xref: /linux/net/ncsi/ncsi-cmd.c (revision 71e2f4dd5a65bd8dbca0b77661e75eea471168f8)
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 
21 u32 ncsi_calculate_checksum(unsigned char *data, int len)
22 {
23 	u32 checksum = 0;
24 	int i;
25 
26 	for (i = 0; i < len; i += 2)
27 		checksum += (((u32)data[i] << 8) | data[i + 1]);
28 
29 	checksum = (~checksum + 1);
30 	return checksum;
31 }
32 
33 /* This function should be called after the data area has been
34  * populated completely.
35  */
36 static void ncsi_cmd_build_header(struct ncsi_pkt_hdr *h,
37 				  struct ncsi_cmd_arg *nca)
38 {
39 	u32 checksum;
40 	__be32 *pchecksum;
41 
42 	h->mc_id        = 0;
43 	h->revision     = NCSI_PKT_REVISION;
44 	h->reserved     = 0;
45 	h->id           = nca->id;
46 	h->type         = nca->type;
47 	h->channel      = NCSI_TO_CHANNEL(nca->package,
48 					  nca->channel);
49 	h->length       = htons(nca->payload);
50 	h->reserved1[0] = 0;
51 	h->reserved1[1] = 0;
52 
53 	/* Fill with calculated checksum */
54 	checksum = ncsi_calculate_checksum((unsigned char *)h,
55 					   sizeof(*h) + nca->payload);
56 	pchecksum = (__be32 *)((void *)h + sizeof(struct ncsi_pkt_hdr) +
57 		    ALIGN(nca->payload, 4));
58 	*pchecksum = htonl(checksum);
59 }
60 
61 static int ncsi_cmd_handler_default(struct sk_buff *skb,
62 				    struct ncsi_cmd_arg *nca)
63 {
64 	struct ncsi_cmd_pkt *cmd;
65 
66 	cmd = skb_put_zero(skb, sizeof(*cmd));
67 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
68 
69 	return 0;
70 }
71 
72 static int ncsi_cmd_handler_sp(struct sk_buff *skb,
73 			       struct ncsi_cmd_arg *nca)
74 {
75 	struct ncsi_cmd_sp_pkt *cmd;
76 
77 	cmd = skb_put_zero(skb, sizeof(*cmd));
78 	cmd->hw_arbitration = nca->bytes[0];
79 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
80 
81 	return 0;
82 }
83 
84 static int ncsi_cmd_handler_dc(struct sk_buff *skb,
85 			       struct ncsi_cmd_arg *nca)
86 {
87 	struct ncsi_cmd_dc_pkt *cmd;
88 
89 	cmd = skb_put_zero(skb, sizeof(*cmd));
90 	cmd->ald = nca->bytes[0];
91 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
92 
93 	return 0;
94 }
95 
96 static int ncsi_cmd_handler_rc(struct sk_buff *skb,
97 			       struct ncsi_cmd_arg *nca)
98 {
99 	struct ncsi_cmd_rc_pkt *cmd;
100 
101 	cmd = skb_put_zero(skb, sizeof(*cmd));
102 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
103 
104 	return 0;
105 }
106 
107 static int ncsi_cmd_handler_ae(struct sk_buff *skb,
108 			       struct ncsi_cmd_arg *nca)
109 {
110 	struct ncsi_cmd_ae_pkt *cmd;
111 
112 	cmd = skb_put_zero(skb, sizeof(*cmd));
113 	cmd->mc_id = nca->bytes[0];
114 	cmd->mode = htonl(nca->dwords[1]);
115 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
116 
117 	return 0;
118 }
119 
120 static int ncsi_cmd_handler_sl(struct sk_buff *skb,
121 			       struct ncsi_cmd_arg *nca)
122 {
123 	struct ncsi_cmd_sl_pkt *cmd;
124 
125 	cmd = skb_put_zero(skb, sizeof(*cmd));
126 	cmd->mode = htonl(nca->dwords[0]);
127 	cmd->oem_mode = htonl(nca->dwords[1]);
