diff options
| -rw-r--r-- | include/net/netns/ipv4.h | 2 | ||||
| -rw-r--r-- | include/net/ping.h | 57 | ||||
| -rw-r--r-- | net/ipv4/Makefile | 2 | ||||
| -rw-r--r-- | net/ipv4/af_inet.c | 22 | ||||
| -rw-r--r-- | net/ipv4/icmp.c | 12 | ||||
| -rw-r--r-- | net/ipv4/ping.c | 937 | ||||
| -rw-r--r-- | net/ipv4/sysctl_net_ipv4.c | 80 |
7 files changed, 1110 insertions, 2 deletions
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 542195d..d786b4f 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -54,6 +54,8 @@ struct netns_ipv4 { int sysctl_rt_cache_rebuild_count; int current_rt_cache_rebuild_count; + unsigned int sysctl_ping_group_range[2]; + atomic_t rt_genid; atomic_t dev_addr_genid; diff --git a/include/net/ping.h b/include/net/ping.h new file mode 100644 index 0000000..23062c3 --- /dev/null +++ b/include/net/ping.h @@ -0,0 +1,57 @@ +/* + * 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. + * + * Definitions for the "ping" module. + * + * 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. + */ +#ifndef _PING_H +#define _PING_H + +#include <net/netns/hash.h> + +/* PING_HTABLE_SIZE must be power of 2 */ +#define PING_HTABLE_SIZE 64 +#define PING_HTABLE_MASK (PING_HTABLE_SIZE-1) + +#define ping_portaddr_for_each_entry(__sk, node, list) \ + hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) + +/* + * gid_t is either uint or ushort. We want to pass it to + * proc_dointvec_minmax(), so it must not be larger than MAX_INT + */ +#define GID_T_MAX (((gid_t)~0U) >> 1) + +struct ping_table { + struct hlist_nulls_head hash[PING_HTABLE_SIZE]; + rwlock_t lock; +}; + +struct ping_iter_state { + struct seq_net_private p; + int bucket; +}; + +extern struct proto ping_prot; + + +extern void ping_rcv(struct sk_buff *); +extern void ping_err(struct sk_buff *, u32 info); + +extern void inet_get_ping_group_range_net(struct net *net, unsigned int *low, unsigned int *high); + +#ifdef CONFIG_PROC_FS +extern int __init ping_proc_init(void); +extern void ping_proc_exit(void); +#endif + +void __init ping_init(void); + + +#endif /* _PING_H */ diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile index 0dc772d..f2dc69c 100644 --- a/net/ipv4/Makefile +++ b/net/ipv4/Makefile @@ -11,7 +11,7 @@ obj-y := route.o inetpeer.o protocol.o \ datagram.o raw.o udp.o udplite.o \ arp.o icmp.o devinet.o af_inet.o igmp.o \ fib_frontend.o fib_semantics.o fib_trie.o \ - inet_fragment.o + inet_fragment.o ping.o obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o obj-$(CONFIG_PROC_FS) += proc.o diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 851aa05..cc14631 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -105,6 +105,7 @@ #include <net/tcp.h> #include <net/udp.h> #include <net/udplite.h> +#include <net/ping.h> #include <linux/skbuff.h> #include <net/sock.h> #include <net/raw.h> @@ -1008,6 +1009,14 @@ static struct inet_protosw inetsw_array[] = .flags = INET_PROTOSW_PERMANENT, }, + { + .type = SOCK_DGRAM, + .protocol = IPPROTO_ICMP, + .prot = &ping_prot, + .ops = &inet_dgram_ops, + .no_check = UDP_CSUM_DEFAULT, + .flags = INET_PROTOSW_REUSE, + }, { .type = SOCK_RAW, @@ -1527,6 +1536,7 @@ static const struct net_protocol udp_protocol = { static const struct net_protocol icmp_protocol = { .handler = icmp_rcv, + .err_handler = ping_err, .no_policy = 1, .netns_ok = 1, }; @@ -1642,6 +1652,10 @@ static int __init inet_init(void) if (rc) goto out_unregister_udp_proto; + rc = proto_register(&ping_prot, 1); + if (rc) + goto out_unregister_raw_proto; + /* * Tell SOCKET that we are alive... */ @@ -1697,6 +1711,8 @@ static int __init inet_init(void) /* Add UDP-Lite (RFC 3828) */ udplite4_register(); + ping_init(); + /* * Set the ICMP layer up */ @@ -1727,6 +1743,8 @@ static int __init inet_init(void) rc = 0; out: return rc; +out_unregister_raw_proto: + proto_unregister(&raw_prot); out_unregister_udp_proto: proto_unregister(&udp_prot); out_unregister_tcp_proto: @@ -1751,11 +1769,15 @@ static int __init ipv4_proc_init(void) goto out_tcp; if (udp4_proc_init()) goto out_udp; + if (ping_proc_init()) + goto out_ping; if (ip_misc_proc_init()) goto out_misc; out: return rc; out_misc: + ping_proc_exit(); +out_ping: udp4_proc_exit(); out_udp: tcp4_proc_exit(); diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 3314394..3f47585 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -83,6 +83,7 @@ #include <net/tcp.h> #include <net/udp.h> #include <net/raw.h> +#include <net/ping.h> #include <linux/skbuff.h> #include <net/sock.h> #include <linux/errno.h> @@ -781,6 +782,15 @@ static void icmp_redirect(struct sk_buff *skb) iph->saddr, skb->dev); break; } + + /* Ping wants to see redirects. + * Let's pretend they are errors of sorts... */ + if (iph->protocol == IPPROTO_ICMP && + iph->ihl >= 5 && + pskb_may_pull(skb, (iph->ihl<<2)+8)) { + ping_err(skb, icmp_hdr(skb)->un.gateway); + } + out: return; out_err: @@ -1041,7 +1051,7 @@ error: */ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = { [ICMP_ECHOREPLY] = { - .handler = icmp_discard, + .handler = ping_rcv, }, [1] = { .handler = icmp_discard, diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c new file mode 100644 index 0000000..a77e2d7 --- /dev/null +++ b/net/ipv4/ping.c @@ -0,0 +1,937 @@ +/* + * 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 <asm/system.h> +#include <linux/uaccess.h> +#include <asm/ioctls.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 <net/sock.h> +#include <net/ping.h> +#include <net/icmp.h> +#include <net/udp.h> +#include <net/route.h> +#include <net/inet_common.h> +#include <net/checksum.h> + + +struct ping_table ping_table __read_mostly; + +u16 ping_port_rover; + +static inline int ping_hashfn(struct net *net, unsigned num, unsigned 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 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)) { + struct hlist_nulls_head *hslot; + + hslot = ping_hashslot(&ping_table, sock_net(sk), isk->inet_num); + write_lock_bh(&ping_table.lock); + hlist_nulls_del(&sk->sk_nulls_node); + sock_put(sk); + isk->inet_num = isk->inet_sport = 0; + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); + write_unlock_bh(&ping_table.lock); + } +} + +struct sock *ping_v4_lookup(struct net *net, u32 saddr, u32 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 = %ld, dif = %d\n", + (int)ident, (unsigned long)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 = %ld, dif = %d\n", sk, + (int)isk->inet_num, (unsigned long)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 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; + + inet_get_ping_group_range_net(net, range, range+1); + 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++) { + group = group_info->blocks[i][j]; + if (range[0] <= group && group <= range[1]) + 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 == 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 = %ld, dif = %d\n", + (int)isk->inet_num, + (unsigned long) 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) { + ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); + 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; + u32 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); +} + +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; + u32 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; + } + + 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; +} + +/* + * IOCTL requests applicable to the UDP^H^H^HICMP protocol + */ + +int ping_ioctl(struct sock *sk, int cmd, unsigned long arg) +{ + pr_debug("ping_ioctl(sk=%p,sk->num=%u,cmd=%d,arg=%lu)\n", + inet_sk(sk), inet_sk(sk)->inet_num, cmd, arg); + switch (cmd) { + case SIOCOUTQ: + case SIOCINQ: + return udp_ioctl(sk, cmd, arg); + default: + return -ENOIOCTLCMD; + } +} + +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); + + 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) { + ICMP_INC_STATS_BH(sock_net(sk), ICMP_MIB_INERRORS); + 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); + u32 saddr = iph->saddr; + u32 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, + .ioctl = ping_ioctl, + .