cregit-Linux how code gets into the kernel

Release 4.11 net/netfilter/ipvs/ip_vs_app.c

/*
 * ip_vs_app.c: Application module support for IPVS
 *
 * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
 *
 *              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.
 *
 * Most code here is taken from ip_masq_app.c in kernel 2.2. The difference
 * is that ip_vs_app module handles the reverse direction (incoming requests
 * and outgoing responses).
 *
 *              IP_MASQ_APP application masquerading module
 *
 * Author:      Juan Jose Ciarlante, <jjciarla@raiz.uncu.edu.ar>
 *
 */


#define KMSG_COMPONENT "IPVS"

#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/netfilter.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/protocol.h>
#include <net/tcp.h>
#include <linux/stat.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/mutex.h>

#include <net/ip_vs.h>


EXPORT_SYMBOL(register_ip_vs_app);

EXPORT_SYMBOL(unregister_ip_vs_app);

EXPORT_SYMBOL(register_ip_vs_app_inc);

static DEFINE_MUTEX(__ip_vs_app_mutex);

/*
 *      Get an ip_vs_app object
 */

static inline int ip_vs_app_get(struct ip_vs_app *app) { return try_module_get(app->module); }

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Wensong Zhang20100.00%1100.00%
Total20100.00%1100.00%


static inline void ip_vs_app_put(struct ip_vs_app *app) { module_put(app->module); }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang19100.00%1100.00%
Total19100.00%1100.00%


static void ip_vs_app_inc_destroy(struct ip_vs_app *inc) { kfree(inc->timeout_table); kfree(inc); }

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PersonTokensPropCommitsCommitProp
Julian Anastasov23100.00%1100.00%
Total23100.00%1100.00%


static void ip_vs_app_inc_rcu_free(struct rcu_head *head) { struct ip_vs_app *inc = container_of(head, struct ip_vs_app, rcu_head); ip_vs_app_inc_destroy(inc); }

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PersonTokensPropCommitsCommitProp
Julian Anastasov31100.00%1100.00%
Total31100.00%1100.00%

/* * Allocate/initialize app incarnation and register it in proto apps. */
static int ip_vs_app_inc_new(struct netns_ipvs *ipvs, struct ip_vs_app *app, __u16 proto, __u16 port) { struct ip_vs_protocol *pp; struct ip_vs_app *inc; int ret; if (!(pp = ip_vs_proto_get(proto))) return -EPROTONOSUPPORT; if (!pp->unregister_app) return -EOPNOTSUPP; inc = kmemdup(app, sizeof(*inc), GFP_KERNEL); if (!inc) return -ENOMEM; INIT_LIST_HEAD(&inc->p_list); INIT_LIST_HEAD(&inc->incs_list); inc->app = app; inc->port = htons(port); atomic_set(&inc->usecnt, 0); if (app->timeouts) { inc->timeout_table = ip_vs_create_timeout_table(app->timeouts, app->timeouts_size); if (!inc->timeout_table) { ret = -ENOMEM; goto out; } } ret = pp->register_app(ipvs, inc); if (ret) goto out; list_add(&inc->a_list, &app->incs_list); IP_VS_DBG(9, "%s App %s:%u registered\n", pp->name, inc->name, ntohs(inc->port)); return 0; out: ip_vs_app_inc_destroy(inc); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang21592.27%112.50%
Arnaldo Carvalho de Melo52.15%112.50%
Julian Anastasov52.15%225.00%
Hans Schillstrom41.72%112.50%
Eric W. Biedermann31.29%225.00%
Adrian Bunk10.43%112.50%
Total233100.00%8100.00%

/* * Release app incarnation */
static void ip_vs_app_inc_release(struct netns_ipvs *ipvs, struct ip_vs_app *inc) { struct ip_vs_protocol *pp; if (!(pp = ip_vs_proto_get(inc->protocol))) return; if (pp->unregister_app) pp->unregister_app(ipvs, inc); IP_VS_DBG(9, "%s App %s:%u unregistered\n", pp->name, inc->name, ntohs(inc->port)); list_del(&inc->a_list); call_rcu(&inc->rcu_head, ip_vs_app_inc_rcu_free); }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang7683.52%116.67%
Julian Anastasov88.79%233.33%
Hans Schillstrom44.40%116.67%
Eric W. Biedermann33.30%233.33%
Total91100.00%6100.00%

