X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=net%2Fnetfilter%2Fnfnetlink.c;h=032224c1409f02e658daa77898f3ab764b62e779;hb=7c8d4cb4198d199e65a6ced8c81f71e3ac3f4cfc;hp=11d504d0ac72068d8c88bc794fe4cb8c1284e3d9;hpb=cd354f1ae75e6466a7e31b727faede57a1f89ca5;p=linux-2.6 diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 11d504d0ac..032224c140 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -3,7 +3,7 @@ * * (C) 2001 by Jay Schulist , * (C) 2002-2005 by Harald Welte - * (C) 2005 by Pablo Neira Ayuso + * (C) 2005,2007 by Pablo Neira Ayuso * * Initial netfilter messages via netlink development funded and * generally made possible by Network Robots, Inc. (www.networkrobots.com) @@ -28,10 +28,9 @@ #include #include #include +#include #include -#include -#include #include #include @@ -41,32 +40,34 @@ MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER); static char __initdata nfversion[] = "0.30"; -#if 0 -#define DEBUGP(format, args...) \ - printk(KERN_DEBUG "%s(%d):%s(): " format, __FILE__, \ - __LINE__, __FUNCTION__, ## args) -#else -#define DEBUGP(format, args...) -#endif - static struct sock *nfnl = NULL; -static struct nfnetlink_subsystem *subsys_table[NFNL_SUBSYS_COUNT]; -DECLARE_MUTEX(nfnl_sem); +static const struct nfnetlink_subsystem *subsys_table[NFNL_SUBSYS_COUNT]; +static DEFINE_MUTEX(nfnl_mutex); -void nfnl_lock(void) +static void nfnl_lock(void) { - nfnl_shlock(); + mutex_lock(&nfnl_mutex); } -void nfnl_unlock(void) +static int nfnl_trylock(void) { - nfnl_shunlock(); + return !mutex_trylock(&nfnl_mutex); } -int nfnetlink_subsys_register(struct nfnetlink_subsystem *n) +static void __nfnl_unlock(void) { - DEBUGP("registering subsystem ID %u\n", n->subsys_id); + mutex_unlock(&nfnl_mutex); +} +static void nfnl_unlock(void) +{ + mutex_unlock(&nfnl_mutex); + if (nfnl->sk_receive_queue.qlen) + nfnl->sk_data_ready(nfnl, 0); +} + +int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n) +{ nfnl_lock(); if (subsys_table[n->subsys_id]) { nfnl_unlock(); @@ -77,38 +78,35 @@ int nfnetlink_subsys_register(struct nfnetlink_subsystem *n) return 0; } +EXPORT_SYMBOL_GPL(nfnetlink_subsys_register); -int nfnetlink_subsys_unregister(struct nfnetlink_subsystem *n) +int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n) { - DEBUGP("unregistering subsystem ID %u\n", n->subsys_id); - nfnl_lock(); subsys_table[n->subsys_id] = NULL; nfnl_unlock(); return 0; } +EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister); -static inline struct nfnetlink_subsystem *nfnetlink_get_subsys(u_int16_t type) +static inline const struct nfnetlink_subsystem *nfnetlink_get_subsys(u_int16_t type) { u_int8_t subsys_id = NFNL_SUBSYS_ID(type); - if (subsys_id >= NFNL_SUBSYS_COUNT - || subsys_table[subsys_id] == NULL) + if (subsys_id >= NFNL_SUBSYS_COUNT) return NULL; return subsys_table[subsys_id]; } -static inline struct nfnl_callback * -nfnetlink_find_client(u_int16_t type, struct nfnetlink_subsystem *ss) +static inline const struct nfnl_callback * +nfnetlink_find_client(u_int16_t type, const struct nfnetlink_subsystem *ss) { u_int8_t cb_id = NFNL_MSG_TYPE(type); - if (cb_id >= ss->cb_count) { - DEBUGP("msgtype %u >= %u, returning\n", type, ss->cb_count); + if (cb_id >= ss->cb_count) return NULL; - } return &ss->cb[cb_id]; } @@ -125,6 +123,7 @@ void __nfa_fill(struct sk_buff *skb, int