diff options
Diffstat (limited to 'src/expr/byteorder.c')
| -rw-r--r-- | src/expr/byteorder.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/src/expr/byteorder.c b/src/expr/byteorder.c new file mode 100644 index 0000000..89ed0a8 --- /dev/null +++ b/src/expr/byteorder.c @@ -0,0 +1,224 @@ +/* + * (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/expr.h> +#include <libnftnl/rule.h> + +struct nftnl_expr_byteorder { + enum nft_registers sreg; + enum nft_registers dreg; + enum nft_byteorder_ops op; + unsigned int len; + unsigned int size; +}; + +static int +nftnl_expr_byteorder_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_byteorder *byteorder = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_BYTEORDER_SREG: + memcpy(&byteorder->sreg, data, sizeof(byteorder->sreg)); + break; + case NFTNL_EXPR_BYTEORDER_DREG: + memcpy(&byteorder->dreg, data, sizeof(byteorder->dreg)); + break; + case NFTNL_EXPR_BYTEORDER_OP: + memcpy(&byteorder->op, data, sizeof(byteorder->op)); + break; + case NFTNL_EXPR_BYTEORDER_LEN: + memcpy(&byteorder->len, data, sizeof(byteorder->len)); + break; + case NFTNL_EXPR_BYTEORDER_SIZE: + memcpy(&byteorder->size, data, sizeof(byteorder->size)); + break; + default: + return -1; + } + return 0; +} + +static const void * +nftnl_expr_byteorder_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_byteorder *byteorder = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_BYTEORDER_SREG: + *data_len = sizeof(byteorder->sreg); + return &byteorder->sreg; + case NFTNL_EXPR_BYTEORDER_DREG: + *data_len = sizeof(byteorder->dreg); + return &byteorder->dreg; + case NFTNL_EXPR_BYTEORDER_OP: + *data_len = sizeof(byteorder->op); + return &byteorder->op; + case NFTNL_EXPR_BYTEORDER_LEN: + *data_len = sizeof(byteorder->len); + return &byteorder->len; + case NFTNL_EXPR_BYTEORDER_SIZE: + *data_len = sizeof(byteorder->size); + return &byteorder->size; + } + return NULL; +} + +static int nftnl_expr_byteorder_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_BYTEORDER_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_BYTEORDER_SREG: + case NFTA_BYTEORDER_DREG: + case NFTA_BYTEORDER_OP: + case NFTA_BYTEORDER_LEN: + case NFTA_BYTEORDER_SIZE: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_byteorder_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_byteorder *byteorder = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_BYTEORDER_SREG)) { + mnl_attr_put_u32(nlh, NFTA_BYTEORDER_SREG, + htonl(byteorder->sreg)); + } + if (e->flags & (1 << NFTNL_EXPR_BYTEORDER_DREG)) { + mnl_attr_put_u32(nlh, NFTA_BYTEORDER_DREG, + htonl(byteorder->dreg)); + } + if (e->flags & (1 << NFTNL_EXPR_BYTEORDER_OP)) { + mnl_attr_put_u32(nlh, NFTA_BYTEORDER_OP, + htonl(byteorder->op)); + } + if (e->flags & (1 << NFTNL_EXPR_BYTEORDER_LEN)) { + mnl_attr_put_u32(nlh, NFTA_BYTEORDER_LEN, + htonl(byteorder->len)); + } + if (e->flags & (1 << NFTNL_EXPR_BYTEORDER_SIZE)) { + mnl_attr_put_u32(nlh, NFTA_BYTEORDER_SIZE, + htonl(byteorder->size)); + } +} + +static int +nftnl_expr_byteorder_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_byteorder *byteorder = nftnl_expr_data(e); + struct nlattr *tb[NFTA_BYTEORDER_MAX+1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nftnl_expr_byteorder_cb, tb) < 0) + return -1; + + if (tb[NFTA_BYTEORDER_SREG]) { + byteorder->sreg = + ntohl(mnl_attr_get_u32(tb[NFTA_BYTEORDER_SREG])); + e->flags |= (1 << NFTNL_EXPR_BYTEORDER_SREG); + } + if (tb[NFTA_BYTEORDER_DREG]) { + byteorder->dreg = + ntohl(mnl_attr_get_u32(tb[NFTA_BYTEORDER_DREG])); + e->flags |= (1 << NFTNL_EXPR_BYTEORDER_DREG); + } + if (tb[NFTA_BYTEORDER_OP]) { + byteorder->op = + ntohl(mnl_attr_get_u32(tb[NFTA_BYTEORDER_OP])); + e->flags |= (1 << NFTNL_EXPR_BYTEORDER_OP); + } + if (tb[NFTA_BYTEORDER_LEN]) { + byteorder->len = + ntohl(mnl_attr_get_u32(tb[NFTA_BYTEORDER_LEN])); + e->flags |= (1 << NFTNL_EXPR_BYTEORDER_LEN); + } + if (tb[NFTA_BYTEORDER_SIZE]) { + byteorder->size = + ntohl(mnl_attr_get_u32(tb[NFTA_BYTEORDER_SIZE])); + e->flags |= (1 << NFTNL_EXPR_BYTEORDER_SIZE); + } + + return ret; +} + +static const char *expr_byteorder_str[] = { + [NFT_BYTEORDER_HTON] = "hton", + [NFT_BYTEORDER_NTOH] = "ntoh", +}; + +static const char *bo2str(uint32_t type) +{ + if (type > NFT_BYTEORDER_HTON) + return "unknown"; + + return expr_byteorder_str[type]; +} + +static inline int nftnl_str2ntoh(const char *op) +{ + if (strcmp(op, "ntoh") == 0) + return NFT_BYTEORDER_NTOH; + else if (strcmp(op, "hton") == 0) + return NFT_BYTEORDER_HTON; + else { + errno = EINVAL; + return -1; + } +} + +static int +nftnl_expr_byteorder_snprintf(char *buf, size_t remain, + uint32_t flags, const struct nftnl_expr *e) +{ + struct nftnl_expr_byteorder *byteorder = nftnl_expr_data(e); + int offset = 0, ret; + + ret = snprintf(buf, remain, "reg %u = %s(reg %u, %u, %u) ", + byteorder->dreg, bo2str(byteorder->op), + byteorder->sreg, byteorder->size, byteorder->len); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + + return offset; +} + +struct expr_ops expr_ops_byteorder = { + .name = "byteorder", + .alloc_len = sizeof(struct nftnl_expr_byteorder), + .max_attr = NFTA_BYTEORDER_MAX, + .set = nftnl_expr_byteorder_set, + .get = nftnl_expr_byteorder_get, + .parse = nftnl_expr_byteorder_parse, + .build = nftnl_expr_byteorder_build, + .output = nftnl_expr_byteorder_snprintf, +}; |