X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=net%2Fnetfilter%2Fnfnetlink.c;h=b75c9c4a995d885c1ac12339b0afff9d1d24db31;hb=2bc780499aa33311ec0f3e42624dfaa7be0ade5e;hp=bf23e489e4cdc88eec4a81a8c3461ac2cd5008ee;hpb=cb2ebc59ff52cee770cfd6ba5f23a6cc3c214648;p=~andy%2Flinux diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index bf23e489e4c..b75c9c4a995 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 +40,22 @@ 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 inline void nfnl_lock(void) { - nfnl_shlock(); + mutex_lock(&nfnl_mutex); } -void nfnl_unlock(void) +static inline void nfnl_unlock(void) { - nfnl_shunlock(); + mutex_unlock(&nfnl_mutex); } -int nfnetlink_subsys_register(struct nfnetlink_subsystem *n) +int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n) { - DEBUGP("registering subsystem ID %u\n", n->subsys_id); - nfnl_lock(); if (subsys_table[n->subsys_id]) { nfnl_unlock(); @@ -77,118 +66,39 @@ 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]; } -void __nfa_fill(struct sk_buff *skb, int attrtype, int attrlen, - const void *data) -{ - struct nfattr *nfa; - int size = NFA_LENGTH(attrlen); - - nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size)); - nfa->nfa_type = attrtype; - nfa->nfa_len = size; - memcpy(NFA_DATA(nfa), data, attrlen); - memset(NFA_DATA(nfa) + attrlen, 0, NFA_ALIGN(size) - size); -} - -void nfattr_parse(struct nfattr *tb[], int maxattr, struct nfattr *nfa, int len) -{ - memset(tb, 0, sizeof(struct nfattr *) * maxattr); - - while (NFA_OK(nfa, len)) { - unsigned flavor = NFA_TYPE(nfa); - if (flavor && flavor <= maxattr) - tb[flavor-1] = nfa; - nfa = NFA_NEXT(nfa, len); - } -} - -/** - * nfnetlink_check_attributes - check and parse nfnetlink attributes - * - * subsys: nfnl subsystem for which this message is to be parsed - * nlmsghdr: netlink message to be checked/parsed - * cda: array of pointers, needs to be at least subsys->attr_count big - * - */ -static int -nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys, - struct nlmsghdr *nlh, struct nfattr *cda[]) -{ - int min_len; - u_int16_t attr_count; - 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); - - /* 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); - } - } - - /* implicit: if nlmsg_len == min_len, we return 0, and an empty - * (zeroed) cda[] array. The message is valid, but empty. */ - - return 0; -} - int nfnetlink_has_listeners(unsigned int group) { return netlink_has_listeners(nfnl, group); @@ -197,156 +107,79 @@ EXPORT_SYMBOL_GPL(nfnetlink_has_listeners); int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo) { - int err = 0; - - NETLINK_CB(skb).dst_group = group; - if (echo) - atomic_inc(&skb->users); - netlink_broadcast(nfnl, skb, pid, group, gfp_any()); - if (echo) - err = netlink_unicast(nfnl, skb, pid, MSG_DONTWAIT); - - return err; + return nlmsg_notify(nfnl, skb, pid, group, echo, gfp_any()); } +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)); + const struct nfnl_callback *nc; + const struct nfnetlink_subsystem *ss; + int type, err; - if (security_netlink_recv(skb, CAP_NET_ADMIN)) { - DEBUGP("missing CAP_NET_ADMIN\n"); - *errp = -EPERM; - return -1; - } - - /* 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 - * 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 = - ss->cb[NFNL_MSG_TYPE(nlh->nlmsg_type)].attr_count; - struct nfattr *cda[attr_count]; - - memset(cda, 0, sizeof(struct nfattr *) * attr_count); - - 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; - } - -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); + int min_len = NLMSG_SPACE(sizeof(struct nfgenmsg)); + u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); + u_int16_t attr_count = ss->cb[cb_id].attr_count; + struct nlattr *cda[attr_count+1]; + + if (likely(nlh->nlmsg_len >= min_len)) { + struct nlattr *attr = (void *)nlh + NLMSG_ALIGN(min_len); + int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len); + + err = nla_parse(cda, attr_count, attr, attrlen, + ss->cb[cb_id].policy); + if (err < 0) + return err; } else - if (nlh->nlmsg_flags & NLM_F_ACK) - netlink_ack(skb, nlh, 0); - skb_pull(skb, rlen); - } + return -EINVAL; - return 0; + return nc->call(nfnl, skb, nlh, cda); + } } -static void nfnetlink_rcv(struct sock *sk, int len) +static void nfnetlink_rcv(struct sk_buff *skb) { - do { - struct sk_buff *skb; - - if (nfnl_shlock_nowait()) - 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); + nfnl_lock(); + netlink_rcv_skb(skb, &nfnetlink_rcv_msg); + nfnl_unlock(); } static void __exit nfnetlink_exit(void) { printk("Removing netfilter NETLINK layer.\n"); - sock_release(nfnl->sk_socket); + netlink_kernel_release(nfnl); return; } @@ -354,8 +187,8 @@ 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; @@ -366,10 +199,3 @@ 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);