2002-09-20 11:29:01

by Olaf Dietsche

[permalink] [raw]
Subject: [ANNOUNCE][PATCH] accessfs v0.4 - 2.5.34

Hi,

Accessfs is a new file system to control access to system resources.
Currently it controls access to inet_bind() with ports < 1024 only.

With this patch, there's no need anymore to run internet daemons as
root. You can individually configure which user/program can bind to
ports below 1024.

For further information see the help text.

I adapted accessfs to linux 2.5.34.

The patch is attached below. It is also available at:
<http://home.t-online.de/home/olaf.dietsche/linux/accessfs-2.5.34-0.4.patch.gz>

I did minimal testing using uml 0.58-2.5.34.

Regards, Olaf.

diff -urN v2.5.34/fs/Config.in v2.5.34-accessfs/fs/Config.in
--- v2.5.34/fs/Config.in Sun Sep 1 00:05:30 2002
+++ v2.5.34-accessfs/fs/Config.in Thu Sep 19 21:45:49 2002
@@ -101,6 +101,9 @@
tristate 'UFS file system support (read only)' CONFIG_UFS_FS
dep_mbool ' UFS file system write support (DANGEROUS)' CONFIG_UFS_FS_WRITE $CONFIG_UFS_FS $CONFIG_EXPERIMENTAL

+dep_bool 'Accessfs support (EXPERIMENTAL)' CONFIG_ACCESS_FS $CONFIG_EXPERIMENTAL
+source fs/accessfs/Config.in
+
if [ "$CONFIG_NET" = "y" ]; then

mainmenu_option next_comment
diff -urN v2.5.34/fs/Makefile v2.5.34-accessfs/fs/Makefile
--- v2.5.34/fs/Makefile Sun Sep 1 00:05:27 2002
+++ v2.5.34-accessfs/fs/Makefile Thu Sep 19 21:45:49 2002
@@ -83,5 +83,6 @@
obj-$(CONFIG_REISERFS_FS) += reiserfs/
obj-$(CONFIG_SUN_OPENPROMFS) += openpromfs/
obj-$(CONFIG_JFS_FS) += jfs/
+obj-$(CONFIG_ACCESS_FS) += accessfs/

