1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright Gavin Shan, IBM Corporation 2016.
4 */
5
6#include <linux/module.h>
7#include <linux/kernel.h>
8#include <linux/init.h>
9#include <linux/etherdevice.h>
10#include <linux/netdevice.h>
11#include <linux/skbuff.h>
12
13#include <net/ncsi.h>
14#include <net/net_namespace.h>
15#include <net/sock.h>
16#include <net/genetlink.h>
17
18#include "internal.h"
19#include "ncsi-pkt.h"
20
21static const int padding_bytes = 26;
22
23u32 ncsi_calculate_checksum(unsigned char *data, int len)
24{
25	u32 checksum = 0;
26	int i;
27
28	for (i = 0; i < len; i += 2)
29		checksum += (((u32)data[i] << 8) | data[i + 1]);
30
31	checksum = (~checksum + 1);
32	return checksum;
33}
34
35/* This function should be called after the data area has been
36 * populated completely.
37 */
38static void ncsi_cmd_build_header(struct ncsi_pkt_hdr *h,
39				  struct ncsi_cmd_arg *nca)
40{
41	u32 checksum;
42	__be32 *pchecksum;
43
44	h->mc_id        = 0;
45	h->revision     = NCSI_PKT_REVISION;
46	h->reserved     = 0;
47	h->id           = nca->id;
48	h->type         = nca->type;
49	h->channel      = NCSI_TO_CHANNEL(nca->package,
50					  nca->channel);
51	h->length       = htons(nca->payload);
52	h->reserved1[0] = 0;
53	h->reserved1[1] = 0;
54
55	/* Fill with calculated checksum */
56	checksum = ncsi_calculate_checksum((unsigned char *)h,
57					   sizeof(*h) + nca->payload);
58	pchecksum = (__be32 *)((void *)h + sizeof(struct ncsi_pkt_hdr) +
59		    ALIGN(nca->payload, 4));
60	*pchecksum = htonl(checksum);
61}
62
63static int ncsi_cmd_handler_default(struct sk_buff *skb,
64				    struct ncsi_cmd_arg *nca)
65{
66	struct ncsi_cmd_pkt *cmd;
67
68	cmd = skb_put_zero(skb, sizeof(*cmd));
69	ncsi_cmd_build_header(&cmd->cmd.common, nca);
70
71	return 0;
72}
73
74static int ncsi_cmd_handler_sp(struct sk_buff *skb,
75			       struct ncsi_cmd_arg *nca)
76{
77	struct ncsi_cmd_sp_pkt *cmd;
78
79	cmd = skb_put_zero(skb, sizeof(*cmd));
80	cmd->hw_arbitration = nca->bytes[0];
81	ncsi_cmd_build_header(&cmd->cmd.common, nca);
82
83	return 0;
84}
85
86static int ncsi_cmd_handler_dc(struct sk_buff *skb,
87			       struct ncsi_cmd_arg *nca)
88{
89	struct ncsi_cmd_dc_pkt *cmd;
90
91	cmd = skb_put_zero(skb, sizeof(*cmd));
92	cmd->ald = nca->bytes[0];
93	ncsi_cmd_build_header(&cmd->cmd.common, nca);
94
95	return 0;
96}
97
98static int ncsi_cmd_handler_rc(struct sk_buff *skb,
99			       struct ncsi_cmd_arg *nca)
100{
101	struct ncsi_cmd_rc_pkt *cmd;
102
103	cmd = skb_put_zero(skb, sizeof(*cmd));
104	ncsi_cmd_build_header(&cmd->cmd.common, nca);
105
106	return 0;
107}
108
109static int ncsi_cmd_handler_ae(struct sk_buff *skb,
110			       struct ncsi_cmd_arg *nca)
111{
112	struct ncsi_cmd_ae_pkt *cmd;
