1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * NET4: Sysctl interface to net af_unix subsystem. 4 * 5 * Authors: Mike Shaver. 6 */ 7 8 #include <linux/slab.h> 9 #include <linux/string.h> 10 #include <linux/sysctl.h> 11 #include <net/af_unix.h> 12 #include <net/net_namespace.h> 13 14 #include "af_unix.h" 15 16 static const struct ctl_table unix_table[] = { 17 { 18 .procname = "max_dgram_qlen", 19 .data = &init_net.unx.sysctl_max_dgram_qlen, 20 .maxlen = sizeof(int), 21 .mode = 0644, 22 .proc_handler = proc_dointvec_minmax, 23 .extra1 = SYSCTL_ZERO, 24 .extra2 = SYSCTL_INT_MAX, 25 }, 26 }; 27 28 static const struct ctl_table *unix_table_dup(struct net *net) 29 { 30 struct ctl_table *table; 31 32 table = kmemdup(unix_table, sizeof(unix_table), GFP_KERNEL); 33 if (!table) 34 return NULL; 35 36 table[0].data = &net->unx.sysctl_max_dgram_qlen; 37 38 return table; 39 } 40 41 int __net_init unix_sysctl_register(struct net *net) 42 { 43 const struct ctl_table *table; 44 45 if (net_eq(net, &init_net)) { 46 table = unix_table; 47 } else { 48 table = unix_table_dup(net); 49 if (!table) 50 goto err_alloc; 51 } 52 53 net->unx.ctl = register_net_sysctl_sz(net, "net/unix", table, 54 ARRAY_SIZE(unix_table)); 55 if (net->unx.ctl == NULL) 56 goto err_reg; 57 58 return 0; 59 60 err_reg: 61 if (!net_eq(net, &init_net)) 62 kfree(table); 63 err_alloc: 64 return -ENOMEM; 65 } 66 67 void unix_sysctl_unregister(struct net *net) 68 { 69 const struct ctl_table *table; 70 71 table = net->unx.ctl->ctl_table_arg; 72 unregister_net_sysctl_table(net->unx.ctl); 73 if (!net_eq(net, &init_net)) 74 kfree(table); 75 } 76