include $(TOPDIR)/Rules.make
diff -urN v2.5.34/fs/accessfs/Config.help v2.5.34-accessfs/fs/accessfs/Config.help
--- v2.5.34/fs/accessfs/Config.help Thu Jan 1 01:00:00 1970
+++ v2.5.34-accessfs/fs/accessfs/Config.help Thu Sep 19 21:45:49 2002
@@ -0,0 +1,53 @@
+Accessfs support (EXPERIMENTAL)
+CONFIG_ACCESS_FS
+ This is a new file system to control access to system resources.
+ Currently it controls access to bind() for IPv4 and IPv6.
+
+ With this file system, there's no need anymore to run internet daemons
+ as root. You can individually configure which user/program can bind to
+ protected ports (by default, below 1024).
+
+ For example, you can say, user www is allowed to bind to port 80 or
+ user mail is allowed to bind to port 25. Then, you can run apache as
+ user www and sendmail as user mail. Now, you don't have to rely on
+ apache or sendmail giving up superuser rights to enhance security.
+
+ To use this file system, you need to mount the file system
+ and do a chown on the appropriate ports:
+
+ # mount -t accessfs none /proc/access
+ # chown www /proc/access/net/ipv4/bind/80
+ # chown www /proc/access/net/ipv6/bind/80
+ # chown mail /proc/access/net/ipv4/bind/25
+ # chown mail /proc/access/net/ipv6/bind/25
+
+ You can grant access to a group for individual ports as well. Just say:
+
+ # chgrp lp /proc/access/net/ipv4/bind/515
+ # chown g+x /proc/access/net/ipv4/bind/515
+
+ The recommended mount point for this file-system is /proc/access,
+ which will appear automatically in the /proc filesystem.
+
+ If you're unsure, say N.
+
+Keep capabilities
+CONFIG_ACCESSFS_KEEP_CAPABILITIES
+ This option lets you choose, wether you want accessfs alone (N)
+ or in addition to capabilities (Y).
+ If you say N to this option, you may break applications and
+ configurations, which use capabilities already (e.g. BIND v9).
+
+ If you're unsure, say Y.
+
+Range of protected ports
+CONFIG_ACCESSFS_PROT_SOCK
+ Here you can extend the range of protected ports. This is
+ from 1-1023 inclusive on normal unix systems. One use for this
+ could be to reserve ports for X11 (port 6000) or database
+ servers (port 3306 for mysql), so nobody else could grab this
+ port.
+ The default permission for extended ports is --x--x--x.
+
+ If you're unsure, say 1024.
+
diff -urN v2.5.34/fs/accessfs/Config.in v2.5.34-accessfs/fs/accessfs/Config.in
--- v2.5.34/fs/accessfs/Config.in Thu Jan 1 01:00:00 1970
+++ v2.5.34-accessfs/fs/accessfs/Config.in Thu Sep 19 21:45:49 2002
@@ -0,0 +1,8 @@
+#
+# Accessfs configuration
+#
+dep_bool ' Keep capabilities' CONFIG_ACCESSFS_KEEP_CAPABILITIES $CONFIG_ACCESS_FS
+
+if [ "$CONFIG_ACCESS_FS" != "n" ]; then
+ int ' Range of protected ports (1024-65536)' CONFIG_ACCESSFS_PROT_SOCK 1024
+fi
diff -urN v2.5.34/fs/accessfs/Makefile v2.5.34-accessfs/fs/accessfs/Makefile
--- v2.5.34/fs/accessfs/Makefile Thu Jan 1 01:00:00 1970
+++ v2.5.34-accessfs/fs/accessfs/Makefile Thu Sep 19 21:57:58 2002
@@ -0,0 +1,9 @@
+#
+# Makefile for the linux accessfs routines.
+#
+
+obj-$(CONFIG_ACCESS_FS) += accessfs.o
+accessfs-objs := inode.o
+export-objs := inode.o
+
+include $(TOPDIR)/Rules.make
diff -urN v2.5.34/fs/accessfs/inode.c v2.5.34-accessfs/fs/accessfs/inode.c
--- v2.5.34/fs/accessfs/inode.c Thu Jan 1 01:00:00 1970
+++ v2.5.34-accessfs/fs/accessfs/inode.c Fri Sep 20 12:18:53 2002
@@ -0,0 +1,391 @@
+/* Copyright (c) 2001 Olaf Dietsche
+ *
+ * Access permission filesystem for Linux.
+ *
+ * 2002 Ben Clifford, create mount point at /proc/access
+ * 2002 Ben Clifford, trying to make it work under 2.5.5-dj2
+ * (see comments: BENC255 for reminders and todos)
