system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-11-05 18:23:50 +00:00
Code Issues Projects Releases Packages Wiki Activity
linux/net/ipv4/ping.c
Linus Torvalds 644473e9c6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 
Pull user namespace enhancements from Eric Biederman:
 "This is a course correction for the user namespace, so that we can
  reach an inexpensive, maintainable, and reasonably complete
  implementation.

  Highlights:
   - Config guards make it impossible to enable the user namespace and
     code that has not been converted to be user namespace safe.

   - Use of the new kuid_t type ensures the if you somehow get past the
     config guards the kernel will encounter type errors if you enable
     user namespaces and attempt to compile in code whose permission
     checks have not been updated to be user namespace safe.

   - All uids from child user namespaces are mapped into the initial
     user namespace before they are processed.  Removing the need to add
     an additional check to see if the user namespace of the compared
     uids remains the same.

   - With the user namespaces compiled out the performance is as good or
     better than it is today.

   - For most operations absolutely nothing changes performance or
     operationally with the user namespace enabled.

   - The worst case performance I could come up with was timing 1
     billion cache cold stat operations with the user namespace code
     enabled.  This went from 156s to 164s on my laptop (or 156ns to
     164ns per stat operation).

   - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value.
     Most uid/gid setting system calls treat these value specially
     anyway so attempting to use -1 as a uid would likely cause
     entertaining failures in userspace.

   - If setuid is called with a uid that can not be mapped setuid fails.
     I have looked at sendmail, login, ssh and every other program I
     could think of that would call setuid and they all check for and
     handle the case where setuid fails.

   - If stat or a similar system call is called from a context in which
     we can not map a uid we lie and return overflowuid.  The LFS
     experience suggests not lying and returning an error code might be
     better, but the historical precedent with uids is different and I
     can not think of anything that would break by lying about a uid we
     can't map.

   - Capabilities are localized to the current user namespace making it
     safe to give the initial user in a user namespace all capabilities.

  My git tree covers all of the modifications needed to convert the core
  kernel and enough changes to make a system bootable to runlevel 1."

Fix up trivial conflicts due to nearby independent changes in fs/stat.c

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
  userns:  Silence silly gcc warning.
  cred: use correct cred accessor with regards to rcu read lock
  userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq
  userns: Convert cgroup permission checks to use uid_eq
  userns: Convert tmpfs to use kuid and kgid where appropriate
  userns: Convert sysfs to use kgid/kuid where appropriate
  userns: Convert sysctl permission checks to use kuid and kgids.
  userns: Convert proc to use kuid/kgid where appropriate
  userns: Convert ext4 to user kuid/kgid where appropriate
  userns: Convert ext3 to use kuid/kgid where appropriate
  userns: Convert ext2 to use kuid/kgid where appropriate.
  userns: Convert devpts to use kuid/kgid where appropriate
  userns: Convert binary formats to use kuid/kgid where appropriate
  userns: Add negative depends on entries to avoid building code that is userns unsafe
  userns: signal remove unnecessary map_cred_ns
  userns: Teach inode_capable to understand inodes whose uids map to other namespaces.
  userns: Fail exec for suid and sgid binaries with ids outside our user namespace.
  userns: Convert stat to return values mapped from kuids and kgids
  userns: Convert user specfied uids and gids in chown into kuids and kgid
  userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
  ...
2012-05-23 17:42:39 -07:00