attrtype, int attrlen, memcpy(NFA_DATA(nfa), data, attrlen); memset(NFA_DATA(nfa) + attrlen, 0, NFA_ALIGN(size) - size); } +EXPORT_SYMBOL_GPL(__nfa_fill); void nfattr_parse(struct nfattr *tb[], int maxattr, struct nfattr *nfa, int len) { @@ -137,6 +136,7 @@ void nfattr_parse(struct nfattr *tb[], int maxattr, struct nfattr *nfa, int len) nfa = NFA_NEXT(nfa, len); } } +EXPORT_SYMBOL_GPL(nfattr_parse); /** * nfnetlink_check_attributes - check and parse nfnetlink attributes @@ -147,40 +147,18 @@ void nfattr_parse(struct nfattr *tb[], int maxattr, struct nfattr *nfa, int len) * */ static int -nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys, +nfnetlink_check_attributes(const struct nfnetlink_subsystem *subsys, struct nlmsghdr *nlh, struct nfattr *cda[]) { - int min_len; - u_int16_t attr_count; + int min_len = NLMSG_SPACE(sizeof(struct nfgenmsg)); u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); - - if (unlikely(cb_id >= subsys->cb_count)) { - DEBUGP("msgtype %u >= %u, returning\n", - cb_id, subsys->cb_count); - return -EINVAL; - } - - min_len = NLMSG_SPACE(sizeof(struct nfgenmsg)); - if (unlikely(nlh->nlmsg_len < min_len)) - return -EINVAL; - - attr_count = subsys->cb[cb_id].attr_count; - memset(cda, 0, sizeof(struct nfattr *) * attr_count); + u_int16_t attr_count = subsys->cb[cb_id].attr_count; /* check attribute lengths. */ if (likely(nlh->nlmsg_len > min_len)) { struct nfattr *attr = NFM_NFA(NLMSG_DATA(nlh)); int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len); - - while (NFA_OK(attr, attrlen)) { - unsigned flavor = NFA_TYPE(attr); - if (flavor) { - if (flavor > attr_count) - return -EINVAL; - cda[flavor - 1] = attr; - } - attr = NFA_NEXT(attr, attrlen); - } + nfattr_parse(cda, attr_count, attr, attrlen); } /* implicit: if nlmsg_len == min_len, we return 0, and an empty @@ -197,74 +175,57 @@ EXPORT_SYMBOL_GPL(nfnetlink_has_listeners); int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo) { - gfp_t allocation = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL; int err = 0; NETLINK_CB(skb).dst_group = group; if (echo) atomic_inc(&skb->users); - netlink_broadcast(nfnl, skb, pid, group, allocation); + netlink_broadcast(nfnl, skb, pid, group, gfp_any()); if (echo) err = netlink_unicast(nfnl, skb, pid, MSG_DONTWAIT); return err; } +EXPORT_SYMBOL_GPL(nfnetlink_send); int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags) { return netlink_unicast(nfnl, skb, pid, flags); } +EXPORT_SYMBOL_GPL(nfnetlink_unicast); /* Process one complete nfnetlink message. */ -static int nfnetlink_rcv_msg(struct sk_buff *skb, - struct nlmsghdr *nlh, int *errp) +static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) { - struct nfnl_callback *nc; - struct nfnetlink_subsystem *ss; - int type, err = 0; - - DEBUGP("entered; subsys=%u, msgtype=%u\n", - NFNL_SUBSYS_ID(nlh->nlmsg_type), - NFNL_MSG_TYPE(nlh->nlmsg_type)); - - if (security_netlink_recv(skb, CAP_NET_ADMIN)) { - DEBUGP("missing CAP_NET_ADMIN\n"); - *errp = -EPERM; - return -1; - } + const struct nfnl_callback *nc; + const struct nfnetlink_subsystem *ss; + int type, err; - /* Only requests are handled by kernel now. */ - if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) { - DEBUGP("received non-request message\n"); - return 0; - } + if (security_netlink_recv(skb, CAP_NET_ADMIN)) + return -EPERM; /* All