| /* Kernel module to match various things tied to sockets associated with |
| locally generated outgoing packets. */ |
| |
| /* (C) 2000-2001 Marc Boucher <marc@mbsi.ca> |
| * |
| * 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. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/skbuff.h> |
| #include <linux/file.h> |
| #include <net/sock.h> |
| |
| #include <linux/netfilter_ipv6/ip6t_owner.h> |
| #include <linux/netfilter_ipv6/ip6_tables.h> |
| |
| MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>"); |
| MODULE_DESCRIPTION("IP6 tables owner matching module"); |
| MODULE_LICENSE("GPL"); |
| |
| static int |
| match_pid(const struct sk_buff *skb, pid_t pid) |
| { |
| struct task_struct *p; |
| struct files_struct *files; |
| int i; |
| |
| read_lock(&tasklist_lock); |
| p = find_task_by_pid(pid); |
| if (!p) |
| goto out; |
| task_lock(p); |
| files = p->files; |
| if(files) { |
| spin_lock(&files->file_lock); |
| for (i=0; i < files->max_fds; i++) { |
| if (fcheck_files(files, i) == skb->sk->sk_socket->file) { |
| spin_unlock(&files->file_lock); |
| task_unlock(p); |
| read_unlock(&tasklist_lock); |
| return 1; |
| } |
| } |
| spin_unlock(&files->file_lock); |
| } |
| task_unlock(p); |
| out: |
| read_unlock(&tasklist_lock); |
| return 0; |
| } |
| |
| static int |
| match_sid(const struct sk_buff *skb, pid_t sid) |
| { |
| struct task_struct *g, *p; |
| struct file *file = skb->sk->sk_socket->file; |
| int i, found=0; |
| |
| read_lock(&tasklist_lock); |
| do_each_thread(g, p) { |
| struct files_struct *files; |
| if (p->signal->session != sid) |
| continue; |
| |
| task_lock(p); |
| files = p->files; |
| if (files) { |
| spin_lock(&files->file_lock); |
| for (i=0; i < files->max_fds; i++) { |
| if (fcheck_files(files, i) == file) { |
| found = 1; |
| break; |
| } |
| } |
| spin_unlock(&files->file_lock); |
| } |
| task_unlock(p); |
| if (found) |
| goto out; |
| } while_each_thread(g, p); |
| out: |
| read_unlock(&tasklist_lock); |
| |
| return found; |
| } |
| |
| static int |
| match(const struct sk_buff *skb, |
| const struct net_device *in, |
| const struct net_device *out, |
| const void *matchinfo, |
| int offset, |
| unsigned int protoff, |
| int *hotdrop) |
| { |
| const struct ip6t_owner_info *info = matchinfo; |
| |
| if (!skb->sk || !skb->sk->sk_socket || !skb->sk->sk_socket->file) |
| return 0; |
| |
| if(info->match & IP6T_OWNER_UID) { |
| if((skb->sk->sk_socket->file->f_uid != info->uid) ^ |
| !!(info->invert & IP6T_OWNER_UID)) |
| return 0; |
| } |
| |
| if(info->match & IP6T_OWNER_GID) { |
| if((skb->sk->sk_socket->file->f_gid != info->gid) ^ |
| !!(info->invert & IP6T_OWNER_GID)) |
| return 0; |
| } |
| |
| if(info->match & IP6T_OWNER_PID) { |
| if (!match_pid(skb, info->pid) ^ |
| !!(info->invert & IP6T_OWNER_PID)) |
| return 0; |
| } |
| |
| if(info->match & IP6T_OWNER_SID) { |
| if (!match_sid(skb, info->sid) ^ |
| !!(info->invert & IP6T_OWNER_SID)) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| static int |
| checkentry(const char *tablename, |
| const struct ip6t_ip6 *ip, |
| void *matchinfo, |
| unsigned int matchsize, |
| unsigned int hook_mask) |
| { |
| if (hook_mask |
| & ~((1 << NF_IP6_LOCAL_OUT) | (1 << NF_IP6_POST_ROUTING))) { |
| printk("ip6t_owner: only valid for LOCAL_OUT or POST_ROUTING.\n"); |
| return 0; |
| } |
| |
| if (matchsize != IP6T_ALIGN(sizeof(struct ip6t_owner_info))) |
| return 0; |
| #ifdef CONFIG_SMP |
| /* files->file_lock can not be used in a BH */ |
| if (((struct ip6t_owner_info *)matchinfo)->match |
| & (IP6T_OWNER_PID|IP6T_OWNER_SID)) { |
| printk("ip6t_owner: pid and sid matching is broken on SMP.\n"); |
| return 0; |
| } |
| #endif |
| return 1; |
| } |
| |
| static struct ip6t_match owner_match = { |
| .name = "owner", |
| .match = &match, |
| .checkentry = &checkentry, |
| .me = THIS_MODULE, |
| }; |
| |
| static int __init init(void) |
| { |
| return ip6t_register_match(&owner_match); |
| } |
| |
| static void __exit fini(void) |
| { |
| ip6t_unregister_match(&owner_match); |
| } |
| |
| module_init(init); |
| module_exit(fini); |