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linux/net/ipv4/ping.c
Jakub Kicinski a3c2dd9648 bpf-next-for-netdev 
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2023-10-16

We've added 90 non-merge commits during the last 25 day(s) which contain
a total of 120 files changed, 3519 insertions(+), 895 deletions(-).

The main changes are:

1) Add missed stats for kprobes to retrieve the number of missed kprobe
   executions and subsequent executions of BPF programs, from Jiri Olsa.

2) Add cgroup BPF sockaddr hooks for unix sockets. The use case is
   for systemd to reimplement the LogNamespace feature which allows
   running multiple instances of systemd-journald to process the logs
   of different services, from Daan De Meyer.

3) Implement BPF CPUv4 support for s390x BPF JIT, from Ilya Leoshkevich.

4) Improve BPF verifier log output for scalar registers to better
   disambiguate their internal state wrt defaults vs min/max values
   matching, from Andrii Nakryiko.

5) Extend the BPF fib lookup helpers for IPv4/IPv6 to support retrieving
   the source IP address with a new BPF_FIB_LOOKUP_SRC flag,
   from Martynas Pumputis.

6) Add support for open-coded task_vma iterator to help with symbolization
   for BPF-collected user stacks, from Dave Marchevsky.

7) Add libbpf getters for accessing individual BPF ring buffers which
   is useful for polling them individually, for example, from Martin Kelly.

8) Extend AF_XDP selftests to validate the SHARED_UMEM feature,
   from Tushar Vyavahare.

9) Improve BPF selftests cross-building support for riscv arch,
   from Björn Töpel.

10) Add the ability to pin a BPF timer to the same calling CPU,
   from David Vernet.

11) Fix libbpf's bpf_tracing.h macros for riscv to use the generic
   implementation of PT_REGS_SYSCALL_REGS() to access syscall arguments,
   from Alexandre Ghiti.

12) Extend libbpf to support symbol versioning for uprobes, from Hengqi Chen.

13) Fix bpftool's skeleton code generation to guarantee that ELF data
    is 8 byte aligned, from Ian Rogers.

14) Inherit system-wide cpu_mitigations_off() setting for Spectre v1/v4
    security mitigations in BPF verifier, from Yafang Shao.

15) Annotate struct bpf_stack_map with __counted_by attribute to prepare
    BPF side for upcoming __counted_by compiler support, from Kees Cook.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (90 commits)
  bpf: Ensure proper register state printing for cond jumps
  bpf: Disambiguate SCALAR register state output in verifier logs
  selftests/bpf: Make align selftests more robust
  selftests/bpf: Improve missed_kprobe_recursion test robustness
  selftests/bpf: Improve percpu_alloc test robustness
  selftests/bpf: Add tests for open-coded task_vma iter
  bpf: Introduce task_vma open-coded iterator kfuncs
  selftests/bpf: Rename bpf_iter_task_vma.c to bpf_iter_task_vmas.c
  bpf: Don't explicitly emit BTF for struct btf_iter_num
  bpf: Change syscall_nr type to int in struct syscall_tp_t
  net/bpf: Avoid unused "sin_addr_len" warning when CONFIG_CGROUP_BPF is not set
  bpf: Avoid unnecessary audit log for CPU security mitigations
  selftests/bpf: Add tests for cgroup unix socket address hooks
  selftests/bpf: Make sure mount directory exists
  documentation/bpf: Document cgroup unix socket address hooks
  bpftool: Add support for cgroup unix socket address hooks
  libbpf: Add support for cgroup unix socket address hooks
  bpf: Implement cgroup sockaddr hooks for unix sockets
  bpf: Add bpf_sock_addr_set_sun_path() to allow writing unix sockaddr from bpf
  bpf: Propagate modified uaddrlen from cgroup sockaddr programs
  ...
====================

Link: https://lore.kernel.org/r/20231016204803.30153-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-16 21:05:33 -07:00

