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 23 }, 24 }; 25 26 static const struct ctl_table *unix_table_dup(struct net *net) 27 { 28 struct ctl_table *table; 29 30 table = kmemdup(unix_table, sizeof(unix_table), GFP_KERNEL); 31 if (!table) 32 return NULL; 33 34 table[0].data = &net->unx.sysctl_max_dgram_qlen; 35 36 return table; 37 } 38 39 int __net_init unix_sysctl_register(struct net *net) 40 { 41 const struct ctl_table *table; 42 43 if (net_eq(net, &init_net)) { 44 table = unix_table; 45 } else { 46 table = unix_table_dup(net); 47 if (!table) 48 goto err_alloc; 49 } 50 51 net->unx.ctl = register_net_sysctl_sz(net, "net/unix", table, 52 ARRAY_SIZE(unix_table)); 53 if (net->unx.ctl == NULL) 54 goto err_reg; 55 56 return 0; 57 58 err_reg: 59 if (!net_eq(net, &init_net)) 60 kfree(table); 61 err_alloc: 62 return -ENOMEM; 63 } 64 65 void unix_sysctl_unregister(struct net *net) 66 { 67 const struct ctl_table *table; 68 69 table = net->unx.ctl->ctl_table_arg; 70 unregister_net_sysctl_table(net->unx.ctl); 71 if (!net_eq(net, &init_net)) 72 kfree(table); 73 } 74