Netfilter code (net/netfilter/nft_log.c and net/netfilter/xt_AUDIT.c) have to be kept in sync. Both source files had duplicated versions of audit_ip4() and audit_ip6() functions, which can result in lack of consistency and/or duplicated work.
This patch adds a helper function in audit.c that can be called by netfilter code commonly, aiming to improve maintainability and consistency. Suggested-by: Florian Westphal <[email protected]> Suggested-by: Paul Moore <[email protected]> Signed-off-by: Ricardo Robaina <[email protected]> --- include/linux/audit.h | 8 +++++ kernel/audit.c | 64 ++++++++++++++++++++++++++++++++++++++++ net/netfilter/nft_log.c | 58 +----------------------------------- net/netfilter/xt_AUDIT.c | 58 +----------------------------------- 4 files changed, 74 insertions(+), 114 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 536f8ee8da81..d8173af498ba 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -195,6 +195,8 @@ extern int audit_log_subj_ctx(struct audit_buffer *ab, struct lsm_prop *prop); extern int audit_log_obj_ctx(struct audit_buffer *ab, struct lsm_prop *prop); extern int audit_log_task_context(struct audit_buffer *ab); extern void audit_log_task_info(struct audit_buffer *ab); +extern int audit_log_nf_skb(struct audit_buffer *ab, + const struct sk_buff *skb, u8 nfproto); extern int audit_update_lsm_rules(void); @@ -272,6 +274,12 @@ static inline int audit_log_task_context(struct audit_buffer *ab) static inline void audit_log_task_info(struct audit_buffer *ab) { } +static inline int audit_log_nf_skb(struct audit_buffer *ab, + const struct sk_buff *skb, u8 nfproto) +{ + return 0; +} + static inline kuid_t audit_get_loginuid(struct task_struct *tsk) { return INVALID_UID; diff --git a/kernel/audit.c b/kernel/audit.c index 26a332ffb1b8..5c302c4592db 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -58,6 +58,8 @@ #include <linux/freezer.h> #include <linux/pid_namespace.h> #include <net/netns/generic.h> +#include <net/ip.h> +#include <net/ipv6.h> #include "audit.h" @@ -2488,6 +2490,68 @@ void audit_log_path_denied(int type, const char *operation) audit_log_end(ab); } +int audit_log_nf_skb(struct audit_buffer *ab, + const struct sk_buff *skb, u8 nfproto) +{ + /* find the IP protocol in the case of NFPROTO_BRIDGE */ + if (nfproto == NFPROTO_BRIDGE) { + switch (eth_hdr(skb)->h_proto) { + case htons(ETH_P_IP): + nfproto = NFPROTO_IPV4; + break; + case htons(ETH_P_IPV6): + nfproto = NFPROTO_IPV6; + break; + default: + goto unknown_proto; + } + } + + switch (nfproto) { + case NFPROTO_IPV4: { + struct iphdr iph; + const struct iphdr *ih; + + ih = skb_header_pointer(skb, skb_network_offset(skb), + sizeof(iph), &iph); + if (!ih) + return -ENOMEM; + + audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu", + &ih->saddr, &ih->daddr, ih->protocol); + break; + } + case NFPROTO_IPV6: { + struct ipv6hdr iph; + const struct ipv6hdr *ih; + u8 nexthdr; + __be16 frag_off; + + ih = skb_header_pointer(skb, skb_network_offset(skb), + sizeof(iph), &iph); + if (!ih) + return -ENOMEM; + + nexthdr = ih->nexthdr; + ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(iph), + &nexthdr, &frag_off); + + audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu", + &ih->saddr, &ih->daddr, nexthdr); + break; + } + default: + goto unknown_proto; + } + + return 0; + +unknown_proto: + audit_log_format(ab, " saddr=? daddr=? proto=?"); + return -EPFNOSUPPORT; +} +EXPORT_SYMBOL(audit_log_nf_skb); + /* global counter which is incremented every time something logs in */ static atomic_t session_id = ATOMIC_INIT(0); diff --git a/net/netfilter/nft_log.c b/net/netfilter/nft_log.c index e35588137995..bf01cf8a8907 100644 --- a/net/netfilter/nft_log.c +++ b/net/netfilter/nft_log.c @@ -26,46 +26,10 @@ struct nft_log { char *prefix; }; -static bool audit_ip4(struct audit_buffer *ab, struct sk_buff *skb) -{ - struct iphdr _iph; - const struct iphdr *ih; - - ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_iph), &_iph); - if (!ih) - return false; - - audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu", - &ih->saddr, &ih->daddr, ih->protocol); - - return true; -} - -static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb) -{ - struct ipv6hdr _ip6h; - const struct ipv6hdr *ih; - u8 nexthdr; - __be16 frag_off; - - ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h); - if (!ih) - return false; - - nexthdr = ih->nexthdr; - ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), &nexthdr, &frag_off); - - audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu", - &ih->saddr, &ih->daddr, nexthdr); - - return true; -} - static void nft_log_eval_audit(const struct nft_pktinfo *pkt) { struct sk_buff *skb = pkt->skb; struct audit_buffer *ab; - int fam = -1; if (!audit_enabled) return; @@ -76,27 +40,7 @@ static void nft_log_eval_audit(const struct nft_pktinfo *pkt) audit_log_format(ab, "mark=%#x", skb->mark); - switch (nft_pf(pkt)) { - case NFPROTO_BRIDGE: - switch (eth_hdr(skb)->h_proto) { - case htons(ETH_P_IP): - fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1; - break; - case htons(ETH_P_IPV6): - fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1; - break; - } - break; - case NFPROTO_IPV4: - fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1; - break; - case NFPROTO_IPV6: - fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1; - break; - } - - if (fam == -1) - audit_log_format(ab, " saddr=? daddr=? proto=-1"); + audit_log_nf_skb(ab, skb, nft_pf(pkt)); audit_log_end(ab); } diff --git a/net/netfilter/xt_AUDIT.c b/net/netfilter/xt_AUDIT.c index b6a015aee0ce..4c18606b8654 100644 --- a/net/netfilter/xt_AUDIT.c +++ b/net/netfilter/xt_AUDIT.c @@ -28,46 +28,10 @@ MODULE_ALIAS("ip6t_AUDIT"); MODULE_ALIAS("ebt_AUDIT"); MODULE_ALIAS("arpt_AUDIT"); -static bool audit_ip4(struct audit_buffer *ab, struct sk_buff *skb) -{ - struct iphdr _iph; - const struct iphdr *ih; - - ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_iph), &_iph); - if (!ih) - return false; - - audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu", - &ih->saddr, &ih->daddr, ih->protocol); - - return true; -} - -static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb) -{ - struct ipv6hdr _ip6h; - const struct ipv6hdr *ih; - u8 nexthdr; - __be16 frag_off; - - ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h); - if (!ih) - return false; - - nexthdr = ih->nexthdr; - ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), &nexthdr, &frag_off); - - audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu", - &ih->saddr, &ih->daddr, nexthdr); - - return true; -} - static unsigned int audit_tg(struct sk_buff *skb, const struct xt_action_param *par) { struct audit_buffer *ab; - int fam = -1; if (audit_enabled == AUDIT_OFF) goto errout; @@ -77,27 +41,7 @@ audit_tg(struct sk_buff *skb, const struct xt_action_param *par) audit_log_format(ab, "mark=%#x", skb->mark); - switch (xt_family(par)) { - case NFPROTO_BRIDGE: - switch (eth_hdr(skb)->h_proto) { - case htons(ETH_P_IP): - fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1; - break; - case htons(ETH_P_IPV6): - fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1; - break; - } - break; - case NFPROTO_IPV4: - fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1; - break; - case NFPROTO_IPV6: - fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1; - break; - } - - if (fam == -1) - audit_log_format(ab, " saddr=? daddr=? proto=-1"); + audit_log_nf_skb(ab, skb, xt_family(par)); audit_log_end(ab); -- 2.51.1
