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Diffstat (limited to '')
| -rw-r--r-- | src/expr/tproxy.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/src/expr/tproxy.c b/src/expr/tproxy.c new file mode 100644 index 0000000..bd5ffbf --- /dev/null +++ b/src/expr/tproxy.c @@ -0,0 +1,174 @@ +/* + * Copyright (c) 2018 Máté Eckl <ecklm94@gmail.com> + * + * 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 "internal.h" + +#include <stdio.h> +#include <stdint.h> +#include <limits.h> +#include <string.h> +#include <errno.h> +#include <arpa/inet.h> +#include <libmnl/libmnl.h> +#include <linux/netfilter/nf_tables.h> +#include <libnftnl/expr.h> +#include <libnftnl/rule.h> + +struct nftnl_expr_tproxy { + enum nft_registers sreg_addr; + enum nft_registers sreg_port; + int family; +}; + +static int +nftnl_expr_tproxy_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_TPROXY_FAMILY: + memcpy(&tproxy->family, data, sizeof(tproxy->family)); + break; + case NFTNL_EXPR_TPROXY_REG_ADDR: + memcpy(&tproxy->sreg_addr, data, sizeof(tproxy->sreg_addr)); + break; + case NFTNL_EXPR_TPROXY_REG_PORT: + memcpy(&tproxy->sreg_port, data, sizeof(tproxy->sreg_port)); + break; + default: + return -1; + } + + return 0; +} + +static const void * +nftnl_expr_tproxy_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_TPROXY_FAMILY: + *data_len = sizeof(tproxy->family); + return &tproxy->family; + case NFTNL_EXPR_TPROXY_REG_ADDR: + *data_len = sizeof(tproxy->sreg_addr); + return &tproxy->sreg_addr; + case NFTNL_EXPR_TPROXY_REG_PORT: + *data_len = sizeof(tproxy->sreg_port); + return &tproxy->sreg_port; + } + return NULL; +} + +static int nftnl_expr_tproxy_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_TPROXY_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_TPROXY_FAMILY: + case NFTA_TPROXY_REG_ADDR: + case NFTA_TPROXY_REG_PORT: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static int +nftnl_expr_tproxy_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e); + struct nlattr *tb[NFTA_TPROXY_MAX + 1] = {}; + + if (mnl_attr_parse_nested(attr, nftnl_expr_tproxy_cb, tb) < 0) + return -1; + + if (tb[NFTA_TPROXY_FAMILY]) { + tproxy->family = ntohl(mnl_attr_get_u32(tb[NFTA_TPROXY_FAMILY])); + e->flags |= (1 << NFTNL_EXPR_TPROXY_FAMILY); + } + if (tb[NFTA_TPROXY_REG_ADDR]) { + tproxy->sreg_addr = + ntohl(mnl_attr_get_u32(tb[NFTA_TPROXY_REG_ADDR])); + e->flags |= (1 << NFTNL_EXPR_TPROXY_REG_ADDR); + } + if (tb[NFTA_TPROXY_REG_PORT]) { + tproxy->sreg_port = + ntohl(mnl_attr_get_u32(tb[NFTA_TPROXY_REG_PORT])); + e->flags |= (1 << NFTNL_EXPR_TPROXY_REG_PORT); + } + + return 0; +} + +static void +nftnl_expr_tproxy_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_TPROXY_FAMILY)) + mnl_attr_put_u32(nlh, NFTA_TPROXY_FAMILY, htonl(tproxy->family)); + + if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_ADDR)) + mnl_attr_put_u32(nlh, NFTA_TPROXY_REG_ADDR, + htonl(tproxy->sreg_addr)); + + if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_PORT)) + mnl_attr_put_u32(nlh, NFTA_TPROXY_REG_PORT, + htonl(tproxy->sreg_port)); +} + +static int +nftnl_expr_tproxy_snprintf(char *buf, size_t remain, + uint32_t flags, const struct nftnl_expr *e) +{ + struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e); + int offset = 0, ret = 0; + + if (tproxy->family != NFTA_TPROXY_UNSPEC) { + ret = snprintf(buf + offset, remain, "%s ", + nftnl_family2str(tproxy->family)); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_ADDR)) { + ret = snprintf(buf + offset, remain, + "addr reg %u ", tproxy->sreg_addr); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_PORT)) { + ret = snprintf(buf + offset, remain, + "port reg %u ", tproxy->sreg_port); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + return offset; +} + +struct expr_ops expr_ops_tproxy = { + .name = "tproxy", + .alloc_len = sizeof(struct nftnl_expr_tproxy), + .max_attr = NFTA_TPROXY_MAX, + .set = nftnl_expr_tproxy_set, + .get = nftnl_expr_tproxy_get, + .parse = nftnl_expr_tproxy_parse, + .build = nftnl_expr_tproxy_build, + .output = nftnl_expr_tproxy_snprintf, +}; |