1196 lines
28 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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
*
* 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/icmp.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/export.h>
#include <linux/bpf-cgroup.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>
#if IS_ENABLED(CONFIG_IPV6)
#include <linux/in6.h>
#include <linux/icmpv6.h>
#include <net/addrconf.h>
#include <net/ipv6.h>
#include <net/transp_v6.h>
#endif
struct ping_table {
struct hlist_head hash[PING_HTABLE_SIZE];
spinlock_t lock;
};
static struct ping_table ping_table;
struct pingv6_ops pingv6_ops;
EXPORT_SYMBOL_GPL(pingv6_ops);
static u16 ping_port_rover;
static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
{
u32 res = (num + net_hash_mix(net)) & mask;
pr_debug("hash(%u) = %u\n", num, res);
return res;
}
EXPORT_SYMBOL_GPL(ping_hash);
static inline struct hlist_head *ping_hashslot(struct ping_table *table,
struct net *net, unsigned int num)
{
return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
}
int ping_get_port(struct sock *sk, unsigned short ident)
{
struct inet_sock *isk, *isk2;
struct hlist_head *hlist;
struct sock *sk2 = NULL;
isk = inet_sk(sk);
spin_lock(&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);
sk_for_each(sk2, 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);
sk_for_each(sk2, hlist) {
isk2 = inet_sk(sk2);
/* BUG? Why is this reuse and not reuseaddr? ping.c
* doesn't turn off SO_REUSEADDR, and it doesn't expect
* that other ping processes can steal its packets.
*/
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");
sk_add_node_rcu(sk, hlist);
sock_set_flag(sk, SOCK_RCU_FREE);
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
}
spin_unlock(&ping_table.lock);
return 0;
fail:
spin_unlock(&ping_table.lock);
return -EADDRINUSE;
}
EXPORT_SYMBOL_GPL(ping_get_port);
int ping_hash(struct sock *sk)
{
pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
BUG(); /* "Please do not press this button again." */
return 0;
}
void ping_unhash(struct sock *sk)
{
struct inet_sock *isk = inet_sk(sk);
pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
spin_lock(&ping_table.lock);
if (sk_del_node_init_rcu(sk)) {
isk->inet_num = 0;
isk->inet_sport = 0;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
}
spin_unlock(&ping_table.lock);
}
EXPORT_SYMBOL_GPL(ping_unhash);
/* Called under rcu_read_lock() */
static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
{
struct hlist_head *hslot = ping_hashslot(&ping_table, net, ident);
struct sock *sk = NULL;
struct inet_sock *isk;
int dif, sdif;
if (skb->protocol == htons(ETH_P_IP)) {
dif = inet_iif(skb);
sdif = inet_sdif(skb);
pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
(int)ident, &ip_hdr(skb)->daddr, dif);
#if IS_ENABLED(CONFIG_IPV6)
} else if (skb->protocol == htons(ETH_P_IPV6)) {
dif = inet6_iif(skb);
sdif = inet6_sdif(skb);
pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
(int)ident, &ipv6_hdr(skb)->daddr, dif);
#endif
} else {
return NULL;
}
sk_for_each_rcu(sk, hslot) {
isk = inet_sk(sk);
pr_debug("iterate\n");
if (isk->inet_num != ident)
continue;
if (skb->protocol == htons(ETH_P_IP) &&
sk->sk_family == AF_INET) {
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);
if (isk->inet_rcv_saddr &&
isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
continue;
#if IS_ENABLED(CONFIG_IPV6)
} else if (skb->protocol == htons(ETH_P_IPV6) &&
sk->sk_family == AF_INET6) {
pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
(int) isk->inet_num,
&sk->sk_v6_rcv_saddr,
sk->sk_bound_dev_if);
if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
!ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
&ipv6_hdr(skb)->daddr))
continue;
#endif
} else {
continue;
}
if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
sk->sk_bound_dev_if != sdif)
continue;
goto exit;
}
sk = NULL;
exit:
return sk;
}
static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
kgid_t *high)
{
kgid_t *data = net->ipv4.ping_group_range.range;
unsigned int seq;
do {
seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
*low = data[0];
