOKUP_SREG: + *data_len = sizeof(lookup->sreg); + return &lookup->sreg; + case NFTNL_EXPR_LOOKUP_DREG: + *data_len = sizeof(lookup->dreg); + return &lookup->dreg; + case NFTNL_EXPR_LOOKUP_SET: + *data_len = strlen(lookup->set_name) + 1; + return lookup->set_name; + case NFTNL_EXPR_LOOKUP_SET_ID: + *data_len = sizeof(lookup->set_id); + return &lookup->set_id; + case NFTNL_EXPR_LOOKUP_FLAGS: + *data_len = sizeof(lookup->flags); + return &lookup->flags; + } + return NULL; +} + +static int nftnl_expr_lookup_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, NFTA_LOOKUP_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_LOOKUP_SREG: + case NFTA_LOOKUP_DREG: + case NFTA_LOOKUP_SET_ID: + case NFTA_LOOKUP_FLAGS: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + case NFTA_LOOKUP_SET: + if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_lookup_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_lookup *lookup = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_LOOKUP_SREG)) + mnl_attr_put_u32(nlh, NFTA_LOOKUP_SREG, htonl(lookup->sreg)); + if (e->flags & (1 << NFTNL_EXPR_LOOKUP_DREG)) + mnl_attr_put_u32(nlh, NFTA_LOOKUP_DREG, htonl(lookup->dreg)); + if (e->flags & (1 << NFTNL_EXPR_LOOKUP_SET)) + mnl_attr_put_strz(nlh, NFTA_LOOKUP_SET, lookup->set_name); + if (e->flags & (1 << NFTNL_EXPR_LOOKUP_SET_ID)) + mnl_attr_put_u32(nlh, NFTA_LOOKUP_SET_ID, + htonl(lookup->set_id)); + if (e->flags & (1 << NFTNL_EXPR_LOOKUP_FLAGS)) + mnl_attr_put_u32(nlh, NFTA_LOOKUP_FLAGS, htonl(lookup->flags)); +} + +static int +nftnl_expr_lookup_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_lookup *lookup = nftnl_expr_data(e); + struct nlattr *tb[NFTA_LOOKUP_MAX+1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nftnl_expr_lookup_cb, tb) < 0) + return -1; + + if (tb[NFTA_LOOKUP_SREG]) { + lookup->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_LOOKUP_SREG])); + e->flags |= (1 << NFTNL_EXPR_LOOKUP_SREG); + } + if (tb[NFTA_LOOKUP_DREG]) { + lookup->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_LOOKUP_DREG])); + e->flags |= (1 << NFTNL_EXPR_LOOKUP_DREG); + } + if (tb[NFTA_LOOKUP_SET]) { + lookup->set_name = + strdup(mnl_attr_get_str(tb[NFTA_LOOKUP_SET])); + if (!lookup->set_name) + return -1; + e->flags |= (1 << NFTNL_EXPR_LOOKUP_SET); + } + if (tb[NFTA_LOOKUP_SET_ID]) { + lookup->set_id = + ntohl(mnl_attr_get_u32(tb[NFTA_LOOKUP_SET_ID])); + e->flags |= (1 << NFTNL_EXPR_LOOKUP_SET_ID); + } + if (tb[NFTA_LOOKUP_FLAGS]) { + lookup->flags = ntohl(mnl_attr_get_u32(tb[NFTA_LOOKUP_FLAGS])); + e->flags |= (1 << NFTNL_EXPR_LOOKUP_FLAGS); + } + + return ret; +} + +static int +nftnl_expr_lookup_snprintf(char *buf, size_t remain, + uint32_t flags, const struct nftnl_expr *e) +{ + struct nftnl_expr_lookup *l = nftnl_expr_data(e); + int offset = 0, ret; + + ret = snprintf(buf, remain, "reg %u set %s ", l->sreg, l->set_name); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + + if (e->flags & (1 << NFTNL_EXPR_LOOKUP_DREG)) { + ret = snprintf(buf + offset, remain, "dreg %u ", l->dreg); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + if (e->flags & (1 << NFTNL_EXPR_LOOKUP_FLAGS)) { + ret = snprintf(buf + offset, remain, "0x%x ", l->flags); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + return offset; +} + +static void nftnl_expr_lookup_free(const struct nftnl_expr *e) +{ + struct nftnl_expr_lookup *lookup = nftnl_expr_data(e); + + xfree(lookup->set_name); +} + +struct expr_ops expr_ops_lookup = { + .name = "lookup", + .alloc_len = sizeof(struct nftnl_expr_lookup), + .max_attr = NFTA_LOOKUP_MAX, + .free = nftnl_expr_lookup_free, + .set = nftnl_expr_lookup_set, + .get = nftnl_expr_lookup_get, + .parse = nftnl_expr_lookup_parse, + .build = nftnl_expr_lookup_build, + .output = nftnl_expr_lookup_snprintf, +}; |