the messages must at least contain nfgenmsg */ - if (nlh->nlmsg_len < NLMSG_SPACE(sizeof(struct nfgenmsg))) { - DEBUGP("received message was too short\n"); + if (nlh->nlmsg_len < NLMSG_SPACE(sizeof(struct nfgenmsg))) return 0; - } type = nlh->nlmsg_type; ss = nfnetlink_get_subsys(type); if (!ss) { #ifdef CONFIG_KMOD - /* don't call nfnl_shunlock, since it would reenter + /* don't call nfnl_unlock, since it would reenter * with further packet processing */ - up(&nfnl_sem); + __nfnl_unlock(); request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); - nfnl_shlock(); + nfnl_lock(); ss = nfnetlink_get_subsys(type); if (!ss) #endif - goto err_inval; + return -EINVAL; } nc = nfnetlink_find_client(type, ss); - if (!nc) { - DEBUGP("unable to find client for type %d\n", type); - goto err_inval; - } + if (!nc) + return -EINVAL; { u_int16_t attr_count = @@ -275,73 +236,21 @@ static int nfnetlink_rcv_msg(struct sk_buff *skb, err = nfnetlink_check_attributes(ss, nlh, cda); if (err < 0) - goto err_inval; - - DEBUGP("calling handler\n"); - err = nc->call(nfnl, skb, nlh, cda, errp); - *errp = err; - return err; + return err; + return nc->call(nfnl, skb, nlh, cda); } - -err_inval: - DEBUGP("returning -EINVAL\n"); - *errp = -EINVAL; - return -1; -} - -/* Process one packet of messages. */ -static inline int nfnetlink_rcv_skb(struct sk_buff *skb) -{ - int err; - struct nlmsghdr *nlh; - - while (skb->len >= NLMSG_SPACE(0)) { - u32 rlen; - - nlh = (struct nlmsghdr *)skb->data; - if (nlh->nlmsg_len < sizeof(struct nlmsghdr) - || skb->len < nlh->nlmsg_len) - return 0; - rlen = NLMSG_ALIGN(nlh->nlmsg_len); - if (rlen > skb->len) - rlen = skb->len; - if (nfnetlink_rcv_msg(skb, nlh, &err)) { - if (!err) - return -1; - netlink_ack(skb, nlh, err); - } else - if (nlh->nlmsg_flags & NLM_F_ACK) - netlink_ack(skb, nlh, 0); - skb_pull(skb, rlen); - } - - return 0; } static void nfnetlink_rcv(struct sock *sk, int len) { - do { - struct sk_buff *skb; + unsigned int qlen = 0; - if (nfnl_shlock_nowait()) + do { + if (nfnl_trylock()) return; - - while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { - if (nfnetlink_rcv_skb(skb)) { - if (skb->len) - skb_queue_head(&sk->sk_receive_queue, - skb); - else - kfree_skb(skb); - break; - } - kfree_skb(skb); - } - - /* don't call nfnl_shunlock, since it would reenter - * with further packet processing */ - up(&nfnl_sem); - } while(nfnl && nfnl->sk_receive_queue.qlen); + qlen = netlink_run_queue(sk, qlen, nfnetlink_rcv_msg); + __nfnl_unlock(); + } while (qlen); } static void __exit nfnetlink_exit(void) @@ -355,8 +264,8 @@ static int __init nfnetlink_init(void) { printk("Netfilter messages via NETLINK v%s.\n", nfversion); - nfnl = netlink_kernel_create(NETLINK_NETFILTER, NFNLGRP_MAX, - nfnetlink_rcv, THIS_MODULE); + nfnl = netlink_kernel_create(&init_net, NETLINK_NETFILTER, NFNLGRP_MAX, + nfnetlink_rcv, NULL, THIS_MODULE); if (!nfnl) { printk(KERN_ERR "cannot initialize nfnetlink!\n"); return -1; @@ -367,10 +276,3 @@ static int __init nfnetlink_init(void) module_init(nfnetlink_init); module_exit(nfnetlink_exit); - -EXPORT_SYMBOL_GPL(nfnetlink_subsys_register); -EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister); -EXPORT_SYMBOL_GPL(nfnetlink_send); -EXPORT_SYMBOL_GPL(nfnetlink_unicast); -EXPORT_SYMBOL_GPL(nfattr_parse); -EXPORT_SYMBOL_GPL(__nfa_fill);