939 lines
21 KiB
C
Raw Blame History

/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* "Ping" sockets
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Based on ipv4/udp.c code.
*
* Authors: Vasiliy Kulikov / Openwall (for Linux 2.6),
* Pavel Kankovsky (for Linux 2.4.32)
*
* Pavel gave all rights to bugs to Vasiliy,
* none of the bugs are Pavel's now.
*
*/
#include <linux/uaccess.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/snmp.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/icmp.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/export.h>
#include <net/sock.h>
#include <net/ping.h>
#include <net/udp.h>
#include <net/route.h>
#include <net/inet_common.h>
#include <net/checksum.h>
static struct ping_table ping_table;
static u16 ping_port_rover;
static inline int ping_hashfn(struct net *net, unsigned int num, unsigned int mask)
{
int res = (num + net_hash_mix(net)) & mask;
pr_debug("hash(%d) = %d\n", num, res);
return res;
}
static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
struct net *net, unsigned int num)
{
return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
}
static int ping_v4_get_port(struct sock *sk, unsigned short ident)
{
struct hlist_nulls_node *node;
struct hlist_nulls_head *hlist;
struct inet_sock *isk, *isk2;
struct sock *sk2 = NULL;
isk = inet_sk(sk);
write_lock_bh(&ping_table.lock);
if (ident == 0) {
u32 i;
u16 result = ping_port_rover + 1;
for (i = 0; i < (1L << 16); i++, result++) {
if (!result)
result++; /* avoid zero */
hlist = ping_hashslot(&ping_table, sock_net(sk),
result);
ping_portaddr_for_each_entry(sk2, node, hlist) {
isk2 = inet_sk(sk2);
if (isk2->inet_num == result)
goto next_port;
}
/* found */
ping_port_rover = ident = result;
break;
next_port:
;
}
if (i >= (1L << 16))
goto fail;
} else {
hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
ping_portaddr_for_each_entry(sk2, node, hlist) {
isk2 = inet_sk(sk2);
if ((isk2->inet_num == ident) &&
(sk2 != sk) &&
(!sk2->sk_reuse || !sk->sk_reuse))
goto fail;
}
}
pr_debug("found port/ident = %d\n", ident);
isk->inet_num = ident;
if (sk_unhashed(sk)) {
pr_debug("was not hashed\n");
sock_hold(sk);
hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
}
write_unlock_bh(&ping_table.lock);
return 0;
fail:
write_unlock_bh(&ping_table.lock);
return 1;
}
static void ping_v4_hash(struct sock *sk)
{
pr_debug("ping_v4_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
BUG(); /* "Please do not press this button again." */
}
static void ping_v4_unhash(struct sock *sk)
{
struct inet_sock *isk = inet_sk(sk);
pr_debug("ping_v4_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
if (sk_hashed(sk)) {
write_lock_bh(&ping_table.lock);
hlist_nulls_del(&sk->sk_nulls_node);
sock_put(sk);
isk->inet_num = 0;
isk->inet_sport = 0;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
write_unlock_bh(&ping_table.lock);
}
}
static struct sock *ping_v4_lookup(struct net *net, __be32 saddr, __be32 daddr,
u16 ident, int dif)
{
struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
struct sock *sk = NULL;
struct inet_sock *isk;
struct hlist_nulls_node *hnode;
pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
(int)ident, &daddr, dif);
read_lock_bh(&ping_table.lock);
ping_portaddr_for_each_entry(sk, hnode, hslot) {
isk = inet_sk(sk);
pr_debug("found: %p: num = %d, daddr = %pI4, dif = %d\n", sk,
(int)isk->inet_num, &isk->inet_rcv_saddr,
sk->sk_bound_dev_if);
pr_debug("iterate\n");
if (isk->inet_num != ident)
continue;
if (isk->inet_rcv_saddr && isk->inet_rcv_saddr != daddr)
continue;
if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
continue;
sock_hold(sk);
goto exit;
}
sk = NULL;
exit:
read_unlock_bh(&ping_table.lock);
return sk;
}
static void inet_get_ping_group_range_net(struct net *net, gid_t *low,
gid_t *high)
{
gid_t *data = net->ipv4.sysctl_ping_group_range;
unsigned int seq;
do {
seq = read_seqbegin(&sysctl_local_ports.lock);
