diff options
Diffstat (limited to 'net/ipv4/ping.c')
| -rw-r--r-- | net/ipv4/ping.c | 1218 |
1 files changed, 1218 insertions, 0 deletions
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c new file mode 100644 index 00000000000..044a0ddf6a7 --- /dev/null +++ b/net/ipv4/ping.c @@ -0,0 +1,1218 @@ +/* + * 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/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> + +#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_nulls_head hash[PING_HTABLE_SIZE]; + rwlock_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 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; +} +EXPORT_SYMBOL_GPL(ping_hash); + +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)]; +} + +int ping_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); + + /* 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"); + 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; +} +EXPORT_SYMBOL_GPL(ping_get_port); + +void 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." */ +} + +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); + 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); + } +} +EXPORT_SYMBOL_GPL(ping_unhash); + +static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) +{ + struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); + struct sock *sk = NULL; + struct inet_sock *isk; + struct hlist_nulls_node *hnode; + int dif = skb->dev->ifindex; + + if (skb->protocol == htons(ETH_P_IP)) { + 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)) { + pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", + (int)ident, &ipv6_hdr(skb)->daddr, dif); +#endif + } + + read_lock_bh(&ping_table.lock); + + ping_portaddr_for_each_entry(sk, hnode, 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 + } + + 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, 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, j, count; + kgid_t low, high; + int ret = 0; + + 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(); + count = group_info->ngroups; + 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)) + goto out_release_group; + } + + count -= cp_count; + } + + 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", sk->sk_refcnt.counter); + + sk_common_release(sk); +} +EXPORT_SYMBOL_GPL(ping_close); + +/* 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; + int chk_addr_ret; + + if (addr_len < sizeof(*addr)) + return -EINVAL; + + pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", + sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); + + chk_addr_ret = inet_addr_type(net, 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; + +#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 -EINVAL; + + 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; + } + } + has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, + scoped); + rcu_read_unlock(); + + if (!(isk->freebind || isk->transparent || 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 + } +} + +static void ping_clear_saddr(struct sock *sk, int dif) +{ + sk->sk_bound_dev_if = dif; + if (sk->sk_family == AF_INET) { + struct inet_sock *isk = inet_sk(sk); + isk->inet_rcv_saddr = isk->inet_saddr = 0; +#if IS_ENABLED(CONFIG_IPV6) + } else if (sk->sk_family == AF_INET6) { + struct ipv6_pinfo *np = inet6_sk(sk); + memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); + memset(&np->saddr, 0, sizeof(np->saddr)); +#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; + ping_set_saddr(sk, uaddr); + snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); + if (ping_get_port(sk, snum) != 0) { + ping_clear_saddr(sk, dif); + goto out; + } + + pr_debug("after bind(): num = %d, dif = %d\n", + (int)isk->inet_num, + (int)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_INET6 && type == ICMPV6_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 == 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); + + 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 (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_sock->recverr) || + (family == AF_INET6 && !inet6_sk(sk)->recverr)) { + 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->sk_error_report(sk); +out: + sock_put(sk); +} +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 = (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; + } else if (offset < sizeof(struct icmphdr)) { + BUG(); + } else { + if (csum_partial_copy_fromiovecend + (to, pfh->iov, offset - sizeof(struct icmphdr), + fraglen, &pfh->wcheck)) + 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 = pfh->wcheck; + 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); + + 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; + + /* + * 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_fromiovec(user_icmph, msg->msg_iov, 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 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_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 -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; + ipc.ttl = 0; + ipc.tos = -1; + + sock_tx_timestamp(sk, &ipc.tx_flags); + + if (msg->msg_controllen) { + err = ip_cmsg_send(sock_net(sk), msg, &ipc, false); + 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 = get_rttos(&ipc, inet); + 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(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; + pfh.family = AF_INET; + + 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_v4_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; +} + +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); + 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) { + if (family == AF_INET) { + return ip_recv_error(sk, msg, len, addr_len); +#if IS_ENABLED(CONFIG_IPV6) + } else if (family == AF_INET6) { + return pingv6_ops.ipv6_recv_error(sk, msg, len, + addr_len); +#endif + } + } + + 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 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 (isk->cmsg_flags) + ip_cmsg_recv(msg, skb); + +#if IS_ENABLED(CONFIG_IPV6) + } else if (family == AF_INET6) { + struct ipv6_pinfo *np = inet6_sk(sk); + 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 (np->sndflow) + sin6->sin6_flowinfo = ip6_flowinfo(ip6); + sin6->sin6_scope_id = + ipv6_iface_scope_id(&sin6->sin6_addr, + IP6CB(skb)->iif); + *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) && isk->cmsg_flags) + 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); + +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; +} +EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); + + +/* + * 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 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 != 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. */ +} +EXPORT_SYMBOL_GPL(ping_rcv); + +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_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, + .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) && + 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_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; +} + +void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) +{ + struct ping_iter_state *state = seq->private; + state->bucket = 0; + state->family = family; + + read_lock_bh(&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) +{ + read_unlock_bh(&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 %d", + 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), + atomic_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 = { + .show = ping_v4_seq_show, + .start = ping_v4_seq_start, + .next = ping_seq_next, + .stop = ping_seq_stop, +}; + +static int ping_seq_open(struct inode *inode, struct file *file) +{ + struct ping_seq_afinfo *afinfo = PDE_DATA(inode); + return seq_open_net(inode, file, &afinfo->seq_ops, + sizeof(struct ping_iter_state)); +} + +const struct file_operations ping_seq_fops = { + .open = ping_seq_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_net, +}; +EXPORT_SYMBOL_GPL(ping_seq_fops); + +static struct ping_seq_afinfo ping_v4_seq_afinfo = { + .name = "icmp", + .family = AF_INET, + .seq_fops = &ping_seq_fops, + .seq_ops = { + .start = ping_v4_seq_start, + .show = ping_v4_seq_show, + .next = ping_seq_next, + .stop = ping_seq_stop, + }, +}; + +int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo) +{ + struct proc_dir_entry *p; + p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, + afinfo->seq_fops, afinfo); + if (!p) + return -ENOMEM; + return 0; +} +EXPORT_SYMBOL_GPL(ping_proc_register); + +void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo) +{ + remove_proc_entry(afinfo->name, net->proc_net); +} +EXPORT_SYMBOL_GPL(ping_proc_unregister); + +static int __net_init ping_v4_proc_init_net(struct net *net) +{ + return ping_proc_register(net, &ping_v4_seq_afinfo); +} + +static void __net_exit ping_v4_proc_exit_net(struct net *net) +{ + ping_proc_unregister(net, &ping_v4_seq_afinfo); +} + +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_NULLS_HEAD(&ping_table.hash[i], i); + rwlock_init(&ping_table.lock); +} |