/* * Get reference to app inc (only called from softirq) * */
int ip_vs_app_inc_get(struct ip_vs_app *inc) { int result; result = ip_vs_app_get(inc->app); if (result) atomic_inc(&inc->usecnt); return result; }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang3286.49%150.00%
Julian Anastasov513.51%150.00%
Total37100.00%2100.00%

/* * Put the app inc (only called from timer or net softirq) */
void ip_vs_app_inc_put(struct ip_vs_app *inc) { atomic_dec(&inc->usecnt); ip_vs_app_put(inc->app); }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang2080.00%150.00%
Julian Anastasov520.00%150.00%
Total25100.00%2100.00%

/* * Register an application incarnation in protocol applications */
int register_ip_vs_app_inc(struct netns_ipvs *ipvs, struct ip_vs_app *app, __u16 proto, __u16 port) { int result; mutex_lock(&__ip_vs_app_mutex); result = ip_vs_app_inc_new(ipvs, app, proto, port); mutex_unlock(&__ip_vs_app_mutex); return result; }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang4178.85%116.67%
Hans Schillstrom47.69%116.67%
Eric W. Biedermann35.77%233.33%
Simon Horman23.85%116.67%
Ingo Molnar23.85%116.67%
Total52100.00%6100.00%

/* Register application for netns */
struct ip_vs_app *register_ip_vs_app(struct netns_ipvs *ipvs, struct ip_vs_app *app) { struct ip_vs_app *a; int err = 0; mutex_lock(&__ip_vs_app_mutex); list_for_each_entry(a, &ipvs->app_list, a_list) { if (!strcmp(app->name, a->name)) { err = -EEXIST; goto out_unlock; } } a = kmemdup(app, sizeof(*app), GFP_KERNEL); if (!a) { err = -ENOMEM; goto out_unlock; } INIT_LIST_HEAD(&a->incs_list); list_add(&a->a_list, &ipvs->app_list); /* increase the module use count */ ip_vs_use_count_inc(); out_unlock: mutex_unlock(&__ip_vs_app_mutex); return err ? ERR_PTR(err) : a; }

Contributors

PersonTokensPropCommitsCommitProp
Julian Anastasov9970.71%116.67%
Wensong Zhang2820.00%116.67%
Hans Schillstrom75.00%116.67%
Ingo Molnar21.43%116.67%
Eric W. Biedermann21.43%116.67%
Simon Horman21.43%116.67%
Total140100.00%6100.00%

/* * ip_vs_app unregistration routine * We are sure there are no app incarnations attached to services * Caller should use synchronize_rcu() or rcu_barrier() */
void unregister_ip_vs_app(struct netns_ipvs *ipvs, struct ip_vs_app *app) { struct ip_vs_app *a, *anxt, *inc, *nxt; mutex_lock(&__ip_vs_app_mutex); list_for_each_entry_safe(a, anxt, &ipvs->app_list, a_list) { if (app && strcmp(app->name, a->name)) continue; list_for_each_entry_safe(inc, nxt, &a->incs_list, a_list) { ip_vs_app_inc_release(ipvs, inc); } list_del(&a->a_list); kfree(a); /* decrease the module use count */ ip_vs_use_count_dec(); } mutex_unlock(&__ip_vs_app_mutex); }

Contributors

PersonTokensPropCommitsCommitProp
Julian Anastasov4441.90%111.11%
Wensong Zhang3735.24%111.11%
Stephen Hemminger1514.29%222.22%
Hans Schillstrom43.81%111.11%
Eric W. Biedermann32.86%222.22%
Simon Horman10.95%111.11%
Ingo Molnar10.95%111.11%
Total105100.00%9100.00%

/* * Bind ip_vs_conn to its ip_vs_app (called by cp constructor) */
int ip_vs_bind_app(struct ip_vs_conn *cp, struct ip_vs_protocol *pp) { return pp->app_conn_bind(cp); }

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Wensong Zhang23100.00%1100.00%
Total23100.00%1100.00%

/* * Unbind cp from application incarnation (called by cp destructor) */
void ip_vs_unbind_app(struct ip_vs_conn *cp) { struct ip_vs_app *inc = cp->app; if (!inc) return; if (inc->unbind_conn) inc->unbind_conn(inc, cp); if (inc->done_conn) inc->done_conn(inc, cp); ip_vs_app_inc_put(inc); cp->app = NULL; }