*high = data[1];
} while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
}
int ping_init_sock(struct sock *sk)
{
struct net *net = sock_net(sk);
kgid_t group = current_egid();
struct group_info *group_info;
int i;
kgid_t low, high;
int ret = 0;
if (sk->sk_family == AF_INET6)
sk->sk_ipv6only = 1;
inet_get_ping_group_range_net(net, &low, &high);
if (gid_lte(low, group) && gid_lte(group, high))
return 0;
group_info = get_current_groups();
for (i = 0; i < group_info->ngroups; i++) {
kgid_t gid = group_info->gid[i];
if (gid_lte(low, gid) && gid_lte(gid, high))
goto out_release_group;
}
ret = -EACCES;
out_release_group:
put_group_info(group_info);
return ret;
}
EXPORT_SYMBOL_GPL(ping_init_sock);
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", refcount_read(&sk->sk_refcnt));
sk_common_release(sk);
}
EXPORT_SYMBOL_GPL(ping_close);
static int ping_pre_connect(struct sock *sk, struct sockaddr *uaddr,
int addr_len)
{
/* This check is replicated from __ip4_datagram_connect() and
* intended to prevent BPF program called below from accessing bytes
* that are out of the bound specified by user in addr_len.
*/
if (addr_len < sizeof(struct sockaddr_in))
return -EINVAL;
return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr, &addr_len);
}
/* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
struct sockaddr *uaddr, int addr_len)
{
struct net *net = sock_net(sk);
if (sk->sk_family == AF_INET) {
struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
u32 tb_id = RT_TABLE_LOCAL;
int chk_addr_ret;
if (addr_len < sizeof(*addr))
return -EINVAL;
if (addr->sin_family != AF_INET &&
!(addr->sin_family == AF_UNSPEC &&
addr->sin_addr.s_addr == htonl(INADDR_ANY)))
return -EAFNOSUPPORT;
pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
return 0;
tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
if (chk_addr_ret == RTN_MULTICAST ||
chk_addr_ret == RTN_BROADCAST ||
(chk_addr_ret != RTN_LOCAL &&
!inet_can_nonlocal_bind(net, isk)))
return -EADDRNOTAVAIL;
#if IS_ENABLED(CONFIG_IPV6)
} else if (sk->sk_family == AF_INET6) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
int addr_type, scoped, has_addr;
struct net_device *dev = NULL;
if (addr_len < sizeof(*addr))
return -EINVAL;
if (addr->sin6_family != AF_INET6)
return -EAFNOSUPPORT;
pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
addr_type = ipv6_addr_type(&addr->sin6_addr);
scoped = __ipv6_addr_needs_scope_id(addr_type);
if ((addr_type != IPV6_ADDR_ANY &&
!(addr_type & IPV6_ADDR_UNICAST)) ||
(scoped && !addr->sin6_scope_id))
return -EINVAL;
rcu_read_lock();
if (addr->sin6_scope_id) {
dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
if (!dev) {
rcu_read_unlock();
return -ENODEV;
}
}
if (!dev && sk->sk_bound_dev_if) {
dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
if (!dev) {
rcu_read_unlock();
return -ENODEV;
}
}
has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
scoped);
rcu_read_unlock();
if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
addr_type == IPV6_ADDR_ANY))
return -EADDRNOTAVAIL;
if (scoped)
sk->sk_bound_dev_if = addr->sin6_scope_id;
#endif
} else {
return -EAFNOSUPPORT;
}
return 0;
}
static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
{
if (saddr->sa_family == AF_INET) {
struct inet_sock *isk = inet_sk(sk);
struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
#if IS_ENABLED(CONFIG_IPV6)
} else if (saddr->sa_family == AF_INET6) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
struct ipv6_pinfo *np = inet6_sk(sk);
sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
#endif
}
}
/*
* 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.
*/
int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
struct inet_sock *isk = inet_sk(sk);
unsigned short snum;
int err;
int dif = sk->sk_bound_dev_if;
err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
if (err)
return err;
lock_sock(sk);
err = -EINVAL;
if (isk->inet_num != 0)
goto out;
err = -EADDRINUSE;
snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
if (ping_get_port(sk, snum) != 0) {
/* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */
sk->sk_bound_dev_if = dif;
goto out;
}
