1 #include <linux/mutex.h> 2 #include <linux/socket.h> 3 #include <linux/skbuff.h> 4 #include <net/netlink.h> 5 #include <net/net_namespace.h> 6 #include <linux/module.h> 7 8 #include <linux/inet_diag.h> 9 #include <linux/sock_diag.h> 10 11 static struct sock_diag_handler *sock_diag_handlers[AF_MAX]; 12 static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh); 13 static DEFINE_MUTEX(sock_diag_table_mutex); 14 15 int sock_diag_check_cookie(void *sk, __u32 *cookie) 16 { 17 if ((cookie[0] != INET_DIAG_NOCOOKIE || 18 cookie[1] != INET_DIAG_NOCOOKIE) && 19 ((u32)(unsigned long)sk != cookie[0] || 20 (u32)((((unsigned long)sk) >> 31) >> 1) != cookie[1])) 21 return -ESTALE; 22 else 23 return 0; 24 } 25 EXPORT_SYMBOL_GPL(sock_diag_check_cookie); 26 27 void sock_diag_save_cookie(void *sk, __u32 *cookie) 28 { 29 cookie[0] = (u32)(unsigned long)sk; 30 cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1); 31 } 32 EXPORT_SYMBOL_GPL(sock_diag_save_cookie); 33 34 void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) 35 { 36 mutex_lock(&sock_diag_table_mutex); 37 inet_rcv_compat = fn; 38 mutex_unlock(&sock_diag_table_mutex); 39 } 40 EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat); 41 42 void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) 43 { 44 mutex_lock(&sock_diag_table_mutex); 45 inet_rcv_compat = NULL; 46 mutex_unlock(&sock_diag_table_mutex); 47 } 48 EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat); 49 50 int sock_diag_register(struct sock_diag_handler *hndl) 51 { 52 int err = 0; 53 54 if (hndl->family >= AF_MAX) 55 return -EINVAL; 56 57 mutex_lock(&sock_diag_table_mutex); 58 if (sock_diag_handlers[hndl->family]) 59 err = -EBUSY; 60 else 61 sock_diag_handlers[hndl->family] = hndl; 62 mutex_unlock(&sock_diag_table_mutex); 63 64 return err; 65 } 66 EXPORT_SYMBOL_GPL(sock_diag_register); 67 68 void sock_diag_unregister(struct sock_diag_handler *hnld) 69 { 70 int family = hnld->family; 71 72 if (family >= AF_MAX) 73 return; 74 75 mutex_lock(&sock_diag_table_mutex); 76 BUG_ON(sock_diag_handlers[family] != hnld); 77 sock_diag_handlers[family] = NULL; 78 mutex_unlock(&sock_diag_table_mutex); 79 } 80 EXPORT_SYMBOL_GPL(sock_diag_unregister); 81 82 static inline struct sock_diag_handler *sock_diag_lock_handler(int family) 83 { 84 if (sock_diag_handlers[family] == NULL) 85 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 86 NETLINK_SOCK_DIAG, family); 87 88 mutex_lock(&sock_diag_table_mutex); 89 return sock_diag_handlers[family]; 90 } 91 92 static inline void sock_diag_unlock_handler(struct sock_diag_handler *h) 93 { 94 mutex_unlock(&sock_diag_table_mutex); 95 } 96 97 static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 98 { 99 int err; 100 struct sock_diag_req *req = NLMSG_DATA(nlh); 101 struct sock_diag_handler *hndl; 102 103 if (nlmsg_len(nlh) < sizeof(*req)) 104 return -EINVAL; 105 106 hndl = sock_diag_lock_handler(req->sdiag_family); 107 if (hndl == NULL) 108 err = -ENOENT; 109 else 110 err = hndl->dump(skb, nlh); 111 sock_diag_unlock_handler(hndl); 112 113 return err; 114 } 115 116 static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 117 { 118 int ret; 119 120 switch (nlh->nlmsg_type) { 121 case TCPDIAG_GETSOCK: 122 case DCCPDIAG_GETSOCK: 123 if (inet_rcv_compat == NULL) 124 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 125 NETLINK_SOCK_DIAG, AF_INET); 126 127 mutex_lock(&sock_diag_table_mutex); 128 if (inet_rcv_compat != NULL) 129 ret = inet_rcv_compat(skb, nlh); 130 else 131 ret = -EOPNOTSUPP; 132 mutex_unlock(&sock_diag_table_mutex); 133 134 return ret; 135 case SOCK_DIAG_BY_FAMILY: 136 return __sock_diag_rcv_msg(skb, nlh); 137 default: 138 return -EINVAL; 139 } 140 } 141 142 static DEFINE_MUTEX(sock_diag_mutex); 143 144 static void sock_diag_rcv(struct sk_buff *skb) 145 { 146 mutex_lock(&sock_diag_mutex); 147 netlink_rcv_skb(skb, &sock_diag_rcv_msg); 148 mutex_unlock(&sock_diag_mutex); 149 } 150 151 struct sock *sock_diag_nlsk; 152 EXPORT_SYMBOL_GPL(sock_diag_nlsk); 153 154 static int __init sock_diag_init(void) 155 { 156 sock_diag_nlsk = netlink_kernel_create(&init_net, NETLINK_SOCK_DIAG, 0, 157 sock_diag_rcv, NULL, THIS_MODULE); 158 return sock_diag_nlsk == NULL ? -ENOMEM : 0; 159 } 160 161 static void __exit sock_diag_exit(void) 162 { 163 netlink_kernel_release(sock_diag_nlsk); 164 } 165 166 module_init(sock_diag_init); 167 module_exit(sock_diag_exit); 168 MODULE_LICENSE("GPL"); 169 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG); 170