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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 | /* * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved. * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/export.h> #include <linux/etherdevice.h> #include <linux/netlink.h> #include <asm/byteorder.h> #include <net/sock.h> #include "netlink_k.h" #if defined(DEFINE_MUTEX) static DEFINE_MUTEX(netlink_mutex); #else static struct semaphore netlink_mutex; #define mutex_lock(x) down(x) #define mutex_unlock(x) up(x) #endif #define ND_MAX_GROUP 30 #define ND_IFINDEX_LEN sizeof(int) #define ND_NLMSG_SPACE(len) (NLMSG_SPACE(len) + ND_IFINDEX_LEN) #define ND_NLMSG_DATA(nlh) ((void *)((char *)NLMSG_DATA(nlh) + \ ND_IFINDEX_LEN)) #define ND_NLMSG_S_LEN(len) (len+ND_IFINDEX_LEN) #define ND_NLMSG_R_LEN(nlh) (nlh->nlmsg_len-ND_IFINDEX_LEN) #define ND_NLMSG_IFIDX(nlh) NLMSG_DATA(nlh) #define ND_MAX_MSG_LEN (1024 * 32) static void (*rcv_cb)(struct net_device *dev, u16 type, void *msg, int len); static void netlink_rcv_cb(struct sk_buff *skb) { struct nlmsghdr *nlh; struct net_device *dev; u32 mlen; void *msg; int ifindex; if (!rcv_cb) { pr_err("nl cb - unregistered\n"); return; } if (skb->len < NLMSG_SPACE(0)) { pr_err("nl cb - invalid skb length\n"); return; } nlh = (struct nlmsghdr *)skb->data; if (skb->len < nlh->nlmsg_len || nlh->nlmsg_len > ND_MAX_MSG_LEN) { pr_err("nl cb - invalid length (%d,%d)\n", skb->len, nlh->nlmsg_len); return; } memcpy(&ifindex, ND_NLMSG_IFIDX(nlh), ND_IFINDEX_LEN); msg = ND_NLMSG_DATA(nlh); mlen = ND_NLMSG_R_LEN(nlh); dev = dev_get_by_index(&init_net, ifindex); if (dev) { rcv_cb(dev, nlh->nlmsg_type, msg, mlen); dev_put(dev); } else { pr_err("nl cb - dev (%d) not found\n", ifindex); } } static void netlink_rcv(struct sk_buff *skb) { mutex_lock(&netlink_mutex); netlink_rcv_cb(skb); mutex_unlock(&netlink_mutex); } struct sock *netlink_init(int unit, void (*cb)(struct net_device *dev, u16 type, void *msg, int len)) { struct sock *sock; struct netlink_kernel_cfg cfg = { .input = netlink_rcv, }; #if !defined(DEFINE_MUTEX) init_MUTEX(&netlink_mutex); #endif sock = netlink_kernel_create(&init_net, unit, &cfg); if (sock) rcv_cb = cb; return sock; } void netlink_exit(struct sock *sock) { sock_release(sock->sk_socket); } int netlink_send(struct sock *sock, int group, u16 type, void *msg, int len) { static u32 seq; struct sk_buff *skb = NULL; struct nlmsghdr *nlh; int ret = 0; if (group > ND_MAX_GROUP) return -EINVAL; if (!netlink_has_listeners(sock, group+1)) return -ESRCH; skb = alloc_skb(NLMSG_SPACE(len), GFP_ATOMIC); if (!skb) return -ENOMEM; seq++; nlh = nlmsg_put(skb, 0, seq, type, len, 0); memcpy(NLMSG_DATA(nlh), msg, len); NETLINK_CB(skb).portid = 0; NETLINK_CB(skb).dst_group = 0; ret = netlink_broadcast(sock, skb, 0, group+1, GFP_ATOMIC); if (!ret) return len; if (ret != -ESRCH) pr_err("nl broadcast g=%d, t=%d, l=%d, r=%d\n", group, type, len, ret); else if (netlink_has_listeners(sock, group+1)) return -EAGAIN; return ret; } |