cregit-Linux how code gets into the kernel

Release 4.8 net/ipv4/sysctl_net_ipv4.c

Directory: net/ipv4
/*
 * sysctl_net_ipv4.c: sysctl interface to net IPV4 subsystem.
 *
 * Begun April 1, 1996, Mike Shaver.
 * Added /proc/sys/net/ipv4 directory entry (empty =) ). [MS]
 */

#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sysctl.h>
#include <linux/igmp.h>
#include <linux/inetdevice.h>
#include <linux/seqlock.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/nsproxy.h>
#include <linux/swap.h>
#include <net/snmp.h>
#include <net/icmp.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/cipso_ipv4.h>
#include <net/inet_frag.h>
#include <net/ping.h>


static int zero;

static int one = 1;

static int four = 4;

static int thousand = 1000;

static int gso_max_segs = GSO_MAX_SEGS;

static int tcp_retr1_max = 255;

static int ip_local_port_range_min[] = { 1, 1 };

static int ip_local_port_range_max[] = { 65535, 65535 };

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 tcp_syn_retries_min = 1;

static int tcp_syn_retries_max = MAX_TCP_SYNCNT;

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(struct net *net, int range[2]) { bool same_parity = !((range[0] ^ range[1]) & 1); write_seqlock_bh(&net->ipv4.ip_local_ports.lock); if (same_parity && !net->ipv4.ip_local_ports.warned) { net->ipv4.ip_local_ports.warned = true; pr_err_ratelimited("ip_local_port_range: prefer different parity for start/end values.\n"); } net->ipv4.ip_local_ports.range[0] = range[0]; net->ipv4.ip_local_ports.range[1] = range[1]; write_sequnlock_bh(&net->ipv4.ip_local_ports.lock); }

Contributors

PersonTokensPropCommitsCommitProp
eric dumazeteric dumazet5847.15%233.33%
stephen hemmingerstephen hemminger3830.89%116.67%
eric w. biedermaneric w. biederman2117.07%116.67%
americo wangamerico wang64.88%233.33%
Total123100.00%6100.00%

/* Validate changes from /proc interface. */
static int ipv4_local_port_range(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct net *net = container_of(table->data, struct net, ipv4.ip_local_ports.range); int ret; int range[2]; struct ctl_table tmp = { .data = &range, .maxlen = sizeof(range), .mode = table->mode, .extra1 = &ip_local_port_range_min, .extra2 = &ip_local_port_range_max, }; inet_get_local_port_range(net, &range[0], &range[1]); ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); if (write && ret == 0) { if (range[1] < range[0]) ret = -EINVAL; else set_local_port_range(net, range); } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
stephen hemmingerstephen hemminger12474.25%116.67%
eric w. biedermaneric w. biederman3118.56%116.67%
eric dumazeteric dumazet84.79%116.67%
joe perchesjoe perches21.20%116.67%
americo wangamerico wang10.60%116.67%
anton arapovanton arapov10.60%116.67%
Total167100.00%6100.00%


static void inet_get_ping_group_range_table(struct ctl_table *table, kgid_t *low, kgid_t *high) { kgid_t *data = table->data; struct net *net = container_of(table->data, struct net, ipv4.ping_group_range.range); unsigned int seq; do { seq = read_seqbegin(&net->ipv4.ip_local_ports.lock); *low = data[0]; *high = data[1]; } while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq)); }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov6664.71%114.29%
eric w. biedermaneric w. biederman2928.43%228.57%
americo wangamerico wang54.90%228.57%
eric dumazeteric dumazet21.96%228.57%
Total102100.00%7100.00%

/* Update system visible IP port range */
static void set_ping_group_range(struct ctl_table *table, kgid_t low, kgid_t high) { kgid_t *data = table->data; struct net *net = container_of(table->data, struct net, ipv4.ping_group_range.range); write_seqlock(&net->ipv4.ip_local_ports.lock); data[0] = low; data[1] = high; write_sequnlock(&net->ipv4.ip_local_ports.lock); }

Contributors

PersonTokensPropCommitsCommitProp
vasiliy kulikovvasiliy kulikov4553.57%120.00%
eric w. biedermaneric w. biederman3440.48%240.00%
americo wangamerico wang55.95%240.00%
Total84100.00%5100.00%