ping_set_saddr(sk, uaddr);
pr_debug("after bind(): num = %hu, dif = %d\n",
isk->inet_num,
sk->sk_bound_dev_if);
err = 0;
if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
#endif
if (snum)
sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
isk->inet_sport = htons(isk->inet_num);
isk->inet_daddr = 0;
isk->inet_dport = 0;
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6)
memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
#endif
sk_dst_reset(sk);
out:
release_sock(sk);
pr_debug("ping_v4_bind -> %d\n", err);
return err;
}
EXPORT_SYMBOL_GPL(ping_bind);
/*
* Is this a supported type of ICMP message?
*/
static inline int ping_supported(int family, int type, int code)
{
return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
(family == AF_INET && type == ICMP_EXT_ECHO && code == 0) ||
(family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) ||
(family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0);
}
/*
* This routine is called by the ICMP module when it gets some
* sort of error condition.
*/
void ping_err(struct sk_buff *skb, int offset, u32 info)
{
int family;
struct icmphdr *icmph;
struct inet_sock *inet_sock;
int type;
int code;
struct net *net = dev_net(skb->dev);
struct sock *sk;
int harderr;
int err;
if (skb->protocol == htons(ETH_P_IP)) {
family = AF_INET;
type = icmp_hdr(skb)->type;
code = icmp_hdr(skb)->code;
icmph = (struct icmphdr *)(skb->data + offset);
} else if (skb->protocol == htons(ETH_P_IPV6)) {
family = AF_INET6;
type = icmp6_hdr(skb)->icmp6_type;
code = icmp6_hdr(skb)->icmp6_code;
icmph = (struct icmphdr *) (skb->data + offset);
} else {
BUG();
}
/* We assume the packet has already been checked by icmp_unreach */
if (!ping_supported(family, icmph->type, icmph->code))
return;
pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
skb->protocol, type, code, ntohs(icmph->un.echo.id),
ntohs(icmph->un.echo.sequence));
sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
if (!sk) {
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);
if (skb->protocol == htons(ETH_P_IP)) {
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 */
ipv4_sk_update_pmtu(skb, sk, info);
if (READ_ONCE(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 */
ipv4_sk_redirect(skb, sk);
err = EREMOTEIO;
break;
}
#if IS_ENABLED(CONFIG_IPV6)
} else if (skb->protocol == htons(ETH_P_IPV6)) {
harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
#endif
}
/*
* RFC1122: OK. Passes ICMP errors back to application, as per
* 4.1.3.3.
*/
if ((family == AF_INET && !inet_test_bit(RECVERR, sk)) ||
(family == AF_INET6 && !inet6_test_bit(RECVERR6, sk))) {
if (!harderr || sk->sk_state != TCP_ESTABLISHED)
goto out;
} else {
if (family == AF_INET) {
ip_icmp_error(sk, skb, err, 0 /* no remote port */,
info, (u8 *)icmph);
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
info, (u8 *)icmph);
#endif
}
}
sk->sk_err = err;
sk_error_report(sk);
out:
return;
}
EXPORT_SYMBOL_GPL(ping_err);
/*
* Copy and checksum an ICMP Echo packet from user space into a buffer
* starting from the payload.
*/
int ping_getfrag(void *from, char *to,
int offset, int fraglen, int odd, struct sk_buff *skb)
{
struct pingfakehdr *pfh = from;
if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
&pfh->msg->msg_iter))
return -EFAULT;
#if IS_ENABLED(CONFIG_IPV6)
/* For IPv6, checksum each skb as we go along, as expected by
* icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
* wcheck, it will be finalized in ping_v4_push_pending_frames.
*/
if (pfh->family == AF_INET6) {
skb->csum = csum_block_add(skb->csum, pfh->wcheck, odd);
skb->ip_summed = CHECKSUM_NONE;
pfh->wcheck = 0;
}
#endif
return 0;
}
EXPORT_SYMBOL_GPL(ping_getfrag);
static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
struct flowi4 *fl4)
{
struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
if (!skb)
return 0;
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);
}
int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
void *user_icmph, size_t icmph_len)
{
u8 type, code;
if (len > 0xFFFF)
return -EMSGSIZE;
/* Must have at least a full ICMP header. */
if (len < icmph_len)
return -EINVAL;
/*
