From 00c179b4c9f9f9394cc6f79e5f2a68410631fd72 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Fri, 3 Aug 2012 17:31:48 +0200 Subject: initial version of libnftables It adds support for table, chain and rule handling. This also includes expression handling for each rule. Signed-off-by: Pablo Neira Ayuso --- src/table.c | 212 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 212 insertions(+) create mode 100644 src/table.c (limited to 'src/table.c') diff --git a/src/table.c b/src/table.c new file mode 100644 index 0000000..040bf9a --- /dev/null +++ b/src/table.c @@ -0,0 +1,212 @@ +/* + * (C) 2012 by Pablo Neira Ayuso + * + * 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 + */ +#include "internal.h" + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include + +struct nft_table { + struct list_head head; + + char *name; + uint8_t family; + uint32_t flags; /* FIXME missing */ +}; + +struct nft_table *nft_table_alloc(void) +{ + return calloc(1, sizeof(struct nft_table)); +} +EXPORT_SYMBOL(nft_table_alloc); + +void nft_table_free(struct nft_table *t) +{ + if (t->name != NULL) + free(t->name); + + free(t); +} +EXPORT_SYMBOL(nft_table_free); + +void nft_table_attr_set(struct nft_table *t, uint16_t attr, void *data) +{ + switch(attr) { + case NFT_TABLE_ATTR_NAME: + if (t->name) + free(t->name); + + t->name = strdup(data); + break; + } +} +EXPORT_SYMBOL(nft_table_attr_set); + +const void *nft_table_attr_get(struct nft_table *t, uint16_t attr) +{ + switch(attr) { + case NFT_TABLE_ATTR_NAME: + return t->name; + } + return NULL; +} +EXPORT_SYMBOL(nft_table_attr_get); + +struct nlmsghdr * +nft_table_nlmsg_build_hdr(char *buf, uint16_t cmd, uint16_t family, + uint16_t type, uint32_t seq) +{ + struct nlmsghdr *nlh; + struct nfgenmsg *nfh; + + nlh = mnl_nlmsg_put_header(buf); + nlh->nlmsg_type = (NFNL_SUBSYS_NFTABLES << 8) | cmd; + nlh->nlmsg_flags = NLM_F_REQUEST | type; + nlh->nlmsg_seq = seq; + + nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg)); + nfh->nfgen_family = family; + nfh->version = NFNETLINK_V0; + nfh->res_id = 0; + + return nlh; +} +EXPORT_SYMBOL(nft_table_nlmsg_build_hdr); + +void nft_table_nlmsg_build_payload(struct nlmsghdr *nlh, const struct nft_table *t) +{ + if (t->name != NULL) + mnl_attr_put_strz(nlh, NFTA_TABLE_NAME, t->name); +} +EXPORT_SYMBOL(nft_table_nlmsg_build_payload); + +static int nft_table_parse_attr_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_TABLE_MAX) < 0) + return MNL_CB_OK; + + if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +int nft_table_nlmsg_parse(const struct nlmsghdr *nlh, struct nft_table *t) +{ + struct nlattr *tb[NFTA_TABLE_MAX+1] = {}; + struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh); + + mnl_attr_parse(nlh, sizeof(*nfg), nft_table_parse_attr_cb, tb); + if (tb[NFTA_TABLE_NAME]) + t->name = strdup(mnl_attr_get_str(tb[NFTA_TABLE_NAME])); + + t->family = nfg->nfgen_family; + + return 0; +} +EXPORT_SYMBOL(nft_table_nlmsg_parse); + +int nft_table_snprintf(char *buf, size_t size, struct nft_table *t, + uint32_t type, uint32_t flags) +{ + return snprintf(buf, size, "table=%s family=%u\n", t->name, t->family); +} +EXPORT_SYMBOL(nft_table_snprintf); + +struct nft_table_list { + struct list_head list; +}; + +struct nft_table_list *nft_table_list_alloc(void) +{ + struct nft_table_list *list; + + list = calloc(1, sizeof(struct nft_table_list)); + if (list == NULL) + return NULL; + + INIT_LIST_HEAD(&list->list); + + return list; +} +EXPORT_SYMBOL(nft_table_list_alloc); + +void nft_table_list_free(struct nft_table_list *list) +{ + struct nft_table *r, *tmp; + + list_for_each_entry_safe(r, tmp, &list->list, head) { + list_del(&r->head); + nft_table_free(r); + } + free(list); +} +EXPORT_SYMBOL(nft_table_list_free); + +void nft_table_list_add(struct nft_table *r, struct nft_table_list *list) +{ + list_add_tail(&r->head, &list->list); +} +EXPORT_SYMBOL(nft_table_list_add); + +struct nft_table_list_iter { + struct nft_table_list *list; + struct nft_table *cur; +}; + +struct nft_table_list_iter *nft_table_list_iter_create(struct nft_table_list *l) +{ + struct nft_table_list_iter *iter; + + iter = calloc(1, sizeof(struct nft_table_list_iter)); + if (iter == NULL) + return NULL; + + iter->list = l; + iter->cur = list_entry(l->list.next, struct nft_table, head); + + return iter; +} +EXPORT_SYMBOL(nft_table_list_iter_create); + +struct nft_table *nft_table_list_iter_next(struct nft_table_list_iter *iter) +{ + struct nft_table *r = iter->cur; + + /* get next table, if any */ + iter->cur = list_entry(iter->cur->head.next, struct nft_table, head); + if (&iter->cur->head == iter->list->list.next) + return NULL; + + return r; +} +EXPORT_SYMBOL(nft_table_list_iter_next); + +void nft_table_list_iter_destroy(struct nft_table_list_iter *iter) +{ + free(iter); +} +EXPORT_SYMBOL(nft_table_list_iter_destroy); -- cgit v1.2.3