128 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
129 
130 	return 0;
131 }
132 
133 static int ncsi_cmd_handler_svf(struct sk_buff *skb,
134 				struct ncsi_cmd_arg *nca)
135 {
136 	struct ncsi_cmd_svf_pkt *cmd;
137 
138 	cmd = skb_put_zero(skb, sizeof(*cmd));
139 	cmd->vlan = htons(nca->words[1]);
140 	cmd->index = nca->bytes[6];
141 	cmd->enable = nca->bytes[7];
142 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
143 
144 	return 0;
145 }
146 
147 static int ncsi_cmd_handler_ev(struct sk_buff *skb,
148 			       struct ncsi_cmd_arg *nca)
149 {
150 	struct ncsi_cmd_ev_pkt *cmd;
151 
152 	cmd = skb_put_zero(skb, sizeof(*cmd));
153 	cmd->mode = nca->bytes[3];
154 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
155 
156 	return 0;
157 }
158 
159 static int ncsi_cmd_handler_sma(struct sk_buff *skb,
160 				struct ncsi_cmd_arg *nca)
161 {
162 	struct ncsi_cmd_sma_pkt *cmd;
163 	int i;
164 
165 	cmd = skb_put_zero(skb, sizeof(*cmd));
166 	for (i = 0; i < 6; i++)
167 		cmd->mac[i] = nca->bytes[i];
168 	cmd->index = nca->bytes[6];
169 	cmd->at_e = nca->bytes[7];
170 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
171 
172 	return 0;
173 }
174 
175 static int ncsi_cmd_handler_ebf(struct sk_buff *skb,
176 				struct ncsi_cmd_arg *nca)
177 {
178 	struct ncsi_cmd_ebf_pkt *cmd;
179 
180 	cmd = skb_put_zero(skb, sizeof(*cmd));
181 	cmd->mode = htonl(nca->dwords[0]);
182 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
183 
184 	return 0;
185 }
186 
187 static int ncsi_cmd_handler_egmf(struct sk_buff *skb,
188 				 struct ncsi_cmd_arg *nca)
189 {
190 	struct ncsi_cmd_egmf_pkt *cmd;
191 
192 	cmd = skb_put_zero(skb, sizeof(*cmd));
193 	cmd->mode = htonl(nca->dwords[0]);
194 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
195 
196 	return 0;
197 }
198 
199 static int ncsi_cmd_handler_snfc(struct sk_buff *skb,
200 				 struct ncsi_cmd_arg *nca)
201 {
202 	struct ncsi_cmd_snfc_pkt *cmd;
203 
204 	cmd = skb_put_zero(skb, sizeof(*cmd));
205 	cmd->mode = nca->bytes[0];
206 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
207 
208 	return 0;
209 }
210 
211 static int ncsi_cmd_handler_oem(struct sk_buff *skb,
212 				struct ncsi_cmd_arg *nca)
213 {
214 	struct ncsi_cmd_oem_pkt *cmd;
215 	unsigned int len;
216 
217 	len = sizeof(struct ncsi_cmd_pkt_hdr) + 4;
218 	if (nca->payload < 26)
219 		len += 26;
220 	else
221 		len += nca->payload;
222 
223 	cmd = skb_put_zero(skb, len);
224 	memcpy(&cmd->mfr_id, nca->data, nca->payload);
225 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
226 
227 	return 0;
228 }
229 
230 static struct ncsi_cmd_handler {
231 	unsigned char type;
232 	int           payload;
233 	int           (*handler)(struct sk_buff *skb,
234 				 struct ncsi_cmd_arg *nca);
235 } ncsi_cmd_handlers[] = {
236 	{ NCSI_PKT_CMD_CIS,    0, ncsi_cmd_handler_default },
237 	{ NCSI_PKT_CMD_SP,     4, ncsi_cmd_handler_sp      },
238 	{ NCSI_PKT_CMD_DP,     0, ncsi_cmd_handler_default },
239 	{ NCSI_PKT_CMD_EC,     0, ncsi_cmd_handler_default },