+ *
+ *
+ * BENC255: the kernel doesn't lock BKL for us when entering methods
+ * (see Documentation/fs/porting.txt)
+ * Need to look at code here and see if we need either the BKL
+ * or our own lock - I think probably not.
+ *
+ */
+
+#include <linux/accessfs_fs.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+
+#include <asm/uaccess.h>
+
+typedef struct accessfs_entry afs_entry_t;
+typedef struct accessfs_direntry afs_dir_t;
+
+#define ACCESSFS_MAGIC 0x3c1d36e7
+
+#ifdef CONFIG_PROC_FS
+static struct proc_dir_entry *mountdir = NULL;
+#endif
+
+
+static struct inode_operations accessfs_inode_operations;
+static struct file_operations accessfs_dir_file_operations;
+static struct inode_operations accessfs_dir_inode_operations;
+
+static int accessfs_statfs(struct super_block *sb, struct statfs *buf)
+{
+ buf->f_type = ACCESSFS_MAGIC;
+ buf->f_bsize = PAGE_CACHE_SIZE;
+ buf->f_namelen = 255;
+ return 0;
+}
+
+static int accessfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+ int i;
+ struct dentry *dentry = filp->f_dentry;
+
+ i = filp->f_pos;
+ switch (i) {
+ case 0:
+ if (filldir(dirent, ".", 1, i, dentry->d_inode->i_ino, DT_DIR) < 0)
+ break;
+
+ ++i;
+ ++filp->f_pos;
+ /* NO break; */
+ case 1:
+ if (filldir(dirent, "..", 2, i, dentry->d_parent->d_inode->i_ino, DT_DIR) < 0)
+ break;
+
+ ++i;
+ ++filp->f_pos;
+ /* NO break; */
+ default: {
+ afs_dir_t *de = (afs_dir_t *) dentry->d_inode->u.generic_ip;
+ struct list_head *list;
+ int j;
+
+ list = de->children.next;
+
+ for (j = 2; j < i && list != &de->children; ++j)
+ list = list->next;
+
+ while (list != &de->children) {
+ afs_entry_t *pe = list_entry(list, afs_entry_t, siblings);
+ if (filldir(dirent, pe->name, strlen(pe->name), filp->f_pos, pe->ino, DT_UNKNOWN) < 0)
+ break;
+
+ ++filp->f_pos;
+ list = list->next;
+ }
+ }
+
+ break;
+ }
+
+ return 0;
+}
+
+static afs_entry_t *accessfs_lookup_entry(afs_entry_t *pe, const char *name, int len)
+{
+ if (S_ISDIR(pe->attr->mode)) {
+ struct list_head *list;
+ afs_dir_t *dir = (afs_dir_t *) pe;
+ list_for_each(list, &dir->children) {
+ afs_entry_t *de = list_entry(list, afs_entry_t, siblings);
+ if (strncmp(de->name, name, len) == 0 && de->name[len] == 0)
+ return de;
+ }
+ }
+
+ return NULL;
+}
+
+static struct dentry *accessfs_lookup(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = NULL;
+ afs_entry_t *pe;
+ pe = accessfs_lookup_entry(dir->u.generic_ip, dentry->d_name.name, dentry->d_name.len);
+ if (pe)
+ inode = iget(dir->i_sb, pe->ino);
+
+ d_add(dentry, inode);
+ return NULL;
+}
+
+static afs_dir_t accessfs_rootdir = {
+ { "/",
+ LIST_HEAD_INIT(accessfs_rootdir.node.hash),
+ LIST_HEAD_INIT(accessfs_rootdir.node.siblings),
+ 1, &accessfs_rootdir.attr },
+ NULL, LIST_HEAD_INIT(accessfs_rootdir.children),
+ { 0, 0, S_IFDIR | 0755 }
+};
+
+static void accessfs_init_inode(struct inode *inode, afs_entry_t *pe)
+{
+ inode->u.generic_ip = pe;
+ inode->i_uid = pe->attr->uid;
+ inode->i_gid = pe->attr->gid;
+ inode->i_mode = pe->attr->mode;
+/*
+ inode->i_blksize = PAGE_CACHE_SIZE;
+ inode->i_blocks = 0;
+ inode->i_rdev = NODEV;
+*/
+ inode->i_atime = inode->i_mtime = inode->i_ctime = 0;
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFREG:
+ inode->i_op = &accessfs_inode_operations;
+ break;
+ case S_IFDIR:
+ inode->i_op = &accessfs_dir_inode_operations;
+ inode->i_fop = &accessfs_dir_file_operations;
+ break;
+ default:
+ printk(KERN_ERR "accessfs_init_inode(): '%s' unhandled mode=%d\n", pe->name, inode->i_mode);
+ BUG();
+ break;
+ }
+}
+
+static struct inode *accessfs_get_root_inode(struct super_block *sb)
