/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int zero; static int one = 1; static int four = 4; 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]) { write_seqlock(&net->ipv4.sysctl_local_ports.lock); net->ipv4.sysctl_local_ports.range[0] = range[0]; net->ipv4.sysctl_local_ports.range[1] = range[1]; write_sequnlock(&net->ipv4.sysctl_local_ports.lock); } /* 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.sysctl_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; } 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.sysctl_ping_group_range); unsigned int seq; do { seq = read_seqbegin(&net->ipv4.sysctl_local_ports.lock); *low = data[0]; *high = data[1]; } while (read_seqretry(&net->ipv4.sysctl_local_ports.lock, seq)); } /* 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.sysctl_ping_group_range); write_seqlock(&net->ipv4.sysctl_local_ports.lock); data[0] = low; data[1] = high; write_sequnlock(&net->ipv4.sysctl_local_ports.lock); } /* 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; } 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; } 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; } 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; } 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; } 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 = "ip_default_ttl", .data = &sysctl_ip_default_ttl, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &ip_ttl_min, .extra2 = &ip_ttl_max, }, { .procname = "ip_no_pmtu_disc", .data = &ipv4_config.no_pmtu_disc, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "ip_nonlocal_bind", .data = &sysctl_ip_nonlocal_bind, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_syn_retries", .data = &sysctl_tcp_syn_retries, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &tcp_syn_retries_min, .extra2 = &tcp_syn_retries_max }, { .procname = "tcp_synack_retries", .data = &sysctl_tcp_synack_retries, .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 = "ip_early_demux", .data = &sysctl_ip_early_demux, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "ip_dynaddr", .data = &sysctl_ip_dynaddr, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_keepalive_time", .data = &sysctl_tcp_keepalive_time, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .procname = "tcp_keepalive_probes", .data = &sysctl_tcp_keepalive_probes, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_keepalive_intvl", .data = &sysctl_tcp_keepalive_intvl, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .procname = "tcp_retries1", .data = &sysctl_tcp_retries1, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra2 = &tcp_retr1_max }, { .procname = "tcp_retries2", .data = &sysctl_tcp_retries2, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_fin_timeout", .data = &sysctl_tcp_fin_timeout, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, #ifdef CONFIG_SYN_COOKIES { .procname = "tcp_syncookies", .data = &sysctl_tcp_syncookies, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, #endif { .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 = "ip_local_reserved_ports", .data = NULL, /* initialized in sysctl_ipv4_init */ .maxlen = 65536, .mode = 0644, .proc_handler = proc_do_large_bitmap, }, { .procname = "igmp_max_memberships", .data = &sysctl_igmp_max_memberships, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "igmp_max_msf", .data = &sysctl_igmp_max_msf, .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_orphan_retries", .data = &sysctl_tcp_orphan_retries, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_fack", .data = &sysctl_tcp_fack, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tcp_reordering", .data = &sysctl_tcp_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_notsent_lowat", .data = &sysctl_tcp_notsent_lowat, .maxlen = sizeof(sysctl_tcp_notsent_lowat), .mode = 0644, .proc_handler = proc_dointvec, }, { .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_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_mtu_probing", .data = &sysctl_tcp_mtu_probing, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "tcp_base_mss", .data = &sysctl_tcp_base_mss, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .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 }, #ifdef CONFIG_NET_DMA { .procname = "tcp_dma_copybreak", .data = &sysctl_tcp_dma_copybreak, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, #endif { .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_max_ssthresh", .data = &sysctl_tcp_max_ssthresh, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .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 = &zero, .extra2 = &gso_max_segs, }, { .procname = "udp_mem", .data = &sysctl_udp_mem, .maxlen = sizeof(sysctl_udp_mem), .mode = 0644, .proc_handler = proc_doulongvec_minmax, }, { .procname = "udp_rmem_min", .data = &sysctl_udp_rmem_min, .maxlen = sizeof(sysctl_udp_rmem_min), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &one }, { .procname = "udp_wmem_min", .data = &sysctl_udp_wmem_min, .maxlen = sizeof(sysctl_udp_wmem_min), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &one }, { } }; static struct ctl_table ipv4_net_table[] = { { .procname = "icmp_echo_ignore_all", .data = &init_net.ipv4.sysctl_icmp_echo_ignore_all, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "icmp_echo_ignore_broadcasts", .data = &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "icmp_ignore_bogus_error_responses", .data = &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "icmp_errors_use_inbound_ifaddr", .data = &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "icmp_ratelimit", .data = &init_net.ipv4.sysctl_icmp_ratelimit, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_ms_jiffies, }, { .procname = "icmp_ratemask", .data = &init_net.ipv4.sysctl_icmp_ratemask, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "ping_group_range", .data = &init_net.ipv4.sysctl_ping_group_range, .maxlen = sizeof(gid_t)*2, .mode = 0644, .proc_handler = ipv4_ping_group_range, }, { .procname = "tcp_ecn", .data = &init_net.ipv4.sysctl_tcp_ecn, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "ip_local_port_range", .maxlen = sizeof(init_net.ipv4.sysctl_local_ports.range), .data = &init_net.ipv4.sysctl_local_ports.range, .mode = 0644, .proc_handler = ipv4_local_port_range, }, { } }; static __net_init int ipv4_sysctl_init_net(struct net *net) { struct ctl_table *table; table = ipv4_net_table; if (!net_eq(net, &init_net)) { int i; table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL); if (table == NULL) goto err_alloc; /* Update the variables to point into the current struct net */ for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++) table[i].data += (void *)net - (void *)&init_net; /* Don't export sysctls to unprivileged users */ if (net->user_ns != &init_user_ns) table[0].procname = NULL; } /* * Sane defaults - nobody may create ping sockets. * Boot scripts should set this to distro-specific group. */ net->ipv4.sysctl_ping_group_range[0] = make_kgid(&init_user_ns, 1); net->ipv4.sysctl_ping_group_range[1] = make_kgid(&init_user_ns, 0); /* * Set defaults for local port range */ seqlock_init(&net->ipv4.sysctl_local_ports.lock); net->ipv4.sysctl_local_ports.range[0] = 32768; net->ipv4.sysctl_local_ports.range[1] = 61000; net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table); if (net->ipv4.ipv4_hdr == NULL) goto err_reg; return 0; err_reg: if (!net_eq(net, &init_net)) kfree(table); err_alloc: return -ENOMEM; } static __net_exit void ipv4_sysctl_exit_net(struct net *net) { struct ctl_table *table; table = net->ipv4.ipv4_hdr->ctl_table_arg; unregister_net_sysctl_table(net->ipv4.ipv4_hdr); kfree(table); } static __net_initdata struct pernet_operations ipv4_sysctl_ops = { .init = ipv4_sysctl_init_net, .exit = ipv4_sysctl_exit_net, }; static __init int sysctl_ipv4_init(void) { struct ctl_table_header *hdr; struct ctl_table *i; for (i = ipv4_table; i->procname; i++) { if (strcmp(i->procname, "ip_local_reserved_ports") == 0) { i->data = sysctl_local_reserved_ports; break; } } if (!i->procname) return -EINVAL; hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table); if (hdr == NULL) return -ENOMEM; if (register_pernet_subsys(&ipv4_sysctl_ops)) { unregister_net_sysctl_table(hdr); return -ENOMEM; } return 0; } __initcall(sysctl_ipv4_init);