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PersonTokensPropCommitsCommitProp
Wensong Zhang66100.00%1100.00%
Total66100.00%1100.00%

/* * Fixes th->seq based on ip_vs_seq info. */
static inline void vs_fix_seq(const struct ip_vs_seq *vseq, struct tcphdr *th) { __u32 seq = ntohl(th->seq); /* * Adjust seq with delta-offset for all packets after * the most recent resized pkt seq and with previous_delta offset * for all packets before most recent resized pkt seq. */ if (vseq->delta || vseq->previous_delta) { if(after(seq, vseq->init_seq)) { th->seq = htonl(seq + vseq->delta); IP_VS_DBG(9, "%s(): added delta (%d) to seq\n", __func__, vseq->delta); } else { th->seq = htonl(seq + vseq->previous_delta); IP_VS_DBG(9, "%s(): added previous_delta (%d) to seq\n", __func__, vseq->previous_delta); } } }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang10394.50%150.00%
Hannes Eder65.50%150.00%
Total109100.00%2100.00%

/* * Fixes th->ack_seq based on ip_vs_seq info. */
static inline void vs_fix_ack_seq(const struct ip_vs_seq *vseq, struct tcphdr *th) { __u32 ack_seq = ntohl(th->ack_seq); /* * Adjust ack_seq with delta-offset for * the packets AFTER most recent resized pkt has caused a shift * for packets before most recent resized pkt, use previous_delta */ if (vseq->delta || vseq->previous_delta) { /* since ack_seq is the number of octet that is expected to receive next, so compare it with init_seq+delta */ if(after(ack_seq, vseq->init_seq+vseq->delta)) { th->ack_seq = htonl(ack_seq - vseq->delta); IP_VS_DBG(9, "%s(): subtracted delta " "(%d) from ack_seq\n", __func__, vseq->delta); } else { th->ack_seq = htonl(ack_seq - vseq->previous_delta); IP_VS_DBG(9, "%s(): subtracted " "previous_delta (%d) from ack_seq\n", __func__, vseq->previous_delta); } } }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang11094.83%150.00%
Hannes Eder65.17%150.00%
Total116100.00%2100.00%

/* * Updates ip_vs_seq if pkt has been resized * Assumes already checked proto==IPPROTO_TCP and diff!=0. */
static inline void vs_seq_update(struct ip_vs_conn *cp, struct ip_vs_seq *vseq, unsigned int flag, __u32 seq, int diff) { /* spinlock is to keep updating cp->flags atomic */ spin_lock_bh(&cp->lock); if (!(cp->flags & flag) || after(seq, vseq->init_seq)) { vseq->previous_delta = vseq->delta; vseq->delta += diff; vseq->init_seq = seq; cp->flags |= flag; } spin_unlock_bh(&cp->lock); }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang8996.74%133.33%
Julian Anastasov22.17%133.33%
Eric Dumazet11.09%133.33%
Total92100.00%3100.00%


static inline int app_tcp_pkt_out(struct ip_vs_conn *cp, struct sk_buff *skb, struct ip_vs_app *app) { int diff; const unsigned int tcp_offset = ip_hdrlen(skb); struct tcphdr *th; __u32 seq; if (!skb_make_writable(skb, tcp_offset + sizeof(*th))) return 0; th = (struct tcphdr *)(skb_network_header(skb) + tcp_offset); /* * Remember seq number in case this pkt gets resized */ seq = ntohl(th->seq); /* * Fix seq stuff if flagged as so. */ if (cp->flags & IP_VS_CONN_F_OUT_SEQ) vs_fix_seq(&cp->out_seq, th); if (cp->flags & IP_VS_CONN_F_IN_SEQ) vs_fix_ack_seq(&cp->in_seq, th); /* * Call private output hook function */ if (app->pkt_out == NULL) return 1; if (!app->pkt_out(app, cp, skb, &diff)) return 0; /* * Update ip_vs seq stuff if len has changed. */ if (diff != 0) vs_seq_update(cp, &cp->out_seq, IP_VS_CONN_F_OUT_SEQ, seq, diff); return 1; }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang13573.77%116.67%
Julian Anastasov3519.13%116.67%
Arnaldo Carvalho de Melo73.83%233.33%
Herbert Xu63.28%233.33%
Total183100.00%6100.00%