+{
+ struct inode *inode = new_inode(sb);
+ if (inode) {
+/* inode->i_ino = accessfs_rootdir.node.ino; */
+ accessfs_init_inode(inode, &accessfs_rootdir.node);
+ accessfs_rootdir.node.ino = inode->i_ino;
+ }
+
+ return inode;
+}
+
+static LIST_HEAD(hash);
+
+static int accessfs_node_init(afs_dir_t *parent, afs_entry_t *de, const char *name, size_t len, struct access_attr *attr, mode_t mode)
+{
+ static unsigned long ino = 1;
+ de->name = kmalloc(len + 1, GFP_KERNEL);
+ if (de->name == NULL)
+ return -ENOMEM;
+
+ strncpy(de->name, name, len);
+ de->name[len] = 0;
+ de->ino = ++ino;
+ de->attr = attr;
+ de->attr->uid = 0;
+ de->attr->gid = 0;
+ de->attr->mode = mode;
+ list_add_tail(&de->hash, &hash);
+ list_add_tail(&de->siblings, &parent->children);
+ return 0;
+}
+
+static int accessfs_mknod(afs_dir_t *dir, const char *name, struct access_attr *attr)
+{
+ afs_entry_t *pe = kmalloc(sizeof(afs_entry_t), GFP_KERNEL);
+ if (pe == NULL)
+ return -ENOMEM;
+
+ accessfs_node_init(dir, pe, name, strlen(name), attr, S_IFREG | attr->mode);
+ return 0;
+}
+
+static afs_dir_t *accessfs_mkdir(afs_dir_t *parent, const char *name, size_t len)
+{
+ int error;
+ afs_dir_t *dir = kmalloc(sizeof(afs_dir_t), GFP_KERNEL);
+ if (dir == NULL)
+ return NULL;
+
+ error = accessfs_node_init(parent, &dir->node, name, len, &dir->attr, S_IFDIR | 0755);
+ if (error) {
+ kfree(dir);
+ return NULL;
+ }
+
+ dir->parent = parent;
+ INIT_LIST_HEAD(&dir->children);
+ return dir;
+}
+
+afs_dir_t *accessfs_make_dirpath(const char *name)
+{
+ afs_dir_t *dir = &accessfs_rootdir;
+ const char *slash;
+ do {
+ afs_entry_t *de;
+ size_t len;
+ while (*name == '/')
+ ++name;
+
+ slash = strchr(name, '/');
+ len = slash ? slash - name : strlen(name);
+ de = accessfs_lookup_entry(&dir->node, name, len);
+ if (de == NULL) {
+ dir = accessfs_mkdir(dir, name, len);
+ } else if (S_ISDIR(de->attr->mode)) {
+ dir = (afs_dir_t *) de;
+ } else {
+ return NULL;
+ }
+
+ if (dir == NULL)
+ return NULL;
+
+ name = slash + 1;
+ } while (slash != NULL);
+
+ return dir;
+}
+
+static void accessfs_unlink(afs_entry_t *pe)
+{
+ list_del(&pe->hash);
+ list_del(&pe->siblings);
+ kfree(pe->name);
+ kfree(pe);
+}
+
+static int accessfs_notify_change(struct dentry *dentry, struct iattr *iattr)
+{
+ struct inode *i = dentry->d_inode;
+ int error = inode_setattr(i, iattr);
+ if (!error) {
+ afs_entry_t *pe = (afs_entry_t *) i->u.generic_ip;
+ pe->attr->uid = i->i_uid;
+ pe->attr->gid = i->i_gid;
+ pe->attr->mode = i->i_mode;
+ }
+
+ return error;
+}
+
+static void accessfs_read_inode(struct inode *inode)
+{
+ ino_t ino = inode->i_ino;
+ struct list_head *list;
+ list_for_each(list, &hash) {
+ afs_entry_t *pe = list_entry(list, afs_entry_t, hash);
+ if (pe->ino == ino) {
+ accessfs_init_inode(inode, pe);
+ return;
+ }
+ }
+}
+
+static struct inode_operations accessfs_inode_operations = {
+ setattr: accessfs_notify_change,
+};
+
+static struct inode_operations accessfs_dir_inode_operations = {
+ lookup: accessfs_lookup,
+ setattr: accessfs_notify_change,
+};
+
+static struct file_operations accessfs_dir_file_operations = {
+ readdir: accessfs_readdir,
+};
+
+static struct super_operations accessfs_ops = {
+ read_inode: accessfs_read_inode,
+ statfs: accessfs_statfs,
+};
+
+static int accessfs_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct inode *inode;
+ struct dentry *root;
+
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = ACCESSFS_MAGIC;
+ sb->s_op = &accessfs_ops;
+ inode = accessfs_get_root_inode(sb);
+ if (!inode)
+ return -ENOMEM;
+