113
114	cmd = skb_put_zero(skb, sizeof(*cmd));
115	cmd->mc_id = nca->bytes[0];
116	cmd->mode = htonl(nca->dwords[1]);
117	ncsi_cmd_build_header(&cmd->cmd.common, nca);
118
119	return 0;
120}
121
122static int ncsi_cmd_handler_sl(struct sk_buff *skb,
123			       struct ncsi_cmd_arg *nca)
124{
125	struct ncsi_cmd_sl_pkt *cmd;
126
127	cmd = skb_put_zero(skb, sizeof(*cmd));
128	cmd->mode = htonl(nca->dwords[0]);
129	cmd->oem_mode = htonl(nca->dwords[1]);
130	ncsi_cmd_build_header(&cmd->cmd.common, nca);
131
132	return 0;
133}
134
135static int ncsi_cmd_handler_svf(struct sk_buff *skb,
136				struct ncsi_cmd_arg *nca)
137{
138	struct ncsi_cmd_svf_pkt *cmd;
139
140	cmd = skb_put_zero(skb, sizeof(*cmd));
141	cmd->vlan = htons(nca->words[1]);
142	cmd->index = nca->bytes[6];
143	cmd->enable = nca->bytes[7];
144	ncsi_cmd_build_header(&cmd->cmd.common, nca);
145
146	return 0;
147}
148
149static int ncsi_cmd_handler_ev(struct sk_buff *skb,
150			       struct ncsi_cmd_arg *nca)
151{
152	struct ncsi_cmd_ev_pkt *cmd;
153
154	cmd = skb_put_zero(skb, sizeof(*cmd));
155	cmd->mode = nca->bytes[3];
156	ncsi_cmd_build_header(&cmd->cmd.common, nca);
157
158	return 0;
159}
160
161static int ncsi_cmd_handler_sma(struct sk_buff *skb,
162				struct ncsi_cmd_arg *nca)
163{
164	struct ncsi_cmd_sma_pkt *cmd;
165	int i;
166
167	cmd = skb_put_zero(skb, sizeof(*cmd));
168	for (i = 0; i < 6; i++)
169		cmd->mac[i] = nca->bytes[i];
170	cmd->index = nca->bytes[6];
171	cmd->at_e = nca->bytes[7];
172	ncsi_cmd_build_header(&cmd->cmd.common, nca);
173
174	return 0;
175}
176
177static int ncsi_cmd_handler_ebf(struct sk_buff *skb,
178				struct ncsi_cmd_arg *nca)
179{
180	struct ncsi_cmd_ebf_pkt *cmd;
181
182	cmd = skb_put_zero(skb, sizeof(*cmd));
183	cmd->mode = htonl(nca->dwords[0]);
184	ncsi_cmd_build_header(&cmd->cmd.common, nca);
185
186	return 0;
187}
188
189static int ncsi_cmd_handler_egmf(struct sk_buff *skb,
190				 struct ncsi_cmd_arg *nca)
191{
192	struct ncsi_cmd_egmf_pkt *cmd;
193
194	cmd = skb_put_zero(skb, sizeof(*cmd));
195	cmd->mode = htonl(nca->dwords[0]);
196	ncsi_cmd_build_header(&cmd->cmd.common, nca);
197
198	return 0;
199}
200
201static int ncsi_cmd_handler_snfc(struct sk_buff *skb,
202				 struct ncsi_cmd_arg *nca)
203{
204	struct ncsi_cmd_snfc_pkt *cmd;
205
206	cmd = skb_put_zero(skb, sizeof(*cmd));
207	cmd->mode = nca->bytes[0];
208	ncsi_cmd_build_header(&cmd->cmd.common, nca);
209
210	return 0;
211}
212
213static int ncsi_cmd_handler_oem(struct sk_buff *skb,
214				struct ncsi_cmd_arg *nca)
215{
216	struct ncsi_cmd_oem_pkt *cmd;
217	unsigned int len;
218	int payload;
219	/* NC-SI spec DSP_0222_1.2.0, section 8.2.2.2
220	 * requires payload to be padded with 0 to
221	 * 32-bit boundary before the checksum field.