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 = &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); +} diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 321e6e8..28e8273 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -13,6 +13,7 @@ #include <linux/seqlock.h> #include <linux/init.h> #include <linux/slab.h> +#include <linux/nsproxy.h> #include <net/snmp.h> #include <net/icmp.h> #include <net/ip.h> @@ -21,6 +22,7 @@ #include <net/udp.h> #include <net/cipso_ipv4.h> #include <net/inet_frag.h> +#include <net/ping.h> static int zero; static int tcp_retr1_max = 255; @@ -30,6 +32,8 @@ static int tcp_adv_win_scale_min = -31; static int tcp_adv_win_scale_max = 31; static int ip_ttl_min = 1; static int ip_ttl_max = 255; +static int ip_ping_group_range_min[] = { 0, 0 }; +static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX }; /* Update system visible IP port range */ static void set_local_port_range(int range[2]) @@ -68,6 +72,65 @@ static int ipv4_local_port_range(ctl_table *table, int write, return ret; } + +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 seq; + do { + seq = read_seqbegin(&sysctl_local_ports.lock); + + *low = data[0]; + *high = data[1]; + } while (read_seqretry(&sysctl_local_ports.lock, seq)); +} + +void inet_get_ping_group_range_table(struct ctl_table *table, gid_t *low, gid_t *high) +{ + gid_t *data = table->data; + unsigned seq; + do { + seq = read_seqbegin(&sysctl_local_ports.lock); + + *low = data[0]; + *high = data[1]; + } while (read_seqretry(&sysctl_local_ports.lock, seq)); +} + +/* Update system visible IP port range */ +static void set_ping_group_range(struct ctl_table *table, int range[2]) +{ + gid_t *data = table->data; + write_seqlock(&sysctl_local_ports.lock); + data[0] = range[0]; + data[1] = range[1]; + write_sequnlock(&sysctl_local_ports.lock); +} + +/* Validate changes from /proc interface. */ +static int ipv4_ping_group_range(ctl_table *table, int write, + void __user *buffer, + size_t *lenp, loff_t *ppos) +{ + int ret; + gid_t range[2]; + ctl_table tmp = { + .data = &range, + .maxlen = sizeof(range), + .mode = table->mode, + .extra1 = &ip_ping_group_range_min, + .extra2 = &ip_ping_group_range_max, + }; + + inet_get_ping_group_range_table(table, range, range + 1); + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + + if (write && ret == 0) + set_ping_group_range(table, range); + + return ret; +} + static int proc_tcp_congestion_control(ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { @@ -677,6 +740,13 @@ static struct ctl_table ipv4_net_table[] = { .mode = 0644, .proc_handler = proc_dointvec }, + { + .procname = "ping_group_range", + .data = &init_net.ipv4.sysctl_ping_group_range, + .maxlen = sizeof(init_net.ipv4.sysctl_ping_group_range), + .mode = 0644, + .proc_handler = ipv4_ping_group_range, + }, { } }; @@ -711,8 +781,18 @@ static __net_init int ipv4_sysctl_init_net(struct net *net) &net->ipv4.sysctl_icmp_ratemask; table[6].data = &net->ipv4.sysctl_rt_cache_rebuild_count; + table[7].data = + &net->ipv4.sysctl_ping_group_range; + } + /* + * Sane defaults - nobody may create ping sockets. + * Boot scripts should set this to distro-specific group. + */ + net->ipv4.sysctl_ping_group_range[0] = 1; + net->ipv4.sysctl_ping_group_range[1] = 0; + net->ipv4.sysctl_rt_cache_rebuild_count = 4; net->ipv4.ipv4_hdr = register_net_sysctl_table(net, |
