From 01fbc1574b9eec352528b5e6a909d8c6b61633d2 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 17 Dec 2019 18:16:54 +0100 Subject: exthdr: add parse and build userdata interface Add support for meta userdata area. Signed-off-by: Pablo Neira Ayuso Signed-off-by: Florian Westphal --- src/expression.c | 1 + src/exthdr.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 75 insertions(+) diff --git a/src/expression.c b/src/expression.c index a79c6f55..847c88ee 100644 --- a/src/expression.c +++ b/src/expression.c @@ -1227,6 +1227,7 @@ const struct expr_ops *expr_ops_by_type(enum expr_types etype) { switch (etype) { case EXPR_PAYLOAD: return &payload_expr_ops; + case EXPR_EXTHDR: return &exthdr_expr_ops; case EXPR_META: return &meta_expr_ops; default: break; diff --git a/src/exthdr.c b/src/exthdr.c index 925b5232..0b23e0d3 100644 --- a/src/exthdr.c +++ b/src/exthdr.c @@ -91,6 +91,78 @@ static void exthdr_expr_clone(struct expr *new, const struct expr *expr) new->exthdr.flags = expr->exthdr.flags; } +#define NFTNL_UDATA_EXTHDR_DESC 0 +#define NFTNL_UDATA_EXTHDR_TYPE 1 +#define NFTNL_UDATA_EXTHDR_MAX 2 + +static int exthdr_parse_udata(const struct nftnl_udata *attr, void *data) +{ + const struct nftnl_udata **ud = data; + uint8_t type = nftnl_udata_type(attr); + uint8_t len = nftnl_udata_len(attr); + + switch (type) { + case NFTNL_UDATA_EXTHDR_DESC: + case NFTNL_UDATA_EXTHDR_TYPE: + if (len != sizeof(uint32_t)) + return -1; + break; + default: + return 0; + } + + ud[type] = attr; + return 0; +} + +static struct expr *exthdr_expr_parse_udata(const struct nftnl_udata *attr) +{ + const struct nftnl_udata *ud[NFTNL_UDATA_EXTHDR_MAX + 1] = {}; + const struct exthdr_desc *desc; + unsigned int type; + uint32_t desc_id; + int err; + + err = nftnl_udata_parse(nftnl_udata_get(attr), nftnl_udata_len(attr), + exthdr_parse_udata, ud); + if (err < 0) + return NULL; + + if (!ud[NFTNL_UDATA_EXTHDR_DESC] || + !ud[NFTNL_UDATA_EXTHDR_TYPE]) + return NULL; + + desc_id = nftnl_udata_get_u32(ud[NFTNL_UDATA_EXTHDR_DESC]); + desc = exthdr_find_desc(desc_id); + if (!desc) + return NULL; + + type = nftnl_udata_get_u32(ud[NFTNL_UDATA_EXTHDR_TYPE]); + + return exthdr_expr_alloc(&internal_location, desc, type); +} + +static unsigned int expr_exthdr_type(const struct exthdr_desc *desc, + const struct proto_hdr_template *tmpl) +{ + unsigned int offset = (unsigned int)(tmpl - &desc->templates[0]); + + return offset / sizeof(*tmpl); +} + +static int exthdr_expr_build_udata(struct nftnl_udata_buf *udbuf, + const struct expr *expr) +{ + const struct proto_hdr_template *tmpl = expr->exthdr.tmpl; + const struct exthdr_desc *desc = expr->exthdr.desc; + unsigned int type = expr_exthdr_type(desc, tmpl); + + nftnl_udata_put_u32(udbuf, NFTNL_UDATA_EXTHDR_DESC, desc->id); + nftnl_udata_put_u32(udbuf, NFTNL_UDATA_EXTHDR_TYPE, type); + + return 0; +} + const struct expr_ops exthdr_expr_ops = { .type = EXPR_EXTHDR, .name = "exthdr", @@ -98,6 +170,8 @@ const struct expr_ops exthdr_expr_ops = { .json = exthdr_expr_json, .cmp = exthdr_expr_cmp, .clone = exthdr_expr_clone, + .build_udata = exthdr_expr_build_udata, + .parse_udata = exthdr_expr_parse_udata, }; static const struct proto_hdr_template exthdr_unknown_template = -- cgit v1.2.3