cregit-Linux how code gets into the kernel

Release 4.15 net/ipv4/gre_demux.c

Directory: net/ipv4
/*
 *      GRE over IPv4 demultiplexer driver
 *
 *      Authors: Dmitry Kozlov (xeb@mail.ru)
 *
 *      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.
 *
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/if.h>
#include <linux/icmp.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/netdevice.h>
#include <linux/if_tunnel.h>
#include <linux/spinlock.h>
#include <net/protocol.h>
#include <net/gre.h>

#include <net/icmp.h>
#include <net/route.h>
#include <net/xfrm.h>


static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly;


int gre_add_protocol(const struct gre_protocol *proto, u8 version) { if (version >= GREPROTO_MAX) return -EINVAL; return (cmpxchg((const struct gre_protocol **)&gre_proto[version], NULL, proto) == NULL) ? 0 : -EBUSY; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Kozlov3259.26%150.00%
Pravin B Shelar2240.74%150.00%
Total54100.00%2100.00%

EXPORT_SYMBOL_GPL(gre_add_protocol);
int gre_del_protocol(const struct gre_protocol *proto, u8 version) { int ret; if (version >= GREPROTO_MAX) return -EINVAL; ret = (cmpxchg((const struct gre_protocol **)&gre_proto[version], proto, NULL) == proto) ? 0 : -EBUSY; if (ret) return ret; synchronize_rcu(); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Pravin B Shelar5678.87%375.00%
Dmitry Kozlov1521.13%125.00%
Total71100.00%4100.00%

EXPORT_SYMBOL_GPL(gre_del_protocol); /* Fills in tpi and returns header length to be pulled. */
int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, bool *csum_err, __be16 proto, int nhs) { const struct gre_base_hdr *greh; __be32 *options; int hdr_len; if (unlikely(!pskb_may_pull(skb, nhs + sizeof(struct gre_base_hdr)))) return -EINVAL; greh = (struct gre_base_hdr *)(skb->data + nhs); if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING))) return -EINVAL; tpi->flags = gre_flags_to_tnl_flags(greh->flags); hdr_len = gre_calc_hlen(tpi->flags); if (!pskb_may_pull(skb, nhs + hdr_len)) return -EINVAL; greh = (struct gre_base_hdr *)(skb->data + nhs); tpi->proto = greh->protocol; options = (__be32 *)(greh + 1); if (greh->flags & GRE_CSUM) { if (skb_checksum_simple_validate(skb)) { *csum_err = true; return -EINVAL; } skb_checksum_try_convert(skb, IPPROTO_GRE, 0, null_compute_pseudo); options++; } if (greh->flags & GRE_KEY) { tpi->key = *options; options++; } else { tpi->key = 0; } if (unlikely(greh->flags & GRE_SEQ)) { tpi->seq = *options; options++; } else { tpi->seq = 0; } /* WCCP version 1 and 2 protocol decoding. * - Change protocol to IPv4/IPv6 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header */ if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) { tpi->proto = proto; if ((*(u8 *)options & 0xF0) != 0x40) hdr_len += 4; } tpi->hdr_len = hdr_len; return hdr_len; }

Contributors

PersonTokensPropCommitsCommitProp
Tom Herbert29290.40%120.00%
Eric Dumazet257.74%240.00%
Haishuang Yan51.55%120.00%
Jiri Benc10.31%120.00%
Total323100.00%5100.00%

EXPORT_SYMBOL(gre_parse_header);
static int gre_rcv(struct sk_buff *skb) { const struct gre_protocol *proto; u8 ver; int ret; if (!pskb_may_pull(skb, 12)) goto drop; ver = skb->data[1]&0x7f; if (ver >= GREPROTO_MAX) goto drop; rcu_read_lock(); proto = rcu_dereference(gre_proto[ver]); if (!proto || !proto->handler) goto drop_unlock; ret = proto->handler(skb); rcu_read_unlock(); return ret; drop_unlock: rcu_read_unlock(); drop: kfree_skb(skb); return NET_RX_DROP; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Kozlov112100.00%1100.00%
Total112100.00%1100.00%


static void gre_err(struct sk_buff *skb, u32 info) { const struct gre_protocol *proto; const struct iphdr *iph = (const struct iphdr *)skb->data; u8 ver = skb->data[(iph->ihl<<2) + 1]&0x7f; if (ver >= GREPROTO_MAX) return; rcu_read_lock(); proto = rcu_dereference(gre_proto[ver]); if (proto && proto->err_handler) proto->err_handler(skb, info); rcu_read_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Kozlov96100.00%2100.00%
Total96100.00%2100.00%

static const struct net_protocol net_gre_protocol = { .handler = gre_rcv, .err_handler = gre_err, .netns_ok = 1, };
static int __init gre_init(void) { pr_info("GRE over IPv4 demultiplexor driver\n"); if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) { pr_err("can't add protocol\n"); return -EAGAIN; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Kozlov2972.50%125.00%
Pravin B Shelar922.50%250.00%
Joe Perches25.00%125.00%
Total40100.00%4100.00%


static void __exit gre_exit(void) { inet_del_protocol(&net_gre_protocol, IPPROTO_GRE); }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Kozlov17100.00%1100.00%
Total17100.00%1100.00%

module_init(gre_init); module_exit(gre_exit); MODULE_DESCRIPTION("GRE over IPv4 demultiplexer driver"); MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
Dmitry Kozlov39546.75%214.29%
Tom Herbert29735.15%17.14%
Pravin B Shelar11013.02%428.57%
Eric Dumazet263.08%321.43%
Joe Perches91.07%17.14%
Haishuang Yan50.59%17.14%
Jiri Benc20.24%17.14%
Stephen Hemminger10.12%17.14%
Total845100.00%14100.00%
Directory: net/ipv4
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.