cregit-Linux how code gets into the kernel

Release 4.8 net/ipv4/ping.c

Directory: net/ipv4
/*
 * 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 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; }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov3986.67%150.00%
eric dumazeteric dumazet613.33%150.00%
Total45100.00%2100.00%

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)]; }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov3897.44%150.00%
eric dumazeteric dumazet12.56%150.00%
Total39100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov31599.37%150.00%
lorenzo colittilorenzo colitti20.63%150.00%
Total317100.00%2100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov2379.31%133.33%
craig gallekcraig gallek413.79%133.33%
lorenzo colittilorenzo colitti26.90%133.33%
Total29100.00%3100.00%


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); 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); } }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov9288.46%125.00%
david s. millerdavid s. miller87.69%125.00%
lorenzo colittilorenzo colitti21.92%125.00%
eric dumazeteric dumazet21.92%125.00%
Total104100.00%4100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
lorenzo colittilorenzo colitti18551.68%116.67%
vasiliy kulikovvasiliy kulikov16044.69%116.67%
eric dumazeteric dumazet92.51%350.00%
jane zhoujane zhou41.12%116.67%
Total358100.00%6100.00%


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)); }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov6880.00%120.00%
eric w. biedermaneric w. biederman1112.94%240.00%
americo wangamerico wang55.88%120.00%
eric dumazeteric dumazet11.18%120.00%
Total85100.00%5100.00%


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; 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(); 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; }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov11256.57%120.00%
eric w. biedermaneric w. biederman4120.71%240.00%
xiaoming wangxiaoming wang3115.66%120.00%
lorenzo colittilorenzo colitti147.07%120.00%
Total198100.00%5100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov46100.00%1100.00%
Total46100.00%1100.00%

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 ((net->ipv4.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 -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 (!(net->ipv6.sysctl.ip_nonlocal_bind || 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; }

Contributors

PersonTokensPropCommitsCommitProp
lorenzo colittilorenzo colitti36983.48%228.57%
vasiliy kulikovvasiliy kulikov4911.09%114.29%
hannes frederic sowahannes frederic sowa112.49%114.29%
tom herberttom herbert81.81%114.29%
vincent bernatvincent bernat40.90%114.29%
fengguang wufengguang wu10.23%114.29%
Total442100.00%7100.00%


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 } }

Contributors

PersonTokensPropCommitsCommitProp
lorenzo colittilorenzo colitti11297.39%133.33%
eric dumazeteric dumazet21.74%133.33%
fengguang wufengguang wu10.87%133.33%
Total115100.00%3100.00%


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 } }

Contributors

PersonTokensPropCommitsCommitProp
lorenzo colittilorenzo colitti10895.58%133.33%
eric dumazeteric dumazet43.54%133.33%
fengguang wufengguang wu10.88%133.33%
Total113100.00%3100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov15352.04%120.00%
lorenzo colittilorenzo colitti12040.82%120.00%
eric dumazeteric dumazet217.14%360.00%
Total294100.00%5100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
lorenzo colittilorenzo colitti2351.11%150.00%
vasiliy kulikovvasiliy kulikov2248.89%150.00%
Total45100.00%2100.00%

/* * 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