+ root = d_alloc_root(inode);
+ if (!root) {
+ iput(inode);
+ return -ENOMEM;
+ }
+
+ sb->s_root = root;
+ return 0;
+}
+
+static struct super_block *accessfs_get_sb(struct file_system_type *fs_type, int flags, char *dev_name, void *data)
+{
+ return get_sb_single(fs_type, flags, data, accessfs_fill_super);
+}
+
+int accessfs_permitted(struct access_attr *p, int mask)
+{
+ mode_t mode = p->mode;
+ if (current->fsuid == p->uid)
+ mode >>= 6;
+ else if (in_group_p(p->gid))
+ mode >>= 3;
+
+ return (mode & mask) == mask;
+}
+
+void accessfs_register(afs_dir_t *dir, const char *name, struct access_attr *attr)
+{
+ if (dir) {
+ accessfs_mknod(dir, name, attr);
+ }
+}
+
+void accessfs_unregister(afs_dir_t *dir, const char *name)
+{
+ afs_entry_t *pe = accessfs_lookup_entry(&dir->node, name, strlen(name));
+ if (pe) {
+ accessfs_unlink(pe);
+ }
+}
+
+static struct file_system_type accessfs_fs_type = {
+ name: "accessfs",
+ get_sb: accessfs_get_sb,
+/* kill_sb: kill_litter_super, */
+ kill_sb: kill_anon_super,
+};
+
+static int __init init_accessfs_fs(void)
+{
+
+#ifdef CONFIG_PROC_FS
+ /* create mount point for accessfs */
+ mountdir = proc_mkdir("access",&proc_root);
+#endif
+
+ return register_filesystem(&accessfs_fs_type);
+}
+
+static void __exit exit_accessfs_fs(void)
+{
+ unregister_filesystem(&accessfs_fs_type);
+
+#ifdef CONFIG_PROC_FS
+ remove_proc_entry("access",&proc_root);
+#endif
+}
+
+module_init(init_accessfs_fs)
+module_exit(exit_accessfs_fs)
+
+EXPORT_SYMBOL(accessfs_permitted);
+EXPORT_SYMBOL(accessfs_make_dirpath);
+EXPORT_SYMBOL(accessfs_register);
+EXPORT_SYMBOL(accessfs_unregister);
diff -urN v2.5.34/include/linux/accessfs_fs.h v2.5.34-accessfs/include/linux/accessfs_fs.h
--- v2.5.34/include/linux/accessfs_fs.h Thu Jan 1 01:00:00 1970
+++ v2.5.34-accessfs/include/linux/accessfs_fs.h Thu Sep 19 21:45:49 2002
@@ -0,0 +1,52 @@
+/* -*- mode: c -*- */
+#ifndef __accessfs_fs_h_included__
+#define __accessfs_fs_h_included__ 1
+
+/* Copyright (c) 2001 Olaf Dietsche
+ *
+ * $Log$
+ */
+
+#include <linux/config.h>
+#include <linux/fs.h>
+#include <net/sock.h>
+
+struct access_attr {
+ uid_t uid;
+ gid_t gid;
+ mode_t mode;
+};
+
+struct accessfs_entry {
+ char *name;
+ struct list_head hash;
+ struct list_head siblings;
+ ino_t ino;
+ struct access_attr *attr;
+};
+
+struct accessfs_direntry {
+ struct accessfs_entry node;
+ struct accessfs_direntry *parent;
+ struct list_head children;
+ struct access_attr attr;
+};
+
+extern int accessfs_permitted(struct access_attr *p, int mask);
+extern struct accessfs_direntry *accessfs_make_dirpath(const char *name);
+extern void accessfs_register(struct accessfs_direntry *dir, const char *name, struct access_attr *attr);
+extern void accessfs_unregister(struct accessfs_direntry *dir, const char *name);
+
+#ifdef CONFIG_ACCESSFS_KEEP_CAPABILITIES
+#define accessfs_capable(x) capable(x)
+#else
+#define accessfs_capable(x) 0
+#endif
+
+#if CONFIG_ACCESSFS_PROT_SOCK < PROT_SOCK
+#define CONFIG_ACCESSFS_PROT_SOCK PROT_SOCK
+#elseif CONFIG_ACCESSFS_PROT_SOCK > 65536
+#define CONFIG_ACCESSFS_PROT_SOCK 65536
+#endif
+
+#endif
diff -urN v2.5.34/net/ipv4/af_inet.c v2.5.34-accessfs/net/ipv4/af_inet.c
--- v2.5.34/net/ipv4/af_inet.c Sun Sep 1 00:04:50 2002
+++ v2.5.34-accessfs/net/ipv4/af_inet.c Thu Sep 19 21:45:49 2002
@@ -120,6 +120,9 @@
#if defined(CONFIG_NET_RADIO) || defined(CONFIG_NET_PCMCIA_RADIO)
#include <linux/wireless.h> /* Note : will define WIRELESS_EXT */
#endif /* CONFIG_NET_RADIO || CONFIG_NET_PCMCIA_RADIO */
+#ifdef CONFIG_ACCESS_FS
+#include <linux/accessfs_fs.h>
+#endif