*low = data[0];
*high = data[1];
} while (read_seqretry(&sysctl_local_ports.lock, seq));
}
static int ping_init_sock(struct sock *sk)
{
struct net *net = sock_net(sk);
gid_t group = current_egid();
gid_t range[2];
struct group_info *group_info = get_current_groups();
int i, j, count = group_info->ngroups;
kgid_t low, high;
inet_get_ping_group_range_net(net, range, range+1);
low = make_kgid(&init_user_ns, range[0]);
high = make_kgid(&init_user_ns, range[1]);
if (!gid_valid(low) || !gid_valid(high) || gid_lt(high, low))
return -EACCES;
if (range[0] <= group && group <= range[1])
return 0;
for (i = 0; i < group_info->nblocks; i++) {
int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
for (j = 0; j < cp_count; j++) {
kgid_t gid = group_info->blocks[i][j];
if (gid_lte(low, gid) && gid_lte(gid, high))
return 0;
}
count -= cp_count;
}
return -EACCES;
}
static void ping_close(struct sock *sk, long timeout)
{
pr_debug("ping_close(sk=%p,sk->num=%u)\n",
inet_sk(sk), inet_sk(sk)->inet_num);
pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
sk_common_release(sk);
}
/*
* We need our own bind because there are no privileged id's == local ports.
* Moreover, we don't allow binding to multi- and broadcast addresses.
*/
static int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
struct inet_sock *isk = inet_sk(sk);
unsigned short snum;
int chk_addr_ret;
int err;
if (addr_len < sizeof(struct sockaddr_in))
return -EINVAL;
pr_debug("ping_v4_bind(sk=%p,sa_addr=%08x,sa_port=%d)\n",
sk, addr->sin_addr.s_addr, ntohs(addr->sin_port));
chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
chk_addr_ret = RTN_LOCAL;
if ((sysctl_ip_nonlocal_bind == 0 &&
isk->freebind == 0 && isk->transparent == 0 &&
chk_addr_ret != RTN_LOCAL) ||
chk_addr_ret == RTN_MULTICAST ||
chk_addr_ret == RTN_BROADCAST)
return -EADDRNOTAVAIL;
lock_sock(sk);
err = -EINVAL;
if (isk->inet_num != 0)
goto out;
err = -EADDRINUSE;
isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
snum = ntohs(addr->sin_port);
if (ping_v4_get_port(sk, snum) != 0) {
isk->inet_saddr = isk->inet_rcv_saddr = 0;
goto out;
}
pr_debug("after bind(): num = %d, daddr = %pI4, dif = %d\n",
(int)isk->inet_num,
&isk->inet_rcv_saddr,
(int)sk->sk_bound_dev_if);
err = 0;
if (isk->inet_rcv_saddr)
sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
if (snum)
sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
isk->inet_sport = htons(isk->inet_num);
isk->inet_daddr = 0;
isk->inet_dport = 0;
sk_dst_reset(sk);
out:
release_sock(sk);
pr_debug("ping_v4_bind -> %d\n", err);
return err;
}
/*
* Is this a supported type of ICMP message?
*/
static inline int ping_supported(int type, int code)
{
if (type == ICMP_ECHO && code == 0)
return 1;
return 0;
}
/*
* This routine is called by the ICMP module when it gets some
* sort of error condition.
*/
static int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
void ping_err(struct sk_buff *skb, u32 info)
{
struct iphdr *iph = (struct iphdr *)skb->data;
struct icmphdr *icmph = (struct icmphdr *)(skb->data+(iph->ihl<<2));
struct inet_sock *inet_sock;
int type = icmph->type;
int code = icmph->code;
struct net *net = dev_net(skb->dev);
struct sock *sk;
int harderr;
int err;
/* We assume the packet has already been checked by icmp_unreach */
if (!ping_supported(icmph->type, icmph->code))
return;
pr_debug("ping_err(type=%04x,code=%04x,id=%04x,seq=%04x)\n", type,
code, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
sk = ping_v4_lookup(net, iph->daddr, iph->saddr,
ntohs(icmph->un.echo.id), skb->dev->ifindex);
if (sk == NULL) {
pr_debug("no socket, dropping\n");
return; /* No socket for error */
}
pr_debug("err on socket %p\n", sk);
err = 0;
harderr = 0;
inet_sock = inet_sk(sk);
switch (type) {
default:
case ICMP_TIME_EXCEEDED:
err = EHOSTUNREACH;
break;
case ICMP_SOURCE_QUENCH:
/* This is not a real error but ping wants to see it.
* Report it with some fake errno. */
