Shad Ansari | 2f7f9be | 2017-06-07 13:34:53 -0700 | [diff] [blame^] | 1 | /* |
| 2 | <:copyright-BRCM:2016:DUAL/GPL:standard |
| 3 | |
| 4 | Broadcom Proprietary and Confidential.(c) 2016 Broadcom |
| 5 | All Rights Reserved |
| 6 | |
| 7 | Unless you and Broadcom execute a separate written software license |
| 8 | agreement governing use of this software, this software is licensed |
| 9 | to you under the terms of the GNU General Public License version 2 |
| 10 | (the "GPL"), available at http://www.broadcom.com/licenses/GPLv2.php, |
| 11 | with the following added to such license: |
| 12 | |
| 13 | As a special exception, the copyright holders of this software give |
| 14 | you permission to link this software with independent modules, and |
| 15 | to copy and distribute the resulting executable under terms of your |
| 16 | choice, provided that you also meet, for each linked independent |
| 17 | module, the terms and conditions of the license of that module. |
| 18 | An independent module is a module which is not derived from this |
| 19 | software. The special exception does not apply to any modifications |
| 20 | of the software. |
| 21 | |
| 22 | Not withstanding the above, under no circumstances may you combine |
| 23 | this software in any way with any other Broadcom software provided |
| 24 | under a license other than the GPL, without Broadcom's express prior |
| 25 | written consent. |
| 26 | |
| 27 | :> |
| 28 | */ |
| 29 | |
| 30 | /* |
| 31 | * nl_transport.c |
| 32 | * |
| 33 | * NL-socket based transport. Kernel space module |
| 34 | * |
| 35 | */ |
| 36 | #include <linux/module.h> /* Needed by all modules */ |
| 37 | #include <linux/kernel.h> /* Needed for KERN_INFO */ |
| 38 | #include <net/netlink.h> |
| 39 | #include <net/sock.h> |
| 40 | #include <linux/netdevice.h> |
| 41 | #include <linux/version.h> |
| 42 | |
| 43 | #include <bcmolt_tr_mux.h> |
| 44 | #include <bcmolt_tr_nl_driver.h> |
| 45 | #include "bcmolt_tr_nl.h" |
| 46 | |
| 47 | #define BCMTR_MEM_PACKETS 10000 |
| 48 | #define BCMTR_MEM_OVERHEAD SKB_TRUESIZE(1024) |
| 49 | #define BCMTR_MIN_RCVBUF_SIZE (BCMTR_MEM_PACKETS * BCMTR_MEM_OVERHEAD) |
| 50 | |
| 51 | struct sock *bcmtr_nl_sock = NULL; |
| 52 | |
| 53 | /* Netlink operations. This driver overrides a couple */ |
| 54 | static struct proto_ops bcmtr_nl_ops; |
| 55 | static int (*netlink_release_org)(struct socket *sock); |
| 56 | |
| 57 | struct bcmtr_nl |
| 58 | { |
| 59 | bcmtrmux_channel channel[BCMTR_MAX_OLTS]; |
| 60 | int pid; |
| 61 | struct sock *sk; |
| 62 | }; |
| 63 | |
| 64 | static int bcmtr_netlink_release(struct socket *sock) |
| 65 | { |
| 66 | struct sock *sk = sock->sk; |
| 67 | struct bcmtr_nl *nlb = sk->sk_user_data; |
| 68 | if (nlb) |
| 69 | { |
| 70 | int i; |
| 71 | for (i = 0; i < BCMTR_MAX_OLTS; i++) |
| 72 | { |
| 73 | if (nlb->channel[i]) |
| 74 | bcmtrmux_channel_unregister(i, nlb->channel[i]); |
| 75 | } |
| 76 | kfree(nlb); |
| 77 | sk->sk_user_data = NULL; |
| 78 | } |
| 79 | return netlink_release_org(sock); |
| 80 | } |
| 81 | |
| 82 | /** Receive message handler */ |
| 83 | static void _bcmtr_nl_recv(bcmolt_devid device, bcmos_buf *buf, bcmtrmux_channel channel, void *data) |
| 84 | { |
| 85 | uint32_t data_length = bcmos_buf_length(buf); |
| 86 | uint32_t device_u32 = (uint32_t)device; |
| 87 | struct bcmtr_nl *nlb = (struct bcmtr_nl *)data; |
| 88 | uint8_t *p_device; |
| 89 | int r; |
| 90 | |
| 91 | NETLINK_CB(&(buf->skb)).dst_group = 0; /* not in mcast group */ |
| 92 | |
| 93 | /* Now a tricky part. nlmsg_put() assumes that skb is empty and extends it |
| 94 | * by total msg size. We don't want it. Reserve room for nlmsg header and then |
| 95 | * set size to 0 and let nlmsg_put() restore it |
| 96 | */ |
| 97 | if (unlikely(skb_headroom(&buf->skb) < NLMSG_HDRLEN + sizeof(uint32_t))) |
| 98 | { |
| 99 | printk(KERN_INFO "%s: can't prepend NL header\n", __FUNCTION__); |
| 100 | bcmos_free(buf); |
| 101 | return; |
| 102 | } |
| 103 | __skb_push(&buf->skb, NLMSG_HDRLEN + sizeof(uint32_t)); |
| 104 | /* Store device immediately after the NL header */ |
| 105 | p_device = buf->skb.data + NLMSG_HDRLEN; |
