From b9f78f9fca626875af8adc0f7366a38b8e625a0e Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 22 Mar 2006 13:56:08 -0800 Subject: [PATCH] [NETFILTER]: nf_conntrack: support for layer 3 protocol load on demand x_tables matches and targets that require nf_conntrack_ipv[4|6] to work don't have enough information to load on demand these modules. This patch introduces the following changes to solve this issue: o nf_ct_l3proto_try_module_get: try to load the layer 3 connection tracker module and increases the refcount. o nf_ct_l3proto_module put: drop the refcount of the module. Signed-off-by: Pablo Neira Ayuso Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/net/netfilter/nf_conntrack.h | 4 +++ .../netfilter/nf_conntrack_l3proto_ipv4.c | 1 + .../netfilter/nf_conntrack_l3proto_ipv6.c | 1 + net/netfilter/nf_conntrack_core.c | 31 +++++++++++++++++++ net/netfilter/nf_conntrack_standalone.c | 2 ++ net/netfilter/xt_connmark.c | 17 ++++++++++ net/netfilter/xt_conntrack.c | 28 +++++++++++++++++ net/netfilter/xt_helper.c | 17 ++++++++++ net/netfilter/xt_state.c | 29 +++++++++++++++++ 9 files changed, 130 insertions(+) diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h index 2743c156caa..b6f0905a4ee 100644 --- a/include/net/netfilter/nf_conntrack.h +++ b/include/net/netfilter/nf_conntrack.h @@ -195,6 +195,10 @@ static inline void nf_ct_put(struct nf_conn *ct) nf_conntrack_put(&ct->ct_general); } +/* Protocol module loading */ +extern int nf_ct_l3proto_try_module_get(unsigned short l3proto); +extern void nf_ct_l3proto_module_put(unsigned short l3proto); + extern struct nf_conntrack_tuple_hash * __nf_conntrack_find(const struct nf_conntrack_tuple *tuple, const struct nf_conn *ignored_conntrack); diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c index cb9c661f3f3..c8abc9d859b 100644 --- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c +++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c @@ -568,6 +568,7 @@ static int init_or_cleanup(int init) return ret; } +MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET)); MODULE_LICENSE("GPL"); static int __init init(void) diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c index ac35f952636..c16f62934bd 100644 --- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c +++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c @@ -584,6 +584,7 @@ static int init_or_cleanup(int init) return ret; } +MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6)); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI "); diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index c2884065645..0ae281d9bfc 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -23,6 +23,8 @@ * 26 Jan 2006: Harald Welte * - restructure nf_conn (introduce nf_conn_help) * - redesign 'features' how they were originally intended + * 26 Feb 2006: Pablo Neira Ayuso + * - add support for L3 protocol module load on demand. * * Derived from net/ipv4/netfilter/ip_conntrack_core.c */ @@ -241,6 +243,35 @@ void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p) module_put(p->me); } +int +nf_ct_l3proto_try_module_get(unsigned short l3proto) +{ + int ret; + struct nf_conntrack_l3proto *p; + +retry: p = nf_ct_l3proto_find_get(l3proto); + if (p == &nf_conntrack_generic_l3proto) { + ret = request_module("nf_conntrack-%d", l3proto); + if (!ret) + goto retry; + + return -EPROTOTYPE; + } + + return 0; +} + +void nf_ct_l3proto_module_put(unsigned short l3proto) +{ + struct nf_conntrack_l3proto *p; + + preempt_disable(); + p = __nf_ct_l3proto_find(l3proto); + preempt_enable(); + + module_put(p->me); +} + static int nf_conntrack_hash_rnd_initted; static unsigned int nf_conntrack_hash_rnd; diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index 290d5a0c559..75577e175b3 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -834,6 +834,8 @@ EXPORT_SYMBOL_GPL(__nf_ct_event_cache_init); EXPORT_PER_CPU_SYMBOL_GPL(nf_conntrack_ecache); EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events); #endif +EXPORT_SYMBOL(nf_ct_l3proto_try_module_get); +EXPORT_SYMBOL(nf_ct_l3proto_module_put); EXPORT_SYMBOL(nf_conntrack_l3proto_register); EXPORT_SYMBOL(nf_conntrack_l3proto_unregister); EXPORT_SYMBOL(nf_conntrack_protocol_register); diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c index e810600345e..7b16f1ee16b 100644 --- a/net/netfilter/xt_connmark.c +++ b/net/netfilter/xt_connmark.c @@ -64,14 +64,30 @@ checkentry(const char *tablename, printk(KERN_WARNING "connmark: only support 32bit mark\n"); return 0; } +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + if (nf_ct_l3proto_try_module_get(match->family) < 0) { + printk(KERN_WARNING "can't load nf_conntrack support for " + "proto=%d\n", match->family); + return 0; + } +#endif return 1; } +static void +destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize) +{ +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + nf_ct_l3proto_module_put(match->family); +#endif +} + static struct xt_match connmark_match = { .name = "connmark", .match = match, .matchsize = sizeof(struct xt_connmark_info), .checkentry = checkentry, + .destroy = destroy, .family = AF_INET, .me = THIS_MODULE }; @@ -81,6 +97,7 @@ static struct xt_match connmark6_match = { .match = match, .matchsize = sizeof(struct xt_connmark_info), .checkentry = checkentry, + .destroy = destroy, .family = AF_INET6, .me = THIS_MODULE }; diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c index 7d20caa0d60..65a84809fd3 100644 --- a/net/netfilter/xt_conntrack.c +++ b/net/netfilter/xt_conntrack.c @@ -203,9 +203,37 @@ match(const struct sk_buff *skb, #endif /* CONFIG_NF_IP_CONNTRACK */ +static int +checkentry(const char *tablename, + const void *ip, + const struct xt_match *match, + void *matchinfo, + unsigned int matchsize, + unsigned int hook_mask) +{ +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + if (nf_ct_l3proto_try_module_get(match->family) < 0) { + printk(KERN_WARNING "can't load nf_conntrack support for " + "proto=%d\n", match->family); + return 0; + } +#endif + return 1; +} + +static void +destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize) +{ +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + nf_ct_l3proto_module_put(match->family); +#endif +} + static struct xt_match conntrack_match = { .name = "conntrack", .match = match, + .checkentry = checkentry, + .destroy = destroy, .matchsize = sizeof(struct xt_conntrack_info), .family = AF_INET, .me = THIS_MODULE, diff --git a/net/netfilter/xt_helper.c b/net/netfilter/xt_helper.c index 7d2d68b9155..101f0005e98 100644 --- a/net/netfilter/xt_helper.c +++ b/net/netfilter/xt_helper.c @@ -144,15 +144,31 @@ static int check(const char *tablename, { struct xt_helper_info *info = matchinfo; +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + if (nf_ct_l3proto_try_module_get(match->family) < 0) { + printk(KERN_WARNING "can't load nf_conntrack support for " + "proto=%d\n", match->family); + return 0; + } +#endif info->name[29] = '\0'; return 1; } +static void +destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize) +{ +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + nf_ct_l3proto_module_put(match->family); +#endif +} + static struct xt_match helper_match = { .name = "helper", .match = match, .matchsize = sizeof(struct xt_helper_info), .checkentry = check, + .destroy = destroy, .family = AF_INET, .me = THIS_MODULE, }; @@ -161,6 +177,7 @@ static struct xt_match helper6_match = { .match = match, .matchsize = sizeof(struct xt_helper_info), .checkentry = check, + .destroy = destroy, .family = AF_INET6, .me = THIS_MODULE, }; diff --git a/net/netfilter/xt_state.c b/net/netfilter/xt_state.c index 7cd557c932b..e6c0be9d94d 100644 --- a/net/netfilter/xt_state.c +++ b/net/netfilter/xt_state.c @@ -44,9 +44,36 @@ match(const struct sk_buff *skb, return (sinfo->statemask & statebit); } +static int check(const char *tablename, + const void *inf, + const struct xt_match *match, + void *matchinfo, + unsigned int matchsize, + unsigned int hook_mask) +{ +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + if (nf_ct_l3proto_try_module_get(match->family) < 0) { + printk(KERN_WARNING "can't load nf_conntrack support for " + "proto=%d\n", match->family); + return 0; + } +#endif + return 1; +} + +static void +destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize) +{ +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + nf_ct_l3proto_module_put(match->family); +#endif +} + static struct xt_match state_match = { .name = "state", .match = match, + .checkentry = check, + .destroy = destroy, .matchsize = sizeof(struct xt_state_info), .family = AF_INET, .me = THIS_MODULE, @@ -55,6 +82,8 @@ static struct xt_match state_match = { static struct xt_match state6_match = { .name = "state", .match = match, + .checkentry = check, + .destroy = destroy, .matchsize = sizeof(struct xt_state_info), .family = AF_INET6, .me = THIS_MODULE, -- 2.20.1