/* Validate changes from /proc interface. */
static int ipv4_ping_group_range(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct user_namespace *user_ns = current_user_ns(); int ret; gid_t urange[2]; kgid_t low, high; struct ctl_table tmp = { .data = &urange, .maxlen = sizeof(urange), .mode = table->mode, .extra1 = &ip_ping_group_range_min, .extra2 = &ip_ping_group_range_max, }; inet_get_ping_group_range_table(table, &low, &high); urange[0] = from_kgid_munged(user_ns, low); urange[1] = from_kgid_munged(user_ns, high); ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); if (write && ret == 0) { low = make_kgid(user_ns, urange[0]); high = make_kgid(user_ns, urange[1]); if (!gid_valid(low) || !gid_valid(high) || (urange[1] < urange[0]) || gid_lt(high, low)) { low = make_kgid(&init_user_ns, 1); high = make_kgid(&init_user_ns, 0); } set_ping_group_range(table, low, high); } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
eric w. biedermaneric w. biederman12752.92%133.33%
vasiliy kulikovvasiliy kulikov11146.25%133.33%
joe perchesjoe perches20.83%133.33%
Total240100.00%3100.00%


static int proc_tcp_congestion_control(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { char val[TCP_CA_NAME_MAX]; struct ctl_table tbl = { .data = val, .maxlen = TCP_CA_NAME_MAX, }; int ret; tcp_get_default_congestion_control(val); ret = proc_dostring(&tbl, write, buffer, lenp, ppos); if (write && ret == 0) ret = tcp_set_default_congestion_control(val); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
stephen hemmingerstephen hemminger8997.80%150.00%
joe perchesjoe perches22.20%150.00%
Total91100.00%2100.00%


static int proc_tcp_available_congestion_control(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, }; int ret; tbl.data = kmalloc(tbl.maxlen, GFP_USER); if (!tbl.data) return -ENOMEM; tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX); ret = proc_dostring(&tbl, write, buffer, lenp, ppos); kfree(tbl.data); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
stephen hemmingerstephen hemminger9898.00%150.00%
joe perchesjoe perches22.00%150.00%
Total100100.00%2100.00%


static int proc_allowed_congestion_control(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX }; int ret; tbl.data = kmalloc(tbl.maxlen, GFP_USER); if (!tbl.data) return -ENOMEM; tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen); ret = proc_dostring(&tbl, write, buffer, lenp, ppos); if (write && ret == 0) ret = tcp_set_allowed_congestion_control(tbl.data); kfree(tbl.data); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
stephen hemmingerstephen hemminger11798.32%150.00%
joe perchesjoe perches21.68%150.00%
Total119100.00%2100.00%


static int proc_tcp_fastopen_key(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table tbl = { .maxlen = (TCP_FASTOPEN_KEY_LENGTH * 2 + 10) }; struct tcp_fastopen_context *ctxt; int ret; u32 user_key[4]; /* 16 bytes, matching TCP_FASTOPEN_KEY_LENGTH */ tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL); if (!tbl.data) return -ENOMEM; rcu_read_lock(); ctxt = rcu_dereference(tcp_fastopen_ctx); if (ctxt) memcpy(user_key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH); else memset(user_key, 0, sizeof(user_key)); rcu_read_unlock(); snprintf(tbl.data, tbl.maxlen, "%08x-%08x-%08x-%08x", user_key[0], user_key[1], user_key[2], user_key[3]); ret = proc_dostring(&tbl, write, buffer, lenp, ppos); if (write && ret == 0) { if (sscanf(tbl.data, "%x-%x-%x-%x", user_key, user_key + 1, user_key + 2, user_key + 3) != 4) { ret = -EINVAL; goto bad_key; } /* Generate a dummy secret but don't publish it. This * is needed so we don't regenerate a new key on the * first invocation of tcp_fastopen_cookie_gen */ tcp_fastopen_init_key_once(false); tcp_fastopen_reset_cipher(user_key, TCP_FASTOPEN_KEY_LENGTH); } bad_key: pr_debug("proc FO key set 0x%x-%x-%x-%x <- 0x%s: %u\n", user_key[0], user_key[1], user_key[2], user_key[3], (char *)tbl.data, ret); kfree(tbl.data); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
jerry chujerry chu25892.14%120.00%
alan coxalan cox134.64%120.00%
hannes frederic sowahannes frederic sowa62.14%120.00%
joe perchesjoe perches20.71%120.00%
stephen hemmingerstephen hemminger10.36%120.00%
Total280100.00%5100.00%