* 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! The ICMP header is consumed.
*/
if (memcpy_from_msg(user_icmph, msg, icmph_len))
return -EFAULT;
if (family == AF_INET) {
type = ((struct icmphdr *) user_icmph)->type;
code = ((struct icmphdr *) user_icmph)->code;
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
#endif
} else {
BUG();
}
if (!ping_supported(family, type, code))
return -EINVAL;
return 0;
}
EXPORT_SYMBOL_GPL(ping_common_sendmsg);
static int ping_v4_sendmsg(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, scope;
int err;
pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
sizeof(user_icmph));
if (err)
return err;
/*
* Get and verify the address.
*/
if (msg->msg_name) {
DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
if (msg->msg_namelen < sizeof(*usin))
return -EINVAL;
if (usin->sin_family != AF_INET)
return -EAFNOSUPPORT;
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 */
}
ipcm_init_sk(&ipc, inet);
if (msg->msg_controllen) {
err = ip_cmsg_send(sk, msg, &ipc, false);
if (unlikely(err)) {
kfree(ipc.opt);
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) {
err = -EINVAL;
goto out_free;
}
faddr = ipc.opt->opt.faddr;
}
tos = get_rttos(&ipc, inet);
scope = ip_sendmsg_scope(inet, &ipc, msg);
if (ipv4_is_multicast(daddr)) {
if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
ipc.oif = READ_ONCE(inet->mc_index);
if (!saddr)
saddr = READ_ONCE(inet->mc_addr);
} else if (!ipc.oif)
ipc.oif = READ_ONCE(inet->uc_index);
flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, scope,
sk->sk_protocol, inet_sk_flowi_flags(sk), faddr,
saddr, 0, 0, sk->sk_uid);
fl4.fl4_icmp_type = user_icmph.type;
fl4.fl4_icmp_code = user_icmph.code;
security_sk_classify_flow(sk, flowi4_to_flowi_common(&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(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.msg = msg;
pfh.wcheck = 0;
pfh.family = AF_INET;
err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
sizeof(struct icmphdr), &ipc, &rt,
msg->msg_flags);
if (err)
ip_flush_pending_frames(sk);
else
err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
release_sock(sk);
out:
ip_rt_put(rt);
out_free:
if (free)
kfree(ipc.opt);
if (!err) {
icmp_out_count(sock_net(sk), user_icmph.type);
return len;
}
return err;
do_confirm:
if (msg->msg_flags & MSG_PROBE)
dst_confirm_neigh(&rt->dst, &fl4.daddr);
if (!(msg->msg_flags & MSG_PROBE) || len)
goto back_from_confirm;
err = 0;
goto out;
}
int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
int *addr_len)
{
struct inet_sock *isk = inet_sk(sk);
int family = sk->sk_family;
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 (flags & MSG_ERRQUEUE)
return inet_recv_error(sk, msg, len, addr_len);
skb = skb_recv_datagram(sk, flags, &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_msg(skb, 0, msg, copied);
if (err)
goto done;
sock_recv_timestamp(msg, sk, skb);
/* Copy the address and add cmsg data. */
if (family == AF_INET) {
DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
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));
*addr_len = sizeof(*sin);
}
if (inet_cmsg_flags(isk))
ip_cmsg_recv(msg, skb);
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
struct ipv6hdr *ip6 = ipv6_hdr(skb);
DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
if (sin6) {
sin6->sin6_family = AF_INET6;
sin6->sin6_port = 0;
sin6->sin6_addr = ip6->saddr;
sin6->sin6_flowinfo = 0;
if (inet6_test_bit(SNDFLOW, sk))
sin6->sin6_flowinfo = ip6_flowinfo(ip6);
sin6->sin6_scope_id =
ipv6_iface_scope_id(&sin6->sin6_addr,
inet6_iif(skb));
*addr_len = sizeof(*sin6);
}
if (inet6_sk(sk)->rxopt.all)
pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
if (skb->protocol == htons(ETH_P_IPV6) &&
inet6_sk(sk)->rxopt.all)
pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
else if (skb->protocol == htons(ETH_P_IP) &&
inet_cmsg_flags(isk))
ip_cmsg_recv(msg, skb);
#endif
} else {
BUG();
}
err = copied;
done:
skb_free_datagram(sk, skb);
out:
pr_debug("ping_recvmsg -> %d\n", err);
return err;
}
EXPORT_SYMBOL_GPL(ping_recvmsg);
static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk,
struct sk_buff *skb)