222	 * Ensure the padding bytes are accounted for in
223	 * skb allocation
224	 */
225
226	payload = ALIGN(nca->payload, 4);
227	len = sizeof(struct ncsi_cmd_pkt_hdr) + 4;
228	len += max(payload, padding_bytes);
229
230	cmd = skb_put_zero(skb, len);
231	unsafe_memcpy(&cmd->mfr_id, nca->data, nca->payload,
232		      /* skb allocated with enough to load the payload */);
233	ncsi_cmd_build_header(&cmd->cmd.common, nca);
234
235	return 0;
236}
237
238static struct ncsi_cmd_handler {
239	unsigned char type;
240	int           payload;
241	int           (*handler)(struct sk_buff *skb,
242				 struct ncsi_cmd_arg *nca);
243} ncsi_cmd_handlers[] = {
244	{ NCSI_PKT_CMD_CIS,    0, ncsi_cmd_handler_default },
245	{ NCSI_PKT_CMD_SP,     4, ncsi_cmd_handler_sp      },
246	{ NCSI_PKT_CMD_DP,     0, ncsi_cmd_handler_default },
247	{ NCSI_PKT_CMD_EC,     0, ncsi_cmd_handler_default },
248	{ NCSI_PKT_CMD_DC,     4, ncsi_cmd_handler_dc      },
249	{ NCSI_PKT_CMD_RC,     4, ncsi_cmd_handler_rc      },
250	{ NCSI_PKT_CMD_ECNT,   0, ncsi_cmd_handler_default },
251	{ NCSI_PKT_CMD_DCNT,   0, ncsi_cmd_handler_default },
252	{ NCSI_PKT_CMD_AE,     8, ncsi_cmd_handler_ae      },
253	{ NCSI_PKT_CMD_SL,     8, ncsi_cmd_handler_sl      },
254	{ NCSI_PKT_CMD_GLS,    0, ncsi_cmd_handler_default },
255	{ NCSI_PKT_CMD_SVF,    8, ncsi_cmd_handler_svf     },
256	{ NCSI_PKT_CMD_EV,     4, ncsi_cmd_handler_ev      },
257	{ NCSI_PKT_CMD_DV,     0, ncsi_cmd_handler_default },
258	{ NCSI_PKT_CMD_SMA,    8, ncsi_cmd_handler_sma     },
259	{ NCSI_PKT_CMD_EBF,    4, ncsi_cmd_handler_ebf     },
260	{ NCSI_PKT_CMD_DBF,    0, ncsi_cmd_handler_default },
261	{ NCSI_PKT_CMD_EGMF,   4, ncsi_cmd_handler_egmf    },
262	{ NCSI_PKT_CMD_DGMF,   0, ncsi_cmd_handler_default },
263	{ NCSI_PKT_CMD_SNFC,   4, ncsi_cmd_handler_snfc    },
264	{ NCSI_PKT_CMD_GVI,    0, ncsi_cmd_handler_default },
265	{ NCSI_PKT_CMD_GC,     0, ncsi_cmd_handler_default },
266	{ NCSI_PKT_CMD_GP,     0, ncsi_cmd_handler_default },
267	{ NCSI_PKT_CMD_GCPS,   0, ncsi_cmd_handler_default },
268	{ NCSI_PKT_CMD_GNS,    0, ncsi_cmd_handler_default },
269	{ NCSI_PKT_CMD_GNPTS,  0, ncsi_cmd_handler_default },
270	{ NCSI_PKT_CMD_GPS,    0, ncsi_cmd_handler_default },
271	{ NCSI_PKT_CMD_OEM,   -1, ncsi_cmd_handler_oem     },
272	{ NCSI_PKT_CMD_PLDM,   0, NULL                     },
273	{ NCSI_PKT_CMD_GPUUID, 0, ncsi_cmd_handler_default },
274	{ NCSI_PKT_CMD_GMCMA,  0, ncsi_cmd_handler_default }
275};
276
277static struct ncsi_request *ncsi_alloc_command(struct ncsi_cmd_arg *nca)
278{
279	struct ncsi_dev_priv *ndp = nca->ndp;
280	struct ncsi_dev *nd = &ndp->ndev;
281	struct net_device *dev = nd->dev;
282	int hlen = LL_RESERVED_SPACE(dev);
283	int tlen = dev->needed_tailroom;
284	int payload;
285	int len = hlen + tlen;
286	struct sk_buff *skb;
287	struct ncsi_request *nr;
288
289	nr = ncsi_alloc_request(ndp, nca->req_flags);
290	if (!nr)
291		return NULL;
292
293	/* NCSI command packet has 16-bytes header, payload, 4 bytes checksum.
