diff options
Diffstat (limited to 'src/expr/masq.c')
| -rw-r--r-- | src/expr/masq.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/expr/masq.c b/src/expr/masq.c new file mode 100644 index 0000000..e6e528d --- /dev/null +++ b/src/expr/masq.c @@ -0,0 +1,167 @@ +/* + * (C) 2014 by Arturo Borrero Gonzalez <arturo@debian.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. + */ + +#include <stdio.h> +#include <stdint.h> +#include <arpa/inet.h> +#include <errno.h> +#include <inttypes.h> + +#include <linux/netfilter/nf_tables.h> + +#include "internal.h" +#include <libmnl/libmnl.h> +#include <libnftnl/expr.h> +#include <libnftnl/rule.h> + +struct nftnl_expr_masq { + uint32_t flags; + enum nft_registers sreg_proto_min; + enum nft_registers sreg_proto_max; +}; + +static int +nftnl_expr_masq_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_masq *masq = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_MASQ_FLAGS: + memcpy(&masq->flags, data, sizeof(masq->flags)); + break; + case NFTNL_EXPR_MASQ_REG_PROTO_MIN: + memcpy(&masq->sreg_proto_min, data, sizeof(masq->sreg_proto_min)); + break; + case NFTNL_EXPR_MASQ_REG_PROTO_MAX: + memcpy(&masq->sreg_proto_max, data, sizeof(masq->sreg_proto_max)); + break; + default: + return -1; + } + return 0; +} + +static const void * +nftnl_expr_masq_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_masq *masq = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_MASQ_FLAGS: + *data_len = sizeof(masq->flags); + return &masq->flags; + case NFTNL_EXPR_MASQ_REG_PROTO_MIN: + *data_len = sizeof(masq->sreg_proto_min); + return &masq->sreg_proto_min; + case NFTNL_EXPR_MASQ_REG_PROTO_MAX: + *data_len = sizeof(masq->sreg_proto_max); + return &masq->sreg_proto_max; + } + return NULL; +} + +static int nftnl_expr_masq_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_MASQ_MAX) < 0) + return MNL_CB_OK; + + switch (type) { + case NFTA_MASQ_REG_PROTO_MIN: + case NFTA_MASQ_REG_PROTO_MAX: + case NFTA_MASQ_FLAGS: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_masq_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_masq *masq = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_MASQ_FLAGS)) + mnl_attr_put_u32(nlh, NFTA_MASQ_FLAGS, htobe32(masq->flags)); + if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN)) + mnl_attr_put_u32(nlh, NFTA_MASQ_REG_PROTO_MIN, + htobe32(masq->sreg_proto_min)); + if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX)) + mnl_attr_put_u32(nlh, NFTA_MASQ_REG_PROTO_MAX, + htobe32(masq->sreg_proto_max)); +} + +static int +nftnl_expr_masq_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_masq *masq = nftnl_expr_data(e); + struct nlattr *tb[NFTA_MASQ_MAX+1] = {}; + + if (mnl_attr_parse_nested(attr, nftnl_expr_masq_cb, tb) < 0) + return -1; + + if (tb[NFTA_MASQ_FLAGS]) { + masq->flags = be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_FLAGS])); + e->flags |= (1 << NFTNL_EXPR_MASQ_FLAGS); + } + if (tb[NFTA_MASQ_REG_PROTO_MIN]) { + masq->sreg_proto_min = + be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_REG_PROTO_MIN])); + e->flags |= (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN); + } + if (tb[NFTA_MASQ_REG_PROTO_MAX]) { + masq->sreg_proto_max = + be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_REG_PROTO_MAX])); + e->flags |= (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX); + } + + return 0; +} + +static int nftnl_expr_masq_snprintf(char *buf, size_t remain, + uint32_t flags, const struct nftnl_expr *e) +{ + struct nftnl_expr_masq *masq = nftnl_expr_data(e); + int offset = 0, ret = 0; + + if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN)) { + ret = snprintf(buf + offset, remain, "proto_min reg %u ", + masq->sreg_proto_min); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX)) { + ret = snprintf(buf + offset, remain, "proto_max reg %u ", + masq->sreg_proto_max); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + if (e->flags & (1 << NFTNL_EXPR_MASQ_FLAGS)) { + ret = snprintf(buf + offset, remain, "flags 0x%x ", masq->flags); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + return offset; +} + +struct expr_ops expr_ops_masq = { + .name = "masq", + .alloc_len = sizeof(struct nftnl_expr_masq), + .max_attr = NFTA_MASQ_MAX, + .set = nftnl_expr_masq_set, + .get = nftnl_expr_masq_get, + .parse = nftnl_expr_masq_parse, + .build = nftnl_expr_masq_build, + .output = nftnl_expr_masq_snprintf, +}; |