struct linux_mib net_statistics[NR_CPUS * 2];

@@ -349,6 +352,14 @@
* Create an inet socket.
*/

+#ifdef CONFIG_ACCESS_FS
+static struct access_attr raw_socket = {
+ uid: 0,
+ gid: 0,
+ mode: S_IXUSR,
+};
+#endif
+
static int inet_create(struct socket *sock, int protocol)
{
struct sock *sk;
@@ -390,7 +401,11 @@
if (!answer)
goto out_sk_free;
err = -EPERM;
+#ifdef CONFIG_ACCESS_FS
+ if (answer->capability > 0 && !(answer->capability == CAP_NET_RAW && accessfs_permitted(&raw_socket, MAY_EXEC)) && !accessfs_capable(answer->capability))
+#else
if (answer->capability > 0 && !capable(answer->capability))
+#endif
goto out_sk_free;
err = -EPROTONOSUPPORT;
if (!protocol)
@@ -490,6 +505,10 @@
return 0;
}

+#ifdef CONFIG_ACCESS_FS
+static struct access_attr bind_to_port[CONFIG_ACCESSFS_PROT_SOCK];
+#endif
+
/* It is off by default, see below. */
int sysctl_ip_nonlocal_bind;

@@ -531,7 +550,11 @@

snum = ntohs(addr->sin_port);
err = -EACCES;
+#ifdef CONFIG_ACCESS_FS
+ if (snum && snum < CONFIG_ACCESSFS_PROT_SOCK && !accessfs_permitted(&bind_to_port[snum], MAY_EXEC) && !accessfs_capable(CAP_NET_BIND_SERVICE))
+#else
if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
+#endif
goto out;

/* We keep a pair of addresses. rcv_saddr is the one
@@ -1121,6 +1144,29 @@
}
}

+#ifdef CONFIG_ACCESS_FS
+static void accessfs_init(void)
+{
+ struct accessfs_direntry *dir = accessfs_make_dirpath("net/ipv4/bind");
+ int i;
+ for (i = 1; i < CONFIG_ACCESSFS_PROT_SOCK; ++i) {
+ char buf[sizeof("65536")];
+ bind_to_port[i].uid = 0;
+ bind_to_port[i].gid = 0;
+ bind_to_port[i].mode = i < PROT_SOCK ? S_IXUSR : S_IXUGO;
+ sprintf(buf, "%d", i);
+ accessfs_register(dir, buf, &bind_to_port[i]);
+ }
+
+ dir = accessfs_make_dirpath("net/ipv4");
+#if 0
+ raw_socket.uid = 0;
+ raw_socket.gid = 0;
+ raw_socket.mode = S_IXUSR;
+#endif
+ accessfs_register(dir, "raw", &raw_socket);
+}
+#endif

