// SPDX-License-Identifier: GPL-2.0 /* -*- linux-c -*- * sysctl_net_core.c: sysctl interface to net core subsystem. * * Begun April 1, 1996, Mike Shaver. * Added /proc/sys/net/core directory entry (empty =) ). [MS] */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int zero = 0; static int one = 1; static int two __maybe_unused = 2; static int min_sndbuf = SOCK_MIN_SNDBUF; static int min_rcvbuf = SOCK_MIN_RCVBUF; static int max_skb_frags = MAX_SKB_FRAGS; static long long_one __maybe_unused = 1; static long long_max __maybe_unused = LONG_MAX; static int net_msg_warn; /* Unused, but still a sysctl */ int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0; EXPORT_SYMBOL(sysctl_fb_tunnels_only_for_init_net); #ifdef CONFIG_RPS static int rps_sock_flow_sysctl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { unsigned int orig_size, size; int ret, i; struct ctl_table tmp = { .data = &size, .maxlen = sizeof(size), .mode = table->mode }; struct rps_sock_flow_table *orig_sock_table, *sock_table; static DEFINE_MUTEX(sock_flow_mutex); mutex_lock(&sock_flow_mutex); orig_sock_table = rcu_dereference_protected(rps_sock_flow_table, lockdep_is_held(&sock_flow_mutex)); size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0; ret = proc_dointvec(&tmp, write, buffer, lenp, ppos); if (write) { if (size) { if (size > 1<<29) { /* Enforce limit to prevent overflow */ mutex_unlock(&sock_flow_mutex); return -EINVAL; } size = roundup_pow_of_two(size); if (size != orig_size) { sock_table = vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size)); if (!sock_table) { mutex_unlock(&sock_flow_mutex); return -ENOMEM; } rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1; sock_table->mask = size - 1; } else sock_table = orig_sock_table; for (i = 0; i < size; i++) sock_table->ents[i] = RPS_NO_CPU; } else sock_table = NULL; if (sock_table != orig_sock_table) { rcu_assign_pointer(rps_sock_flow_table, sock_table); if (sock_table) { static_key_slow_inc(&rps_needed); static_key_slow_inc(&rfs_needed); } if (orig_sock_table) { static_key_slow_dec(&rps_needed); static_key_slow_dec(&rfs_needed); synchronize_rcu(); vfree(orig_sock_table); } } } mutex_unlock(&sock_flow_mutex); return ret; } #endif /* CONFIG_RPS */ #ifdef CONFIG_NET_FLOW_LIMIT static DEFINE_MUTEX(flow_limit_update_mutex); static int flow_limit_cpu_sysctl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct sd_flow_limit *cur; struct softnet_data *sd; cpumask_var_t mask; int i, len, ret = 0; if (!alloc_cpumask_var(&mask, GFP_KERNEL)) return -ENOMEM; if (write) { ret = cpumask_parse_user(buffer, *lenp, mask); if (ret) goto done; mutex_lock(&flow_limit_update_mutex); len = sizeof(*cur) + netdev_flow_limit_table_len; for_each_possible_cpu(i) { sd = &per_cpu(softnet_data, i); cur = rcu_dereference_protected(sd->flow_limit, lockdep_is_held(&flow_limit_update_mutex)); if (cur && !cpumask_test_cpu(i, mask)) { RCU_INIT_POINTER(sd->flow_limit, NULL); synchronize_rcu(); kfree(cur); } else if (!cur && cpumask_test_cpu(i, mask)) { cur = kzalloc_node(len, GFP_KERNEL, cpu_to_node(i)); if (!cur) { /* not unwinding previous changes */ ret = -ENOMEM; goto write_unlock; } cur->num_buckets = netdev_flow_limit_table_len; rcu_assign_pointer(sd->flow_limit, cur); } } write_unlock: mutex_unlock(&flow_limit_update_mutex); } else { char kbuf[128]; if (*ppos || !