static struct ctl_table ipv4_table[] = { { .procname = "tcp_timestamps", .data = &sysctl_tcp_timestamps, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_window_scaling", .data = &sysctl_tcp_window_scaling, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_sack", .data = &sysctl_tcp_sack, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_retrans_collapse", .data = &sysctl_tcp_retrans_collapse, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_max_orphans", .data = &sysctl_tcp_max_orphans, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_max_tw_buckets", .data = &tcp_death_row.sysctl_max_tw_buckets, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_fastopen", .data = &sysctl_tcp_fastopen, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "tcp_fastopen_key", .mode = 0600, .maxlen = ((TCP_FASTOPEN_KEY_LENGTH * 2) + 10), .proc_handler = proc_tcp_fastopen_key, }, { .procname = "tcp_tw_recycle", .data = &tcp_death_row.sysctl_tw_recycle, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_abort_on_overflow", .data = &sysctl_tcp_abort_on_overflow, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_stdurg", .data = &sysctl_tcp_stdurg, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_rfc1337", .data = &sysctl_tcp_rfc1337, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_max_syn_backlog", .data = &sysctl_max_syn_backlog, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "inet_peer_threshold", .data = &inet_peer_threshold, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "inet_peer_minttl", .data = &inet_peer_minttl, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .procname = "inet_peer_maxttl", .data = &inet_peer_maxttl, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .procname = "tcp_fack", .data = &sysctl_tcp_fack, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_recovery", .data = &sysctl_tcp_recovery, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "tcp_max_reordering", .data = &sysctl_tcp_max_reordering, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_dsack", .data = &sysctl_tcp_dsack, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_mem", .maxlen = sizeof(sysctl_tcp_mem), .data = &sysctl_tcp_mem, .mode = 0644, .proc_handler = proc_doulongvec_minmax, }, { .procname = "tcp_wmem", .data = &sysctl_tcp_wmem, .maxlen = sizeof(sysctl_tcp_wmem), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &one, }, { .procname = "tcp_rmem", .data = &sysctl_tcp_rmem, .maxlen = sizeof(sysctl_tcp_rmem), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &one, }, { .procname = "tcp_app_win", .data = &sysctl_tcp_app_win, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_adv_win_scale", .data = &sysctl_tcp_adv_win_scale, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &tcp_adv_win_scale_min, .extra2 = &tcp_adv_win_scale_max, }, { .procname = "tcp_tw_reuse", .data = &sysctl_tcp_tw_reuse, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_frto", .data = &sysctl_tcp_frto, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_min_rtt_wlen", .data = &sysctl_tcp_min_rtt_wlen, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_low_latency", .data = &sysctl_tcp_low_latency, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_no_metrics_save", .data = &sysctl_tcp_nometrics_save, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "tcp_moderate_rcvbuf", .data = &sysctl_tcp_moderate_rcvbuf, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "tcp_tso_win_divisor", .data = &sysctl_tcp_tso_win_divisor, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "tcp_congestion_control", .mode = 0644, .maxlen = TCP_CA_NAME_MAX, .proc_handler = proc_tcp_congestion_control, }, { .procname = "tcp_workaround_signed_windows", .data = &sysctl_tcp_workaround_signed_windows, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_limit_output_bytes", .data = &sysctl_tcp_limit_output_bytes, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_challenge_ack_limit", .data = &sysctl_tcp_challenge_ack_limit, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_slow_start_after_idle", .data = &sysctl_tcp_slow_start_after_idle, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, #ifdef CONFIG_NETLABEL { .procname = "cipso_cache_enable", .data = &cipso_v4_cache_enabled, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "cipso_cache_bucket_size", .data = &cipso_v4_cache_bucketsize, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "cipso_rbm_optfmt", .data = &cipso_v4_rbm_optfmt, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "cipso_rbm_strictvalid", .data = &cipso_v4_rbm_strictvalid, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif /* CONFIG_NETLABEL */ { .procname = "tcp_available_congestion_control", .maxlen = TCP_CA_BUF_MAX, .mode = 0444, .proc_handler = proc_tcp_available_congestion_control, }, { .procname = "tcp_allowed_congestion_control", .maxlen = TCP_CA_BUF_MAX, .mode = 0644, .proc_handler = proc_allowed_congestion_control, }, { .procname = "tcp_thin_linear_timeouts", .data = &sysctl_tcp_thin_linear_timeouts, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_thin_dupack", .data = &sysctl_tcp_thin_dupack, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_early_retrans", .data = &sysctl_tcp_early_retrans, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &four, }, { .procname = "tcp_min_tso_segs", .data = &sysctl_tcp_min_tso_segs, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &one, .extra2 = &gso_max_segs, }, { .procname = "tcp_pacing_ss_ratio", .data =