/*
* Called by socket.c on kernel startup.
@@ -1229,6 +1275,11 @@
proc_net_create ("tcp", 0, tcp_get_info);
proc_net_create ("udp", 0, udp_get_info);
#endif /* CONFIG_PROC_FS */
+
+#ifdef CONFIG_ACCESS_FS
+ accessfs_init();
+#endif
+
return 0;
}
module_init(inet_init);
diff -urN v2.5.34/net/ipv6/af_inet6.c v2.5.34-accessfs/net/ipv6/af_inet6.c
--- v2.5.34/net/ipv6/af_inet6.c Sun Sep 1 00:05:27 2002
+++ v2.5.34-accessfs/net/ipv6/af_inet6.c Thu Sep 19 21:45:49 2002
@@ -47,6 +47,9 @@
#include <linux/icmpv6.h>
#include <linux/brlock.h>
#include <linux/smp_lock.h>
+#ifdef CONFIG_ACCESS_FS
+#include <linux/accessfs_fs.h>
+#endif

#include <net/ip.h>
#include <net/ipv6.h>
@@ -272,6 +275,9 @@
return -ENOBUFS;
}

+#ifdef CONFIG_ACCESS_FS
+static struct access_attr bind_to_port[CONFIG_ACCESSFS_PROT_SOCK];
+#endif

/* bind for INET6 API */
int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
@@ -313,7 +319,11 @@
}

snum = ntohs(addr->sin6_port);
+#ifdef CONFIG_ACCESS_FS
+ if (snum && snum < CONFIG_ACCESSFS_PROT_SOCK && !accessfs_permitted(&bind_to_port[snum], MAY_EXEC) && !accessfs_capable(CAP_NET_BIND_SERVICE))
+#else
if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
+#endif
return -EACCES;

lock_sock(sk);
@@ -632,6 +642,35 @@
inet_unregister_protosw(p);
}

+#ifdef CONFIG_ACCESS_FS
+static void accessfs_init(void)
+{
+ struct accessfs_direntry *dir = accessfs_make_dirpath("net/ipv6/bind");
+ int i;
+ for (i = 1; i < CONFIG_ACCESSFS_PROT_SOCK; ++i) {
+ char buf[sizeof("65536")];
+ bind_to_port[i].uid = 0;
+ bind_to_port[i].gid = 0;
+ bind_to_port[i].mode = i < PROT_SOCK ? S_IXUSR : S_IXUGO;
+ sprintf(buf, "%d", i);
+ accessfs_register(dir, buf, &bind_to_port[i]);
+ }
+}
+
+#ifdef MODULE
+static void accessfs_exit(void)
+{
+ struct accessfs_direntry *dir = accessfs_make_dirpath("net/ipv6/bind");
+ int i;
+ for (i = 1; i < CONFIG_ACCESSFS_PROT_SOCK; ++i) {
+ char buf[sizeof("65536")];
+ sprintf(buf, "%d", i);
+ accessfs_unregister(dir, buf);
+ }
+}
+#endif
+#endif
+
static int __init inet6_init(void)
{
struct sk_buff *dummy_skb;
@@ -679,6 +718,10 @@
* be able to create sockets. (?? is this dangerous ??)
*/
(void) sock_register(&inet6_family_ops);
+
+#ifdef CONFIG_ACCESS_FS
+ accessfs_init();
+#endif

/*
* ipngwg API draft makes clear that the correct semantics
@@ -775,6 +818,9 @@
icmpv6_cleanup();
#ifdef CONFIG_SYSCTL
ipv6_sysctl_unregister();
+#endif
+#ifdef CONFIG_ACCESS_FS
+ accessfs_exit();
#endif
}
module_exit(inet6_exit);