/* * Output pkt hook. Will call bound ip_vs_app specific function * called by ipvs packet handler, assumes previously checked cp!=NULL * returns false if it can't handle packet (oom) */
int ip_vs_app_pkt_out(struct ip_vs_conn *cp, struct sk_buff *skb) { struct ip_vs_app *app; /* * check if application module is bound to * this ip_vs_conn. */ if ((app = cp->app) == NULL) return 1; /* TCP is complicated */ if (cp->protocol == IPPROTO_TCP) return app_tcp_pkt_out(cp, skb, app); /* * Call private output hook function */ if (app->pkt_out == NULL) return 1; return app->pkt_out(app, cp, skb, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Julian Anastasov4656.79%133.33%
Wensong Zhang3239.51%133.33%
Herbert Xu33.70%133.33%
Total81100.00%3100.00%


static inline int app_tcp_pkt_in(struct ip_vs_conn *cp, struct sk_buff *skb, struct ip_vs_app *app) { int diff; const unsigned int tcp_offset = ip_hdrlen(skb); struct tcphdr *th; __u32 seq; if (!skb_make_writable(skb, tcp_offset + sizeof(*th))) return 0; th = (struct tcphdr *)(skb_network_header(skb) + tcp_offset); /* * Remember seq number in case this pkt gets resized */ seq = ntohl(th->seq); /* * Fix seq stuff if flagged as so. */ if (cp->flags & IP_VS_CONN_F_IN_SEQ) vs_fix_seq(&cp->in_seq, th); if (cp->flags & IP_VS_CONN_F_OUT_SEQ) vs_fix_ack_seq(&cp->out_seq, th); /* * Call private input hook function */ if (app->pkt_in == NULL) return 1; if (!app->pkt_in(app, cp, skb, &diff)) return 0; /* * Update ip_vs seq stuff if len has changed. */ if (diff != 0) vs_seq_update(cp, &cp->in_seq, IP_VS_CONN_F_IN_SEQ, seq, diff); return 1; }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang10155.19%116.67%
Julian Anastasov6937.70%116.67%
Arnaldo Carvalho de Melo73.83%233.33%
Herbert Xu63.28%233.33%
Total183100.00%6100.00%

/* * Input pkt hook. Will call bound ip_vs_app specific function * called by ipvs packet handler, assumes previously checked cp!=NULL. * returns false if can't handle packet (oom). */
int ip_vs_app_pkt_in(struct ip_vs_conn *cp, struct sk_buff *skb) { struct ip_vs_app *app; /* * check if application module is bound to * this ip_vs_conn. */ if ((app = cp->app) == NULL) return 1; /* TCP is complicated */ if (cp->protocol == IPPROTO_TCP) return app_tcp_pkt_in(cp, skb, app); /* * Call private input hook function */ if (app->pkt_in == NULL) return 1; return app->pkt_in(app, cp, skb, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Julian Anastasov7693.83%133.33%
Herbert Xu33.70%133.33%
Wensong Zhang22.47%133.33%
Total81100.00%3100.00%

#ifdef CONFIG_PROC_FS /* * /proc/net/ip_vs_app entry function */
static struct ip_vs_app *ip_vs_app_idx(struct netns_ipvs *ipvs, loff_t pos) { struct ip_vs_app *app, *inc; list_for_each_entry(app, &ipvs->app_list, a_list) { list_for_each_entry(inc, &app->incs_list, a_list) { if (pos-- == 0) return inc; } } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger3764.91%250.00%
Wensong Zhang1424.56%125.00%
Hans Schillstrom610.53%125.00%
Total57100.00%4100.00%


static void *ip_vs_app_seq_start(struct seq_file *seq, loff_t *pos) { struct net *net = seq_file_net(seq); struct netns_ipvs *ipvs = net_ipvs(net); mutex_lock(&__ip_vs_app_mutex); return *pos ? ip_vs_app_idx(ipvs, *pos - 1) : SEQ_START_TOKEN; }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger2950.00%120.00%
Hans Schillstrom2237.93%120.00%
Wensong Zhang58.62%120.00%
Ingo Molnar11.72%120.00%
Simon Horman11.72%120.00%
Total58100.00%5100.00%


