diff options
Diffstat (limited to 'src/expr/data_reg.c')
| -rw-r--r-- | src/expr/data_reg.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/src/expr/data_reg.c b/src/expr/data_reg.c new file mode 100644 index 0000000..2633a77 --- /dev/null +++ b/src/expr/data_reg.c @@ -0,0 +1,219 @@ +/* + * (C) 2012 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 <stdio.h> +#include <stdint.h> +#include <string.h> +#include <limits.h> +#include <arpa/inet.h> +#include <errno.h> +#include <netinet/in.h> + +#include <libmnl/libmnl.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <libnftnl/expr.h> +#include <libnftnl/rule.h> +#include "internal.h" + +static int +nftnl_data_reg_value_snprintf_default(char *buf, size_t remain, + const union nftnl_data_reg *reg, + uint32_t flags) +{ + const char *pfx = flags & DATA_F_NOPFX ? "" : "0x"; + int offset = 0, ret, i; + + + + for (i = 0; i < div_round_up(reg->len, sizeof(uint32_t)); i++) { + ret = snprintf(buf + offset, remain, + "%s%.8x ", pfx, reg->val[i]); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + return offset; +} + +static int +nftnl_data_reg_verdict_snprintf_def(char *buf, size_t size, + const union nftnl_data_reg *reg, + uint32_t flags) +{ + int remain = size, offset = 0, ret = 0; + + ret = snprintf(buf, size, "%s ", nftnl_verdict2str(reg->verdict)); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + + if (reg->chain != NULL) { + ret = snprintf(buf + offset, remain, "-> %s ", reg->chain); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + return offset; +} + +int nftnl_data_reg_snprintf(char *buf, size_t size, + const union nftnl_data_reg *reg, + uint32_t flags, int reg_type) +{ + switch(reg_type) { + case DATA_VALUE: + return nftnl_data_reg_value_snprintf_default(buf, size, + reg, flags); + case DATA_VERDICT: + case DATA_CHAIN: + return nftnl_data_reg_verdict_snprintf_def(buf, size, + reg, flags); + default: + return -1; + } +} + +static int nftnl_data_parse_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_DATA_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_DATA_VALUE: + if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0) + abi_breakage(); + break; + case NFTA_DATA_VERDICT: + if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0) + abi_breakage(); + break; + } + tb[type] = attr; + return MNL_CB_OK; +} + +static int nftnl_verdict_parse_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_VERDICT_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_VERDICT_CODE: + case NFTA_VERDICT_CHAIN_ID: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + case NFTA_VERDICT_CHAIN: + if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) + abi_breakage(); + break; + } + tb[type] = attr; + return MNL_CB_OK; +} + +static int +nftnl_parse_verdict(union nftnl_data_reg *data, const struct nlattr *attr, int *type) +{ + struct nlattr *tb[NFTA_VERDICT_MAX+1]; + + if (mnl_attr_parse_nested(attr, nftnl_verdict_parse_cb, tb) < 0) + return -1; + + if (!tb[NFTA_VERDICT_CODE]) + return -1; + + data->verdict = ntohl(mnl_attr_get_u32(tb[NFTA_VERDICT_CODE])); + + switch(data->verdict) { + case NF_ACCEPT: + case NF_DROP: + case NF_QUEUE: + case NFT_CONTINUE: + case NFT_BREAK: + case NFT_RETURN: + if (type) + *type = DATA_VERDICT; + data->len = sizeof(data->verdict); + break; + case NFT_JUMP: + case NFT_GOTO: + if (!tb[NFTA_VERDICT_CHAIN]) + return -1; + + data->chain = strdup(mnl_attr_get_str(tb[NFTA_VERDICT_CHAIN])); + if (!data->chain) + return -1; + + if (type) + *type = DATA_CHAIN; + break; + default: + return -1; + } + + return 0; +} + +static int +__nftnl_parse_data(union nftnl_data_reg *data, const struct nlattr *attr) +{ + void *orig = mnl_attr_get_payload(attr); + uint32_t data_len = mnl_attr_get_payload_len(attr); + + if (data_len == 0) + return -1; + + if (data_len > sizeof(data->val)) + return -1; + + memcpy(data->val, orig, data_len); + data->len = data_len; + + return 0; +} + +int nftnl_parse_data(union nftnl_data_reg *data, struct nlattr *attr, int *type) +{ + struct nlattr *tb[NFTA_DATA_MAX+1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nftnl_data_parse_cb, tb) < 0) + return -1; + + if (tb[NFTA_DATA_VALUE]) { + if (type) + *type = DATA_VALUE; + + ret = __nftnl_parse_data(data, tb[NFTA_DATA_VALUE]); + if (ret < 0) + return ret; + } + if (tb[NFTA_DATA_VERDICT]) + ret = nftnl_parse_verdict(data, tb[NFTA_DATA_VERDICT], type); + + return ret; +} + +void nftnl_free_verdict(const union nftnl_data_reg *data) +{ + switch(data->verdict) { + case NFT_JUMP: + case NFT_GOTO: + xfree(data->chain); + break; + default: + break; + } +} |