294	 * Payload needs padding so that the checksum field following payload is
295	 * aligned to 32-bit boundary.
296	 * The packet needs padding if its payload is less than 26 bytes to
297	 * meet 64 bytes minimal ethernet frame length.
298	 */
299	len += sizeof(struct ncsi_cmd_pkt_hdr) + 4;
300	payload = ALIGN(nca->payload, 4);
301	len += max(payload, padding_bytes);
302
303	/* Allocate skb */
304	skb = alloc_skb(len, GFP_ATOMIC);
305	if (!skb) {
306		ncsi_free_request(nr);
307		return NULL;
308	}
309
310	nr->cmd = skb;
311	skb_reserve(skb, hlen);
312	skb_reset_network_header(skb);
313
314	skb->dev = dev;
315	skb->protocol = htons(ETH_P_NCSI);
316
317	return nr;
318}
319
320int ncsi_xmit_cmd(struct ncsi_cmd_arg *nca)
321{
322	struct ncsi_cmd_handler *nch = NULL;
323	struct ncsi_request *nr;
324	unsigned char type;
325	struct ethhdr *eh;
326	int i, ret;
327
328	/* Use OEM generic handler for Netlink request */
329	if (nca->req_flags == NCSI_REQ_FLAG_NETLINK_DRIVEN)
330		type = NCSI_PKT_CMD_OEM;
331	else
332		type = nca->type;
333
334	/* Search for the handler */
335	for (i = 0; i < ARRAY_SIZE(ncsi_cmd_handlers); i++) {
336		if (ncsi_cmd_handlers[i].type == type) {
337			if (ncsi_cmd_handlers[i].handler)
338				nch = &ncsi_cmd_handlers[i];
339			else
340				nch = NULL;
341
342			break;
343		}
344	}
345
346	if (!nch) {
347		netdev_err(nca->ndp->ndev.dev,
348			   "Cannot send packet with type 0x%02x\n", nca->type);
349		return -ENOENT;
350	}
351
352	/* Get packet payload length and allocate the request
353	 * It is expected that if length set as negative in
354	 * handler structure means caller is initializing it
355	 * and setting length in nca before calling xmit function
356	 */
357	if (nch->payload >= 0)
358		nca->payload = nch->payload;
359	nr = ncsi_alloc_command(nca);
360	if (!nr)
361		return -ENOMEM;
362
363	/* track netlink information */
364	if (nca->req_flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
365		nr->snd_seq = nca->info->snd_seq;
366		nr->snd_portid = nca->info->snd_portid;
367		nr->nlhdr = *nca->info->nlhdr;
368	}
369
370	/* Prepare the packet */
371	nca->id = nr->id;
372	ret = nch->handler(nr->cmd, nca);
373	if (ret) {
374		ncsi_free_request(nr);
375		return ret;
376	}
377
378	/* Fill the ethernet header */
379	eh = skb_push(nr->cmd, sizeof(*eh));
380	eh->h_proto = htons(ETH_P_NCSI);
381	eth_broadcast_addr(eh->h_dest);
382
383	/* If mac address received from device then use it for
384	 * source address as unicast address else use broadcast
385	 * address as source address
386	 */
387	if (nca->ndp->gma_flag == 1)
388		memcpy(eh->h_source, nca->ndp->ndev.dev->dev_addr, ETH_ALEN);
389	else
390		eth_broadcast_addr(eh->h_source);
391
392	/* Start the timer for the request that might not have
393	 * corresponding response. Given NCSI is an internal
394	 * connection a 1 second delay should be sufficient.
395	 */
396	nr->enabled = true;
397	mod_timer(&nr->timer, jiffies + 1 * HZ);
398
399	/* Send NCSI packet */
400	skb_get(nr->cmd);
401	ret = dev_queue_xmit(nr->cmd);
402	if (ret < 0) {
403		ncsi_free_request(nr);
404		return ret;
405	}
406
407	return 0;
408}
409