err = EREMOTEIO;
break;
case ICMP_PARAMETERPROB:
err = EPROTO;
harderr = 1;
break;
case ICMP_DEST_UNREACH:
if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
err = EMSGSIZE;
harderr = 1;
break;
}
goto out;
}
err = EHOSTUNREACH;
if (code <= NR_ICMP_UNREACH) {
harderr = icmp_err_convert[code].fatal;
err = icmp_err_convert[code].errno;
}
break;
case ICMP_REDIRECT:
/* See ICMP_SOURCE_QUENCH */
err = EREMOTEIO;
break;
}
/*
* RFC1122: OK. Passes ICMP errors back to application, as per
* 4.1.3.3.
*/
if (!inet_sock->recverr) {
if (!harderr || sk->sk_state != TCP_ESTABLISHED)
goto out;
} else {
ip_icmp_error(sk, skb, err, 0 /* no remote port */,
info, (u8 *)icmph);
}
sk->sk_err = err;
sk->sk_error_report(sk);
out:
sock_put(sk);
}
/*
* Copy and checksum an ICMP Echo packet from user space into a buffer.
*/
struct pingfakehdr {
struct icmphdr icmph;
struct iovec *iov;
__wsum wcheck;
};
static int ping_getfrag(void *from, char *to,
int offset, int fraglen, int odd, struct sk_buff *skb)
{
struct pingfakehdr *pfh = (struct pingfakehdr *)from;
if (offset == 0) {
if (fraglen < sizeof(struct icmphdr))
BUG();
if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
pfh->iov, 0, fraglen - sizeof(struct icmphdr),
&pfh->wcheck))
return -EFAULT;
return 0;
}
if (offset < sizeof(struct icmphdr))
BUG();
if (csum_partial_copy_fromiovecend
(to, pfh->iov, offset - sizeof(struct icmphdr),
fraglen, &pfh->wcheck))
return -EFAULT;
return 0;
}
static int ping_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
struct flowi4 *fl4)
{
struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
pfh->wcheck = csum_partial((char *)&pfh->icmph,
sizeof(struct icmphdr), pfh->wcheck);
pfh->icmph.checksum = csum_fold(pfh->wcheck);
memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
skb->ip_summed = CHECKSUM_NONE;
return ip_push_pending_frames(sk, fl4);
}
static int ping_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
size_t len)
{
struct net *net = sock_net(sk);
struct flowi4 fl4;
struct inet_sock *inet = inet_sk(sk);
struct ipcm_cookie ipc;
struct icmphdr user_icmph;
struct pingfakehdr pfh;
struct rtable *rt = NULL;
struct ip_options_data opt_copy;
int free = 0;
__be32 saddr, daddr, faddr;
u8 tos;
int err;
pr_debug("ping_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
if (len > 0xFFFF)
return -EMSGSIZE;
/*
* Check the flags.
*/
/* Mirror BSD error message compatibility */
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
/*
* Fetch the ICMP header provided by the userland.
* iovec is modified!
*/
if (memcpy_fromiovec((u8 *)&user_icmph, msg->msg_iov,
sizeof(struct icmphdr)))
return -EFAULT;
if (!ping_supported(user_icmph.type, user_icmph.code))
return -EINVAL;
/*
* Get and verify the address.
*/
if (msg->msg_name) {
struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
if (msg->msg_namelen < sizeof(*usin))
return -EINVAL;
if (usin->sin_family != AF_INET)
return -EINVAL;
daddr = usin->sin_addr.s_addr;
/* no remote port */
} else {
if (sk->sk_state != TCP_ESTABLISHED)
return -EDESTADDRREQ;
daddr = inet->inet_daddr;
/* no remote port */
}
ipc.addr = inet->inet_saddr;
ipc.opt = NULL;
ipc.oif = sk->sk_bound_dev_if;
ipc.tx_flags = 0;
err = sock_tx_timestamp(sk, &ipc.tx_flags);
if (err)
return err;
if (msg->msg_controllen) {
err = ip_cmsg_send(sock_net(sk), msg, &ipc);
if (err)
return err;
if (ipc.opt)
free = 1;
}
if (!ipc.opt) {
struct ip_options_rcu *inet_opt;
rcu_read_lock();
inet_opt = rcu_dereference(inet->inet_opt);
if (inet_opt) {
memcpy(&opt_copy, inet_opt,
sizeof(*inet_opt) + inet_opt->opt.optlen);
ipc.opt = &opt_copy.opt;
}
rcu_read_unlock();
}
saddr = ipc.addr;
ipc.addr = faddr = daddr;
if (ipc.opt && ipc.opt->opt.srr) {
if (!daddr)
return -EINVAL;
faddr = ipc.opt->opt.faddr;
}
tos = RT_TOS(inet->tos);
if (sock_flag(sk, SOCK_LOCALROUTE) ||
(msg->msg_flags & MSG_DONTROUTE) ||
(ipc.opt && ipc.opt->opt.is_strictroute)) {