static void *ip_vs_app_seq_next(struct seq_file *seq, void *v, loff_t *pos) { struct ip_vs_app *inc, *app; struct list_head *e; struct net *net = seq_file_net(seq); struct netns_ipvs *ipvs = net_ipvs(net); ++*pos; if (v == SEQ_START_TOKEN) return ip_vs_app_idx(ipvs, 0); inc = v; app = inc->app; if ((e = inc->a_list.next) != &app->incs_list) return list_entry(e, struct ip_vs_app, a_list); /* go on to next application */ for (e = app->a_list.next; e != &ipvs->app_list; e = e->next) { app = list_entry(e, struct ip_vs_app, a_list); list_for_each_entry(inc, &app->incs_list, a_list) { return inc; } } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger11872.39%250.00%
Hans Schillstrom2515.34%125.00%
Wensong Zhang2012.27%125.00%
Total163100.00%4100.00%


static void ip_vs_app_seq_stop(struct seq_file *seq, void *v) { mutex_unlock(&__ip_vs_app_mutex); }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger1885.71%125.00%
Wensong Zhang14.76%125.00%
Simon Horman14.76%125.00%
Ingo Molnar14.76%125.00%
Total21100.00%4100.00%


static int ip_vs_app_seq_show(struct seq_file *seq, void *v) { if (v == SEQ_START_TOKEN) seq_puts(seq, "prot port usecnt name\n"); else { const struct ip_vs_app *inc = v; seq_printf(seq, "%-3s %-7u %-6d %-17s\n", ip_vs_proto_name(inc->protocol), ntohs(inc->port), atomic_read(&inc->usecnt), inc->name); } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger4053.33%150.00%
Wensong Zhang3546.67%150.00%
Total75100.00%2100.00%

static const struct seq_operations ip_vs_app_seq_ops = { .start = ip_vs_app_seq_start, .next = ip_vs_app_seq_next, .stop = ip_vs_app_seq_stop, .show = ip_vs_app_seq_show, };
static int ip_vs_app_open(struct inode *inode, struct file *file) { return seq_open_net(inode, file, &ip_vs_app_seq_ops, sizeof(struct seq_net_private)); }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger2163.64%133.33%
Hans Schillstrom927.27%133.33%
Wensong Zhang39.09%133.33%
Total33100.00%3100.00%

static const struct file_operations ip_vs_app_fops = { .owner = THIS_MODULE, .open = ip_vs_app_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release_net, }; #endif
int __net_init ip_vs_app_net_init(struct netns_ipvs *ipvs) { INIT_LIST_HEAD(&ipvs->app_list); proc_create("ip_vs_app", 0, ipvs->net->proc_net, &ip_vs_app_fops); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang1436.84%112.50%
Hans Schillstrom1334.21%337.50%
Gao Feng513.16%112.50%
Eric W. Biedermann25.26%112.50%
Stephen Hemminger25.26%112.50%
Arnd Bergmann25.26%112.50%
Total38100.00%8100.00%


void __net_exit ip_vs_app_net_cleanup(struct netns_ipvs *ipvs) { unregister_ip_vs_app(ipvs, NULL /* all */); remove_proc_entry("ip_vs_app", ipvs->net->proc_net); }

Contributors

PersonTokensPropCommitsCommitProp
Hans Schillstrom1343.33%228.57%
Eric W. Biedermann516.67%228.57%
Gao Feng516.67%114.29%
Julian Anastasov516.67%114.29%
Arnd Bergmann26.67%114.29%
Total30100.00%7100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Wensong Zhang130055.44%12.56%
Julian Anastasov45719.49%512.82%
Stephen Hemminger34114.54%37.69%
Hans Schillstrom1124.78%410.26%
Eric W. Biedermann241.02%717.95%
Hannes Eder230.98%25.13%
Arnaldo Carvalho de Melo220.94%410.26%
Herbert Xu210.90%25.13%
Simon Horman130.55%12.56%
Gao Feng100.43%25.13%
Ingo Molnar100.43%12.56%
Arnd Bergmann40.17%12.56%
Tejun Heo30.13%12.56%
Adrian Bunk20.09%25.13%
Philippe De Muyter10.04%12.56%
Arjan van de Ven10.04%12.56%
Eric Dumazet10.04%12.56%
Total2345100.00%39100.00%
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