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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 | // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/export.h> #include <linux/mutex.h> #include <linux/etherdevice.h> #include <linux/netlink.h> #include <asm/byteorder.h> #include <net/sock.h> #include "netlink_k.h" static DEFINE_MUTEX(netlink_mutex); #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_HDRLEN) { 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, }; sock = netlink_kernel_create(&init_net, unit, &cfg); if (sock) rcv_cb = cb; return sock; } int netlink_send(struct sock *sock, int group, u16 type, void *msg, int len, struct net_device *dev) { 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) netdev_err(dev, "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; } |