tos |= RTO_ONLINK;
}
if (ipv4_is_multicast(daddr)) {
if (!ipc.oif)
ipc.oif = inet->mc_index;
if (!saddr)
saddr = inet->mc_addr;
} else if (!ipc.oif)
ipc.oif = inet->uc_index;
flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
RT_SCOPE_UNIVERSE, sk->sk_protocol,
inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
rt = ip_route_output_flow(net, &fl4, sk);
if (IS_ERR(rt)) {
err = PTR_ERR(rt);
rt = NULL;
if (err == -ENETUNREACH)
IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
goto out;
}
err = -EACCES;
if ((rt->rt_flags & RTCF_BROADCAST) &&
!sock_flag(sk, SOCK_BROADCAST))
goto out;
if (msg->msg_flags & MSG_CONFIRM)
goto do_confirm;
back_from_confirm:
if (!ipc.addr)
ipc.addr = fl4.daddr;
lock_sock(sk);
pfh.icmph.type = user_icmph.type; /* already checked */
pfh.icmph.code = user_icmph.code; /* ditto */
pfh.icmph.checksum = 0;
pfh.icmph.un.echo.id = inet->inet_sport;
pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
pfh.iov = msg->msg_iov;
pfh.wcheck = 0;
err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
0, &ipc, &rt, msg->msg_flags);
if (err)
ip_flush_pending_frames(sk);
else
err = ping_push_pending_frames(sk, &pfh, &fl4);
release_sock(sk);
out:
ip_rt_put(rt);
if (free)
kfree(ipc.opt);
if (!err) {
icmp_out_count(sock_net(sk), user_icmph.type);
return len;
}
return err;
do_confirm:
dst_confirm(&rt->dst);
if (!(msg->msg_flags & MSG_PROBE) || len)
goto back_from_confirm;
err = 0;
goto out;
}
static int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
size_t len, int noblock, int flags, int *addr_len)
{
struct inet_sock *isk = inet_sk(sk);
struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
struct sk_buff *skb;
int copied, err;
pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
err = -EOPNOTSUPP;
if (flags & MSG_OOB)
goto out;
if (addr_len)
*addr_len = sizeof(*sin);
if (flags & MSG_ERRQUEUE)
return ip_recv_error(sk, msg, len);
skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb)
goto out;
copied = skb->len;
if (copied > len) {
msg->msg_flags |= MSG_TRUNC;
copied = len;
}
/* Don't bother checking the checksum */
err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
if (err)
goto done;
sock_recv_timestamp(msg, sk, skb);
/* Copy the address. */
if (sin) {
sin->sin_family = AF_INET;
sin->sin_port = 0 /* skb->h.uh->source */;
sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
}
if (isk->cmsg_flags)
ip_cmsg_recv(msg, skb);
err = copied;
done:
skb_free_datagram(sk, skb);
out:
pr_debug("ping_recvmsg -> %d\n", err);
return err;
}
static int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
inet_sk(sk), inet_sk(sk)->inet_num, skb);
if (sock_queue_rcv_skb(sk, skb) < 0) {
kfree_skb(skb);
pr_debug("ping_queue_rcv_skb -> failed\n");
return -1;
}
return 0;
}
/*
* All we need to do is get the socket.
*/
void ping_rcv(struct sk_buff *skb)
{
struct sock *sk;
struct net *net = dev_net(skb->dev);
struct iphdr *iph = ip_hdr(skb);
struct icmphdr *icmph = icmp_hdr(skb);
__be32 saddr = iph->saddr;
__be32 daddr = iph->daddr;
/* We assume the packet has already been checked by icmp_rcv */
pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
/* Push ICMP header back */
skb_push(skb, skb->data - (u8 *)icmph);
sk = ping_v4_lookup(net, saddr, daddr, ntohs(icmph->un.echo.id),
skb->dev->ifindex);
if (sk != NULL) {
pr_debug("rcv on socket %p\n", sk);
ping_queue_rcv_skb(sk, skb_get(skb));
sock_put(sk);
return;
}
pr_debug("no socket, dropping\n");
/* We're called from icmp_rcv(). kfree_skb() is done there. */
}
struct proto ping_prot = {
.name = "PING",
.owner = THIS_MODULE,
.init = ping_init_sock,
.close = ping_close,
.connect = ip4_datagram_connect,
.disconnect = udp_disconnect,
.setsockopt = ip_setsockopt,
.getsockopt = ip_getsockopt,
.sendmsg = ping_sendmsg,
.recvmsg = ping_recvmsg,
.bind = ping_bind,
.backlog_rcv = ping_queue_rcv_skb,
.hash = ping_v4_hash,
.unhash = ping_v4_unhash,
.get_port = ping_v4_get_port,
