From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- net/ipv4/netfilter/ipt_ULOG.c | 419 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 419 insertions(+) create mode 100644 net/ipv4/netfilter/ipt_ULOG.c (limited to 'net/ipv4/netfilter/ipt_ULOG.c') diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c new file mode 100644 index 00000000000..6f2cefbe16c --- /dev/null +++ b/net/ipv4/netfilter/ipt_ULOG.c @@ -0,0 +1,419 @@ +/* + * netfilter module for userspace packet logging daemons + * + * (C) 2000-2004 by Harald Welte + * + * 2000/09/22 ulog-cprange feature added + * 2001/01/04 in-kernel queue as proposed by Sebastian Zander + * + * 2001/01/30 per-rule nlgroup conflicts with global queue. + * nlgroup now global (sysctl) + * 2001/04/19 ulog-queue reworked, now fixed buffer size specified at + * module loadtime -HW + * 2002/07/07 remove broken nflog_rcv() function -HW + * 2002/08/29 fix shifted/unshifted nlgroup bug -HW + * 2002/10/30 fix uninitialized mac_len field - + * 2004/10/25 fix erroneous calculation of 'len' parameter to NLMSG_PUT + * resulting in bogus 'error during NLMSG_PUT' messages. + * + * (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2004 Netfilter Core Team + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This module accepts two parameters: + * + * nlbufsiz: + * The parameter specifies how big the buffer for each netlink multicast + * group is. e.g. If you say nlbufsiz=8192, up to eight kb of packets will + * get accumulated in the kernel until they are sent to userspace. It is + * NOT possible to allocate more than 128kB, and it is strongly discouraged, + * because atomically allocating 128kB inside the network rx softirq is not + * reliable. Please also keep in mind that this buffer size is allocated for + * each nlgroup you are using, so the total kernel memory usage increases + * by that factor. + * + * flushtimeout: + * Specify, after how many hundredths of a second the queue should be + * flushed even if it is not full yet. + * + * ipt_ULOG.c,v 1.22 2002/10/30 09:07:31 laforge Exp + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Harald Welte "); +MODULE_DESCRIPTION("iptables userspace logging module"); + +#define ULOG_NL_EVENT 111 /* Harald's favorite number */ +#define ULOG_MAXNLGROUPS 32 /* numer of nlgroups */ + +#if 0 +#define DEBUGP(format, args...) printk("%s:%s:" format, \ + __FILE__, __FUNCTION__ , ## args) +#else +#define DEBUGP(format, args...) +#endif + +#define PRINTR(format, args...) do { if (net_ratelimit()) printk(format , ## args); } while (0) + +static unsigned int nlbufsiz = 4096; +module_param(nlbufsiz, uint, 0600); /* FIXME: Check size < 128k --RR */ +MODULE_PARM_DESC(nlbufsiz, "netlink buffer size"); + +static unsigned int flushtimeout = 10; +module_param(flushtimeout, int, 0600); +MODULE_PARM_DESC(flushtimeout, "buffer flush timeout (hundredths of a second)"); + +static unsigned int nflog = 1; +module_param(nflog, int, 0400); +MODULE_PARM_DESC(nflog, "register as internal netfilter logging module"); + +/* global data structures */ + +typedef struct { + unsigned int qlen; /* number of nlmsgs' in the skb */ + struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */ + struct sk_buff *skb; /* the pre-allocated skb */ + struct timer_list timer; /* the timer function */ +} ulog_buff_t; + +static ulog_buff_t ulog_buffers[ULOG_MAXNLGROUPS]; /* array of buffers */ + +static struct sock *nflognl; /* our socket */ +static DECLARE_LOCK(ulog_lock); /* spinlock */ + +/* send one ulog_buff_t to userspace */ +static void ulog_send(unsigned int nlgroupnum) +{ + ulog_buff_t *ub = &ulog_buffers[nlgroupnum]; + + if (timer_pending(&ub->timer)) { + DEBUGP("ipt_ULOG: ulog_send: timer