*lenp) { *lenp = 0; goto done; } cpumask_clear(mask); rcu_read_lock(); for_each_possible_cpu(i) { sd = &per_cpu(softnet_data, i); if (rcu_dereference(sd->flow_limit)) cpumask_set_cpu(i, mask); } rcu_read_unlock(); len = min(sizeof(kbuf) - 1, *lenp); len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask)); if (!len) { *lenp = 0; goto done; } if (len < *lenp) kbuf[len++] = '\n'; if (copy_to_user(buffer, kbuf, len)) { ret = -EFAULT; goto done; } *lenp = len; *ppos += len; } done: free_cpumask_var(mask); return ret; } static int flow_limit_table_len_sysctl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { unsigned int old, *ptr; int ret; mutex_lock(&flow_limit_update_mutex); ptr = table->data; old = *ptr; ret = proc_dointvec(table, write, buffer, lenp, ppos); if (!ret && write && !is_power_of_2(*ptr)) { *ptr = old; ret = -EINVAL; } mutex_unlock(&flow_limit_update_mutex); return ret; } #endif /* CONFIG_NET_FLOW_LIMIT */ #ifdef CONFIG_NET_SCHED static int set_default_qdisc(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { char id[IFNAMSIZ]; struct ctl_table tbl = { .data = id, .maxlen = IFNAMSIZ, }; int ret; qdisc_get_default(id, IFNAMSIZ); ret = proc_dostring(&tbl, write, buffer, lenp, ppos); if (write && ret == 0) ret = qdisc_set_default(id); return ret; } #endif static int proc_do_dev_weight(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { int ret; ret = proc_dointvec(table, write, buffer, lenp, ppos); if (ret != 0) return ret; dev_rx_weight = weight_p * dev_weight_rx_bias; dev_tx_weight = weight_p * dev_weight_tx_bias; return ret; } static int proc_do_rss_key(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table fake_table; char buf[NETDEV_RSS_KEY_LEN * 3]; snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key); fake_table.data = buf; fake_table.maxlen = sizeof(buf); return proc_dostring(&fake_table, write, buffer, lenp, ppos); } #ifdef CONFIG_BPF_JIT static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { int ret, jit_enable = *(int *)table->data; struct ctl_table tmp = *table; if (write && !capable(CAP_SYS_ADMIN)) return -EPERM; tmp.data = &jit_enable; ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); if (write && !ret) { if (jit_enable < 2 || (jit_enable == 2 && bpf_dump_raw_ok(current_cred()))) { *(int *)table->data = jit_enable; if (jit_enable == 2) pr_warn("bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging!\n"); } else { ret = -EPERM; } } return ret; } # ifdef CONFIG_HAVE_EBPF_JIT static int proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { if (!capable(CAP_SYS_ADMIN)) return -EPERM; return proc_dointvec_minmax(table, write, buffer, lenp, ppos); } # endif /* CONFIG_HAVE_EBPF_JIT */ static int proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { if (!capable(CAP_SYS_ADMIN)) return -EPERM; return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); } #endif static struct ctl_table net_core_table[] = { #ifdef CONFIG_NET { .procname = "wmem_max", .data = &sysctl_wmem_max, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &min_sndbuf, }, { .procname = "rmem_max", .data = &sysctl_rmem_max, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &min_rcvbuf, }, { .procname = "wmem_default", .data = &sysctl_wmem_default, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &min_sndbuf, }, { .procname = "rmem_default", .data = &sysctl_rmem_default, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &min_rcvbuf, }, { .procname = "dev_weight", .data = &weight_p, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_do_dev_weight, }, { .procname = "dev_weight_rx_bias", .data = &dev_weight_rx_bias, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_do_dev_weight, }, { .procname = "dev_weight_tx_bias", .data = &dev_weight_tx_bias, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_do_dev_weight, }, { .procname = "netdev_max_backlog", .data = &netdev_max_backlog, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "netdev_rss_key", .data = &netdev_rss_key, .maxlen = sizeof(int), .mode = 0444, .proc_handler = proc_do_rss_key, }, #ifdef CONFIG_BPF_JIT { .procname = "bpf_jit_enable", .data = &bpf_jit_enable, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax_bpf_enable, # ifdef CONFIG_BPF_JIT_ALWAYS_ON .extra1 = &one, .extra2 = &one, # else .extra1 = &zero, .extra2 = &two, # endif }, # ifdef CONFIG_HAVE_EBPF_JIT { .procname = "bpf_jit_harden", .data = &bpf_jit_harden, .maxlen = sizeof(int), .mode = 