diff options
Diffstat (limited to 'src/expr/log.c')
| -rw-r--r-- | src/expr/log.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/src/expr/log.c b/src/expr/log.c new file mode 100644 index 0000000..180d839 --- /dev/null +++ b/src/expr/log.c @@ -0,0 +1,257 @@ +/* + * (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 <stdio.h> +#include <stdint.h> +#include <string.h> +#include <arpa/inet.h> +#include <errno.h> +#include <linux/netfilter/nf_tables.h> +#include <linux/netfilter/nf_log.h> + +#include "internal.h" +#include <libmnl/libmnl.h> +#include <libnftnl/expr.h> +#include <libnftnl/rule.h> + +struct nftnl_expr_log { + uint32_t snaplen; + uint16_t group; + uint16_t qthreshold; + uint32_t level; + uint32_t flags; + const char *prefix; +}; + +static int nftnl_expr_log_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_log *log = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_LOG_PREFIX: + if (log->flags & (1 << NFTNL_EXPR_LOG_PREFIX)) + xfree(log->prefix); + + log->prefix = strdup(data); + if (!log->prefix) + return -1; + break; + case NFTNL_EXPR_LOG_GROUP: + memcpy(&log->group, data, sizeof(log->group)); + break; + case NFTNL_EXPR_LOG_SNAPLEN: + memcpy(&log->snaplen, data, sizeof(log->snaplen)); + break; + case NFTNL_EXPR_LOG_QTHRESHOLD: + memcpy(&log->qthreshold, data, sizeof(log->qthreshold)); + break; + case NFTNL_EXPR_LOG_LEVEL: + memcpy(&log->level, data, sizeof(log->level)); + break; + case NFTNL_EXPR_LOG_FLAGS: + memcpy(&log->flags, data, sizeof(log->flags)); + break; + default: + return -1; + } + return 0; +} + +static const void * +nftnl_expr_log_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_log *log = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_LOG_PREFIX: + *data_len = strlen(log->prefix)+1; + return log->prefix; + case NFTNL_EXPR_LOG_GROUP: + *data_len = sizeof(log->group); + return &log->group; + case NFTNL_EXPR_LOG_SNAPLEN: + *data_len = sizeof(log->snaplen); + return &log->snaplen; + case NFTNL_EXPR_LOG_QTHRESHOLD: + *data_len = sizeof(log->qthreshold); + return &log->qthreshold; + case NFTNL_EXPR_LOG_LEVEL: + *data_len = sizeof(log->level); + return &log->level; + case NFTNL_EXPR_LOG_FLAGS: + *data_len = sizeof(log->flags); + return &log->flags; + } + return NULL; +} + +static int nftnl_expr_log_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_LOG_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_LOG_PREFIX: + if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) + abi_breakage(); + break; + case NFTA_LOG_GROUP: + case NFTA_LOG_QTHRESHOLD: + if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0) + abi_breakage(); + break; + case NFTA_LOG_SNAPLEN: + case NFTA_LOG_LEVEL: + case NFTA_LOG_FLAGS: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_log_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_log *log = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX)) + mnl_attr_put_strz(nlh, NFTA_LOG_PREFIX, log->prefix); + if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP)) + mnl_attr_put_u16(nlh, NFTA_LOG_GROUP, htons(log->group)); + if (e->flags & (1 << NFTNL_EXPR_LOG_SNAPLEN)) + mnl_attr_put_u32(nlh, NFTA_LOG_SNAPLEN, htonl(log->snaplen)); + if (e->flags & (1 << NFTNL_EXPR_LOG_QTHRESHOLD)) + mnl_attr_put_u16(nlh, NFTA_LOG_QTHRESHOLD, htons(log->qthreshold)); + if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL)) + mnl_attr_put_u32(nlh, NFTA_LOG_LEVEL, htonl(log->level)); + if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS)) + mnl_attr_put_u32(nlh, NFTA_LOG_FLAGS, htonl(log->flags)); +} + +static int +nftnl_expr_log_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_log *log = nftnl_expr_data(e); + struct nlattr *tb[NFTA_LOG_MAX+1] = {}; + + if (mnl_attr_parse_nested(attr, nftnl_expr_log_cb, tb) < 0) + return -1; + + if (tb[NFTA_LOG_PREFIX]) { + if (log->prefix) + xfree(log->prefix); + + log->prefix = strdup(mnl_attr_get_str(tb[NFTA_LOG_PREFIX])); + if (!log->prefix) + return -1; + e->flags |= (1 << NFTNL_EXPR_LOG_PREFIX); + } + if (tb[NFTA_LOG_GROUP]) { + log->group = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_GROUP])); + e->flags |= (1 << NFTNL_EXPR_LOG_GROUP); + } + if (tb[NFTA_LOG_SNAPLEN]) { + log->snaplen = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_SNAPLEN])); + e->flags |= (1 << NFTNL_EXPR_LOG_SNAPLEN); + } + if (tb[NFTA_LOG_QTHRESHOLD]) { + log->qthreshold = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_QTHRESHOLD])); + e->flags |= (1 << NFTNL_EXPR_LOG_QTHRESHOLD); + } + if (tb[NFTA_LOG_LEVEL]) { + log->level = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_LEVEL])); + e->flags |= (1 << NFTNL_EXPR_LOG_LEVEL); + } + if (tb[NFTA_LOG_FLAGS]) { + log->flags = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_FLAGS])); + e->flags |= (1 << NFTNL_EXPR_LOG_FLAGS); + } + + return 0; +} + +static int +nftnl_expr_log_snprintf(char *buf, size_t remain, + uint32_t flags, const struct nftnl_expr *e) +{ + struct nftnl_expr_log *log = nftnl_expr_data(e); + int ret, offset = 0; + + if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX)) { + ret = snprintf(buf, remain, "prefix %s ", log->prefix); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP)) { + ret = snprintf(buf + offset, remain, + "group %u snaplen %u qthreshold %u ", + log->group, log->snaplen, log->qthreshold); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } else { + if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL)) { + ret = snprintf(buf + offset, remain, "level %u ", + log->level); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS)) { + if (log->flags & NF_LOG_TCPSEQ) { + ret = snprintf(buf + offset, remain, "tcpseq "); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + if (log->flags & NF_LOG_TCPOPT) { + ret = snprintf(buf + offset, remain, "tcpopt "); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + if (log->flags & NF_LOG_IPOPT) { + ret = snprintf(buf + offset, remain, "ipopt "); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + if (log->flags & NF_LOG_UID) { + ret = snprintf(buf + offset, remain, "uid "); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + if (log->flags & NF_LOG_MACDECODE) { + ret = snprintf(buf + offset, remain, + "macdecode "); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + } + } + + return offset; +} + +static void nftnl_expr_log_free(const struct nftnl_expr *e) +{ + struct nftnl_expr_log *log = nftnl_expr_data(e); + + xfree(log->prefix); +} + +struct expr_ops expr_ops_log = { + .name = "log", + .alloc_len = sizeof(struct nftnl_expr_log), + .max_attr = NFTA_LOG_MAX, + .free = nftnl_expr_log_free, + .set = nftnl_expr_log_set, + .get = nftnl_expr_log_get, + .parse = nftnl_expr_log_parse, + .build = nftnl_expr_log_build, + .output = nftnl_expr_log_snprintf, +}; |