was pending, deleting\n"); + del_timer(&ub->timer); + } + + /* last nlmsg needs NLMSG_DONE */ + if (ub->qlen > 1) + ub->lastnlh->nlmsg_type = NLMSG_DONE; + + NETLINK_CB(ub->skb).dst_groups = (1 << nlgroupnum); + DEBUGP("ipt_ULOG: throwing %d packets to netlink mask %u\n", + ub->qlen, nlgroupnum); + netlink_broadcast(nflognl, ub->skb, 0, (1 << nlgroupnum), GFP_ATOMIC); + + ub->qlen = 0; + ub->skb = NULL; + ub->lastnlh = NULL; + +} + + +/* timer function to flush queue in flushtimeout time */ +static void ulog_timer(unsigned long data) +{ + DEBUGP("ipt_ULOG: timer function called, calling ulog_send\n"); + + /* lock to protect against somebody modifying our structure + * from ipt_ulog_target at the same time */ + LOCK_BH(&ulog_lock); + ulog_send(data); + UNLOCK_BH(&ulog_lock); +} + +static struct sk_buff *ulog_alloc_skb(unsigned int size) +{ + struct sk_buff *skb; + + /* alloc skb which should be big enough for a whole + * multipart message. WARNING: has to be <= 131000 + * due to slab allocator restrictions */ + + skb = alloc_skb(nlbufsiz, GFP_ATOMIC); + if (!skb) { + PRINTR("ipt_ULOG: can't alloc whole buffer %ub!\n", + nlbufsiz); + + /* try to allocate only as much as we need for + * current packet */ + + skb = alloc_skb(size, GFP_ATOMIC); + if (!skb) + PRINTR("ipt_ULOG: can't even allocate %ub\n", size); + } + + return skb; +} + +static void ipt_ulog_packet(unsigned int hooknum, + const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct ipt_ulog_info *loginfo, + const char *prefix) +{ + ulog_buff_t *ub; + ulog_packet_msg_t *pm; + size_t size, copy_len; + struct nlmsghdr *nlh; + + /* ffs == find first bit set, necessary because userspace + * is already shifting groupnumber, but we need unshifted. + * ffs() returns [1..32], we need [0..31] */ + unsigned int groupnum = ffs(loginfo->nl_group) - 1; + + /* calculate the size of the skb needed */ + if ((loginfo->copy_range == 0) || + (loginfo->copy_range > skb->len)) { + copy_len = skb->len; + } else { + copy_len = loginfo->copy_range; + } + + size = NLMSG_SPACE(sizeof(*pm) + copy_len); + + ub = &ulog_buffers[groupnum]; + + LOCK_BH(&ulog_lock); + + if (!ub->skb) { + if (!(ub->skb = ulog_alloc_skb(size))) + goto alloc_failure; + } else if (ub->qlen >= loginfo->qthreshold || + size > skb_tailroom(ub->skb)) { + /* either the queue len is too high or we don't have + * enough room in nlskb left. send it to userspace. */ + + ulog_send(groupnum); + + if (!(ub->skb = ulog_alloc_skb(size))) + goto alloc_failure; + } + + DEBUGP("ipt_ULOG: qlen %d, qthreshold %d\n", ub->qlen, + loginfo->qthreshold); + + /* NLMSG_PUT contains a hidden goto nlmsg_failure !!! */ + nlh = NLMSG_PUT(ub->skb, 0, ub->qlen, ULOG_NL_EVENT, + sizeof(*pm)+copy_len); + ub->qlen++; + + pm = NLMSG_DATA(nlh); + + /* We might not have a timestamp, get one */ + if (skb->stamp.tv_sec == 0) + do_gettimeofday((struct timeval *)&skb->stamp); + + /* copy hook, prefix, timestamp, payload, etc. */ + pm->data_len = copy_len; + pm->timestamp_sec = skb->stamp.tv_sec; + pm->timestamp_usec = skb->stamp.tv_usec; + pm->mark = skb->nfmark; + pm->hook = hooknum; + if (prefix != NULL) + strncpy(pm->prefix, prefix, sizeof(pm->prefix)); + else if (loginfo->prefix[0] != '\0') + strncpy(pm->prefix, loginfo->prefix, sizeof(pm->prefix)); + else + *(pm->prefix) = '\0'; + + if (in && in->hard_header_len > 0 + && skb->mac.raw != (void *) skb->nh.iph + && in->hard_header_len <= ULOG_MAC_LEN) { + memcpy(pm->mac, skb->mac.raw, in->hard_header_len); + pm->mac_len = in->hard_header_len; + } else + pm->mac_len = 0; + + if (in) + strncpy(pm->indev_name, in->name, sizeof(pm->indev_name)); + else + pm->indev_name[0] = '\0'; + + if (out) + strncpy(pm->outdev_name, out->name, sizeof(pm->outdev_name)); + else + pm->outdev_name[0] = '\0'; + + /* copy_len <= skb->len, so can't fail. */ + if (skb_copy_bits(skb, 0, pm->payload, copy_len) < 0) + BUG(); + + /* check if we are building multi-part messages */ + if (ub->qlen > 1) { + ub->lastnlh->nlmsg_flags |= NLM_F_MULTI; + } + + ub->lastnlh = nlh; + + /* if timer isn't already running, start it */ + if (!timer_pending(&ub->timer)) { + ub->timer.expires = jiffies + flushtimeout * HZ / 100; + add_timer(&ub->timer); + } + + /* if threshold is reached, send message to userspace */ + if (ub->qlen >= loginfo->qthreshold) { + if (loginfo->qthreshold > 1) + nlh->nlmsg_type = NLMSG_DONE; + ulog_send(groupnum); + } + + UNLOCK_BH(&ulog_lock); + + return; + +nlmsg_failure: + PRINTR("ipt_ULOG: error during NLMSG_PUT\n"); + +alloc_failure: + PRINTR("ipt_ULOG: Error building netlink message\n"); + + UNLOCK_BH(&ulog_lock); +} + +static unsigned int ipt_ulog_target(struct sk_buff **pskb, + const struct net_device *in, + const struct net_device *out, + unsigned int hooknum, + const void *targinfo, void *userinfo) +{ + struct ipt_ulog_info *loginfo = (struct ipt_ulog_info *) targinfo; + + ipt_ulog_packet(hooknum, *pskb, in, out, loginfo, NULL); + + return IPT_CONTINUE; +} + +static void ipt_logfn(unsigned int hooknum, + const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const char *prefix) +{ + struct ipt_ulog_info loginfo = { + .nl_group = ULOG_DEFAULT_NLGROUP, + .copy_range = 0, + .qthreshold = ULOG_DEFAULT_QTHRESHOLD, + .prefix = "" + }; + + ipt_ulog_packet(hooknum, skb, in, out, &loginfo, prefix); +} + +static int ipt_ulog_checkentry(const char *tablename, + const struct ipt_entry *e, + void *targinfo, + unsigned int targinfosize, + unsigned int hookmask) +{ + struct ipt_ulog_info *loginfo = (struct ipt_ulog_info *) targinfo; + + if (targinfosize != IPT_ALIGN(sizeof(struct ipt_ulog_info))) { + DEBUGP("ipt_ULOG: targinfosize %u != 0\n", targinfosize); + return 0; + } + + if (loginfo->prefix[sizeof(loginfo->prefix) - 1] != '\0') { + DEBUGP("ipt_ULOG: prefix term %i\n", + loginfo->prefix[sizeof(loginfo->prefix) - 1]); + return 0; + } + + if (loginfo->qthreshold > ULOG_MAX_QLEN) { + DEBUGP("ipt_ULOG: queue threshold %i > MAX_QLEN\n", + loginfo->qthreshold); + return 0; + } + + return 1; +} + +static struct ipt_target ipt_ulog_reg = { + .name = "ULOG", + .target = ipt_ulog_target, + .checkentry = ipt_ulog_checkentry, + .me = THIS_MODULE, +}; + +static int __init init(void) +{ + int i; + + DEBUGP("ipt_ULOG: init module\n"); + + if (nlbufsiz >= 128*1024) { + printk("Netlink buffer has to be <= 128kB\n"); + return -EINVAL; + } + + /* initialize ulog_buffers */ + for (i = 0; i < ULOG_MAXNLGROUPS; i++) { + init_timer(&ulog_buffers[i].timer); + ulog_buffers[i].timer.function = ulog_timer; + ulog_buffers[i].timer.data = i; + } + + nflognl = netlink_kernel_create(NETLINK_NFLOG, NULL); + if (!nflognl) + return -ENOMEM; + + if (ipt_register_target(&ipt_ulog_reg) != 0) { + sock_release(nflognl->sk_socket); + return -EINVAL; + } + if (nflog) + nf_log_register(PF_INET, &ipt_logfn); + + return 0; +} + +static void __exit fini(void) +{ + ulog_buff_t *ub; + int i; + + DEBUGP("ipt_ULOG: cleanup_module\n"); + + if (nflog) + nf_log_unregister(PF_INET, &ipt_logfn); + ipt_unregister_target(&ipt_ulog_reg); + sock_release(nflognl->sk_socket); + + /* remove pending timers and free allocated skb's */ + for (i = 0; i < ULOG_MAXNLGROUPS; i++) { + ub = &ulog_buffers[i]; + if (timer_pending(&ub->timer)) { + DEBUGP("timer was pending, deleting\n"); + del_timer(&ub->timer); + } + + if (ub->skb) { + kfree_skb(ub->skb); + ub->skb = NULL; + } + } + +} + +module_init(init); +module_exit(fini); -- cgit v1.2.3