{
enum skb_drop_reason reason;
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_reason(sk, skb, &reason) < 0) {
kfree_skb_reason(skb, reason);
pr_debug("ping_queue_rcv_skb -> failed\n");
return reason;
}
return SKB_NOT_DROPPED_YET;
}
int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
return __ping_queue_rcv_skb(sk, skb) ? -1 : 0;
}
EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
/*
* All we need to do is get the socket.
*/
enum skb_drop_reason ping_rcv(struct sk_buff *skb)
{
enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET;
struct sock *sk;
struct net *net = dev_net(skb->dev);
struct icmphdr *icmph = icmp_hdr(skb);
/* 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_lookup(net, skb, ntohs(icmph->un.echo.id));
if (sk) {
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
pr_debug("rcv on socket %p\n", sk);
if (skb2)
reason = __ping_queue_rcv_skb(sk, skb2);
else
reason = SKB_DROP_REASON_NOMEM;
}
if (reason)
pr_debug("no socket, dropping\n");
return reason;
}
EXPORT_SYMBOL_GPL(ping_rcv);
struct proto ping_prot = {
.name = "PING",
.owner = THIS_MODULE,
.init = ping_init_sock,
.close = ping_close,
.pre_connect = ping_pre_connect,
.connect = ip4_datagram_connect,
.disconnect = __udp_disconnect,
.setsockopt = ip_setsockopt,
.getsockopt = ip_getsockopt,
.sendmsg = ping_v4_sendmsg,
.recvmsg = ping_recvmsg,
.bind = ping_bind,
.backlog_rcv = ping_queue_rcv_skb,
.release_cb = ip4_datagram_release_cb,
.hash = ping_hash,
.unhash = ping_unhash,
.get_port = ping_get_port,
.put_port = ping_unhash,
.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_head *hslot;
hslot = &ping_table.hash[state->bucket];
if (hlist_empty(hslot))
continue;
sk_for_each(sk, hslot) {
if (net_eq(sock_net(sk), net) &&
sk->sk_family == state->family)
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_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;
}
void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
__acquires(ping_table.lock)
{
struct ping_iter_state *state = seq->private;
state->bucket = 0;
state->family = family;
spin_lock(&ping_table.lock);
return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
}
EXPORT_SYMBOL_GPL(ping_seq_start);
static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
{
return ping_seq_start(seq, pos, AF_INET);
}
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;
}
EXPORT_SYMBOL_GPL(ping_seq_next);
void ping_seq_stop(struct seq_file *seq, void *v)
__releases(ping_table.lock)
{
spin_unlock(&ping_table.lock);
}
EXPORT_SYMBOL_GPL(ping_seq_stop);
static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
int bucket)
{
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 %5u %8d %lu %d %pK %u",
bucket, src, srcp, dest, destp, sp->sk_state,
sk_wmem_alloc_get(sp),
sk_rmem_alloc_get(sp),
0, 0L, 0,
from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
0, sock_i_ino(sp),
refcount_read(&sp->sk_refcnt), sp,
atomic_read(&sp->sk_drops));
}
static int ping_v4_seq_show(struct seq_file *seq, void *v)
{
seq_setwidth(seq, 127);
if (v == SEQ_START_TOKEN)
seq_puts(seq, " 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;
ping_v4_format_sock(v, seq, state->bucket);
}
seq_pad(seq, '\n');
return 0;
}
static const struct seq_operations ping_v4_seq_ops = {
.start = ping_v4_seq_start,
.show = ping_v4_seq_show,
.next = ping_seq_next,
.stop = ping_seq_stop,
};
static int __net_init ping_v4_proc_init_net(struct net *net)
{
if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
sizeof(struct ping_iter_state)))
return -ENOMEM;
return 0;
}
static void __net_exit ping_v4_proc_exit_net(struct net *net)
{
remove_proc_entry("icmp", net->proc_net);
}
static struct pernet_operations ping_v4_net_ops = {
.init = ping_v4_proc_init_net,
.exit = ping_v4_proc_exit_net,
};
int __init ping_proc_init(void)
{
return register_pernet_subsys(&ping_v4_net_ops);
}
void ping_proc_exit(void)
{
unregister_pernet_subsys(&ping_v4_net_ops);
}
#endif
void __init ping_init(void)
{
int i;
for (i = 0; i < PING_HTABLE_SIZE; i++)
INIT_HLIST_HEAD(&ping_table.hash[i]);
spin_lock_init(&ping_table.lock);
}
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