| 106 | memcpy(p_device, &device_u32, sizeof(uint32_t)); |
| 107 | __skb_trim(&buf->skb, 0); |
| 108 | nlmsg_put(&buf->skb, 0, 0, NLMSG_DONE, data_length + sizeof(uint32_t), 0); |
| 109 | |
| 110 | r = nlmsg_unicast(nlb->sk, &buf->skb, nlb->pid); |
| 111 | if (r) |
| 112 | { |
| 113 | printk(KERN_INFO "%s: nlmsg_unicast() --> %d len=%u rm_alloc=%d recvbuf=%d\n", |
| 114 | __FUNCTION__, r, data_length, atomic_read(&nlb->sk->sk_rmem_alloc), nlb->sk->sk_rcvbuf); |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | void bcmtr_nl_input(struct sk_buff *skb) |
| 119 | { |
| 120 | struct nlmsghdr *nlh; |
| 121 | struct bcmtr_nl *nlb; |
| 122 | uint32_t device; |
| 123 | bcmos_errno rc; |
| 124 | |
| 125 | nlh = nlmsg_hdr(skb); |
| 126 | |
| 127 | if(NLMSG_OK(nlh, skb->len)) |
| 128 | { |
| 129 | #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0) |
| 130 | struct sock *sk = NETLINK_CB(skb).sk; |
| 131 | #else |
| 132 | struct sock *sk = NETLINK_CB(skb).ssk; |
| 133 | #endif |
| 134 | |
| 135 | /* channel is stored in user_data. If it is 0 - that means that channel |
| 136 | * is not allocated yet. Do it here |
| 137 | */ |
| 138 | if (!sk->sk_user_data) |
| 139 | { |
| 140 | nlb = kmalloc(sizeof(*nlb), GFP_KERNEL); |
| 141 | if (!nlb) |
| 142 | { |
| 143 | printk(KERN_INFO "%s: can't allocate NLB\n", __FUNCTION__); |
| 144 | return; |
| 145 | } |
| 146 | memset(nlb, 0, sizeof(*nlb)); |
| 147 | nlb->pid = nlh->nlmsg_pid; |
| 148 | nlb->sk = sk; |
| 149 | sk->sk_user_data = nlb; |
| 150 | |
| 151 | /* Override release callback in order to cleanup */ |
| 152 | bcmtr_nl_ops = *sk->sk_socket->ops; |
| 153 | netlink_release_org = bcmtr_nl_ops.release; |
| 154 | bcmtr_nl_ops.release = bcmtr_netlink_release; |
| 155 | sk->sk_socket->ops = &bcmtr_nl_ops; |
| 156 | |
| 157 | /* Override sk_rcvbuf size. Set min */ |
| 158 | if (sk->sk_rcvbuf < BCMTR_MIN_RCVBUF_SIZE) |
| 159 | { |
| 160 | sk->sk_rcvbuf = BCMTR_MIN_RCVBUF_SIZE; |
| 161 | } |
| 162 | } |
| 163 | else |
| 164 | { |
| 165 | nlb = (struct bcmtr_nl *)sk->sk_user_data; |
| 166 | } |
| 167 | |
| 168 | /* Device id follows NLMSG header */ |
| 169 | device = skb->data[NLMSG_HDRLEN]; |
| 170 | if (device >= BCMTR_MAX_OLTS) |
| 171 | { |
| 172 | printk(KERN_INFO "%s: device %u is insane\n", __FUNCTION__, device); |
| 173 | return; |
| 174 | } |
| 175 | |
| 176 | if (!nlb->channel[device]) |
| 177 | { |
| 178 | bcmtrmux_channel channel = BCMTRMUX_CHANNEL_AUTO_ASSIGN; |
| 179 | |
| 180 | rc = bcmtrmux_channel_register(device, &channel, _bcmtr_nl_recv, nlb); |
| 181 | if (rc) |
| 182 | { |
| 183 | printk(KERN_INFO "%s: can't register channel for device %u. rc=%d\n", __FUNCTION__, device, (int)rc); |
| 184 | return; |
| 185 | } |
| 186 | nlb->channel[device] = channel; |
| 187 | } |
| 188 | |
| 189 | |
| 190 | /* Cut NL header + device */ |
| 191 | skb_pull(skb, NLMSG_HDRLEN + sizeof(uint32_t)); |
| 192 | |
| 193 | /* Clone skb because caller will release the original one */ |
| 194 | skb = skb_clone(skb, 0); |
| 195 | if (!skb) |
| 196 | { |
| 197 | |
| 198 | printk(KERN_ERR "Failed to allocate new skb\n"); |
| 199 | return; |
| 200 | } |
| 201 | |
| 202 | /* Forward to the mux */ |
| 203 | bcmtrmux_rx_from_host(device, nlb->channel[device], (bcmos_buf *)skb); |
| 204 | } |
| 205 | else |
| 206 | { |
| 207 | printk(KERN_INFO "%s: invalid message received frpm pid %d\n", __FUNCTION__, nlh->nlmsg_pid); |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | static struct netlink_kernel_cfg bcmtr_nl_cfg = { |
| 212 | .input = bcmtr_nl_input, |
| 213 | }; |
| 214 | |
| 215 | bcmos_errno bcmtr_nl_init(void) |
| 216 | { |
| 217 | printk(KERN_INFO "Maple netlink-based raw driver transport driver\n"); |
| 218 | bcmtr_nl_sock = netlink_kernel_create(&init_net, BCMTR_NL_FAMILY, &bcmtr_nl_cfg); |
| 219 | if(!bcmtr_nl_sock) |
| 220 | return BCM_ERR_NOMEM; |
| 221 | return BCM_ERR_OK; |
| 222 | } |
| 223 | |
| 224 | void bcmtr_nl_exit(void) |
| 225 | { |
| 226 | printk("Maple netlink-based raw driver terminated\n"); |
| 227 | if (bcmtr_nl_sock) |
| 228 | { |
| 229 | netlink_kernel_release(bcmtr_nl_sock); |
| 230 | bcmtr_nl_sock = NULL; |
| 231 | } |
| 232 | } |