// 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 <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 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_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); 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); write_lock_bh(&ping_table.lock); if (sk_hashed(sk)) { hlist_nulls_del(&sk->sk_nulls_node); sk_nulls_node_init(&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 } else { 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, 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); /* 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; 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)); 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 ((!inet_can_nonlocal_bind(net, isk) && 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 -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; } } 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 } } 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 = %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_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) { 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) { fraglen -= sizeof(struct icmphdr); if (fraglen < 0) BUG(); if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), fraglen, &pfh->wcheck, &pfh->msg->msg_iter)) return -EFAULT; } else if (offset < sizeof(struct icmphdr)) { BUG(); } else { 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 = 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); 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; 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); 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 || netif_index_is_l3_master(sock_net(sk), 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, ipc.sockc.mark, tos, RT_SCOPE_UNIVERSE, sk->sk_protocol, inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, sk->sk_uid); 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.msg = msg; 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); 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 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) return inet_recv_error(sk, msg, len, addr_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_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 (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, 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) && 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. */ bool 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) { struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); pr_debug("rcv on socket %p\n", sk); if (skb2) ping_queue_rcv_skb(sk, skb2); sock_put(sk); return true; } pr_debug("no socket, dropping\n"); return false; } 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) __acquires(ping_table.lock) { 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) __releases(ping_table.lock) { 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 %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_NULLS_HEAD(&ping_table.hash[i], i); rwlock_init(&ping_table.lock); }