0600, .proc_handler = proc_dointvec_minmax_bpf_restricted, .extra1 = &zero, .extra2 = &two, }, { .procname = "bpf_jit_kallsyms", .data = &bpf_jit_kallsyms, .maxlen = sizeof(int), .mode = 0600, .proc_handler = proc_dointvec_minmax_bpf_restricted, .extra1 = &zero, .extra2 = &one, }, # endif { .procname = "bpf_jit_limit", .data = &bpf_jit_limit, .maxlen = sizeof(long), .mode = 0600, .proc_handler = proc_dolongvec_minmax_bpf_restricted, .extra1 = &long_one, .extra2 = &long_max, }, #endif { .procname = "netdev_tstamp_prequeue", .data = &netdev_tstamp_prequeue, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "message_cost", .data = &net_ratelimit_state.interval, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .procname = "message_burst", .data = &net_ratelimit_state.burst, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "optmem_max", .data = &sysctl_optmem_max, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "tstamp_allow_data", .data = &sysctl_tstamp_allow_data, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one }, #ifdef CONFIG_RPS { .procname = "rps_sock_flow_entries", .maxlen = sizeof(int), .mode = 0644, .proc_handler = rps_sock_flow_sysctl }, #endif #ifdef CONFIG_NET_FLOW_LIMIT { .procname = "flow_limit_cpu_bitmap", .mode = 0644, .proc_handler = flow_limit_cpu_sysctl }, { .procname = "flow_limit_table_len", .data = &netdev_flow_limit_table_len, .maxlen = sizeof(int), .mode = 0644, .proc_handler = flow_limit_table_len_sysctl }, #endif /* CONFIG_NET_FLOW_LIMIT */ #ifdef CONFIG_NET_RX_BUSY_POLL { .procname = "busy_poll", .data = &sysctl_net_busy_poll, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, }, { .procname = "busy_read", .data = &sysctl_net_busy_read, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, }, #endif #ifdef CONFIG_NET_SCHED { .procname = "default_qdisc", .mode = 0644, .maxlen = IFNAMSIZ, .proc_handler = set_default_qdisc }, #endif #endif /* CONFIG_NET */ { .procname = "netdev_budget", .data = &netdev_budget, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "warnings", .data = &net_msg_warn, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, { .procname = "max_skb_frags", .data = &sysctl_max_skb_frags, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &one, .extra2 = &max_skb_frags, }, { .procname = "netdev_budget_usecs", .data = &netdev_budget_usecs, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, }, { .procname = "fb_tunnels_only_for_init_net", .data = &sysctl_fb_tunnels_only_for_init_net, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, { } }; static struct ctl_table netns_core_table[] = { { .procname = "somaxconn", .data = &init_net.core.sysctl_somaxconn, .maxlen = sizeof(int), .mode = 0644, .extra1 = &zero, .proc_handler = proc_dointvec_minmax }, { } }; static __net_init int sysctl_core_net_init(struct net *net) { struct ctl_table *tbl; tbl = netns_core_table; if (!net_eq(net, &init_net)) { tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL); if (tbl == NULL) goto err_dup; tbl[0].data = &net->core.sysctl_somaxconn; /* Don't export any sysctls to unprivileged users */ if (net->user_ns != &init_user_ns) { tbl[0].procname = NULL; } } net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl); if (net->core.sysctl_hdr == NULL) goto err_reg; return 0; err_reg: if (tbl != netns_core_table) kfree(tbl); err_dup: return -ENOMEM; } static __net_exit void sysctl_core_net_exit(struct net *net) { struct ctl_table *tbl; tbl = net->core.sysctl_hdr->ctl_table_arg; unregister_net_sysctl_table(net->core.sysctl_hdr); BUG_ON(tbl == netns_core_table); kfree(tbl); } static __net_initdata struct pernet_operations sysctl_core_ops = { .init = sysctl_core_net_init, .exit = sysctl_core_net_exit, }; static __init int sysctl_core_init(void) { register_net_sysctl(&init_net, "net/core", net_core_table); return register_pernet_subsys(&sysctl_core_ops); } fs_initcall(sysctl_core_init);