.obj_size = sizeof(struct inet_sock),
};
EXPORT_SYMBOL(ping_prot);
#ifdef CONFIG_PROC_FS
static struct sock *ping_get_first(struct seq_file *seq, int start)
{
struct sock *sk;
struct ping_iter_state *state = seq->private;
struct net *net = seq_file_net(seq);
for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
++state->bucket) {
struct hlist_nulls_node *node;
struct hlist_nulls_head *hslot;
hslot = &ping_table.hash[state->bucket];
if (hlist_nulls_empty(hslot))
continue;
sk_nulls_for_each(sk, node, hslot) {
if (net_eq(sock_net(sk), net))
goto found;
}
}
sk = NULL;
found:
return sk;
}
static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
{
struct ping_iter_state *state = seq->private;
struct net *net = seq_file_net(seq);
do {
sk = sk_nulls_next(sk);
} while (sk && (!net_eq(sock_net(sk), net)));
if (!sk)
return ping_get_first(seq, state->bucket + 1);
return sk;
}
static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
{
struct sock *sk = ping_get_first(seq, 0);
if (sk)
while (pos && (sk = ping_get_next(seq, sk)) != NULL)
--pos;
return pos ? NULL : sk;
}
static void *ping_seq_start(struct seq_file *seq, loff_t *pos)
{
struct ping_iter_state *state = seq->private;
state->bucket = 0;
read_lock_bh(&ping_table.lock);
return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
}
static void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct sock *sk;
if (v == SEQ_START_TOKEN)
sk = ping_get_idx(seq, 0);
else
sk = ping_get_next(seq, v);
++*pos;
return sk;
}
static void ping_seq_stop(struct seq_file *seq, void *v)
{
read_unlock_bh(&ping_table.lock);
}
static void ping_format_sock(struct sock *sp, struct seq_file *f,
int bucket, int *len)
{
struct inet_sock *inet = inet_sk(sp);
__be32 dest = inet->inet_daddr;
__be32 src = inet->inet_rcv_saddr;
__u16 destp = ntohs(inet->inet_dport);
__u16 srcp = ntohs(inet->inet_sport);
seq_printf(f, "%5d: %08X:%04X %08X:%04X"
" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n",
bucket, src, srcp, dest, destp, sp->sk_state,
sk_wmem_alloc_get(sp),
sk_rmem_alloc_get(sp),
0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
atomic_read(&sp->sk_refcnt), sp,
atomic_read(&sp->sk_drops), len);
}
static int ping_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN)
seq_printf(seq, "%-127s\n",
" sl local_address rem_address st tx_queue "
"rx_queue tr tm->when retrnsmt uid timeout "
"inode ref pointer drops");
else {
struct ping_iter_state *state = seq->private;
int len;
ping_format_sock(v, seq, state->bucket, &len);
seq_printf(seq, "%*s\n", 127 - len, "");
}
return 0;
}
static const struct seq_operations ping_seq_ops = {
.show = ping_seq_show,
.start = ping_seq_start,
.next = ping_seq_next,
.stop = ping_seq_stop,
};
static int ping_seq_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &ping_seq_ops,
sizeof(struct ping_iter_state));
}
static const struct file_operations ping_seq_fops = {
.open = ping_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
static int ping_proc_register(struct net *net)
{
struct proc_dir_entry *p;
int rc = 0;
p = proc_net_fops_create(net, "icmp", S_IRUGO, &ping_seq_fops);
if (!p)
rc = -ENOMEM;
return rc;
}
static void ping_proc_unregister(struct net *net)
{
proc_net_remove(net, "icmp");
}
static int __net_init ping_proc_init_net(struct net *net)
{
return ping_proc_register(net);
}
static void __net_exit ping_proc_exit_net(struct net *net)
{
ping_proc_unregister(net);
}
static struct pernet_operations ping_net_ops = {
.init = ping_proc_init_net,
.exit = ping_proc_exit_net,
};
int __init ping_proc_init(void)
{
return register_pernet_subsys(&ping_net_ops);
}
void ping_proc_exit(void)
{
unregister_pernet_subsys(&ping_net_ops);
}
#endif
void __init ping_init(void)
{
int i;
for (i = 0; i < PING_HTABLE_SIZE; i++)
INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
rwlock_init(&ping_table.lock);
}
Reference in a new issue View git blame Copy permalink