240 	{ NCSI_PKT_CMD_DC,     4, ncsi_cmd_handler_dc      },
241 	{ NCSI_PKT_CMD_RC,     4, ncsi_cmd_handler_rc      },
242 	{ NCSI_PKT_CMD_ECNT,   0, ncsi_cmd_handler_default },
243 	{ NCSI_PKT_CMD_DCNT,   0, ncsi_cmd_handler_default },
244 	{ NCSI_PKT_CMD_AE,     8, ncsi_cmd_handler_ae      },
245 	{ NCSI_PKT_CMD_SL,     8, ncsi_cmd_handler_sl      },
246 	{ NCSI_PKT_CMD_GLS,    0, ncsi_cmd_handler_default },
247 	{ NCSI_PKT_CMD_SVF,    8, ncsi_cmd_handler_svf     },
248 	{ NCSI_PKT_CMD_EV,     4, ncsi_cmd_handler_ev      },
249 	{ NCSI_PKT_CMD_DV,     0, ncsi_cmd_handler_default },
250 	{ NCSI_PKT_CMD_SMA,    8, ncsi_cmd_handler_sma     },
251 	{ NCSI_PKT_CMD_EBF,    4, ncsi_cmd_handler_ebf     },
252 	{ NCSI_PKT_CMD_DBF,    0, ncsi_cmd_handler_default },
253 	{ NCSI_PKT_CMD_EGMF,   4, ncsi_cmd_handler_egmf    },
254 	{ NCSI_PKT_CMD_DGMF,   0, ncsi_cmd_handler_default },
255 	{ NCSI_PKT_CMD_SNFC,   4, ncsi_cmd_handler_snfc    },
256 	{ NCSI_PKT_CMD_GVI,    0, ncsi_cmd_handler_default },
257 	{ NCSI_PKT_CMD_GC,     0, ncsi_cmd_handler_default },
258 	{ NCSI_PKT_CMD_GP,     0, ncsi_cmd_handler_default },
259 	{ NCSI_PKT_CMD_GCPS,   0, ncsi_cmd_handler_default },
260 	{ NCSI_PKT_CMD_GNS,    0, ncsi_cmd_handler_default },
261 	{ NCSI_PKT_CMD_GNPTS,  0, ncsi_cmd_handler_default },
262 	{ NCSI_PKT_CMD_GPS,    0, ncsi_cmd_handler_default },
263 	{ NCSI_PKT_CMD_OEM,   -1, ncsi_cmd_handler_oem     },
264 	{ NCSI_PKT_CMD_PLDM,   0, NULL                     },
265 	{ NCSI_PKT_CMD_GPUUID, 0, ncsi_cmd_handler_default }
266 };
267 
268 static struct ncsi_request *ncsi_alloc_command(struct ncsi_cmd_arg *nca)
269 {
270 	struct ncsi_dev_priv *ndp = nca->ndp;
271 	struct ncsi_dev *nd = &ndp->ndev;
272 	struct net_device *dev = nd->dev;
273 	int hlen = LL_RESERVED_SPACE(dev);
274 	int tlen = dev->needed_tailroom;
275 	int len = hlen + tlen;
276 	struct sk_buff *skb;
277 	struct ncsi_request *nr;
278 
279 	nr = ncsi_alloc_request(ndp, nca->req_flags);
280 	if (!nr)
281 		return NULL;
282 
283 	/* NCSI command packet has 16-bytes header, payload, 4 bytes checksum.
284 	 * The packet needs padding if its payload is less than 26 bytes to
285 	 * meet 64 bytes minimal ethernet frame length.
286 	 */
287 	len += sizeof(struct ncsi_cmd_pkt_hdr) + 4;
288 	if (nca->payload < 26)
289 		len += 26;
290 	else
291 		len += nca->payload;
292 
293 	/* Allocate skb */
294 	skb = alloc_skb(len, GFP_ATOMIC);
295 	if (!skb) {
296 		ncsi_free_request(nr);
297 		return NULL;
298 	}
299 
300 	nr->cmd = skb;
301 	skb_reserve(skb, hlen);
302 	skb_reset_network_header(skb);
303 
304 	skb->dev = dev;
305 	skb->protocol = htons(ETH_P_NCSI);
306 
307 	return nr;
308 }
309 
310 int ncsi_xmit_cmd(struct ncsi_cmd_arg *nca)
311 {
312 	struct ncsi_cmd_handler *nch = NULL;
313 	struct ncsi_request *nr;
314 	unsigned char type;
315 	struct ethhdr *eh;
316 	int i, ret;
317 
318 	/* Use OEM generic handler for Netlink request */
319 	if (nca->req_flags == NCSI_REQ_FLAG_NETLINK_DRIVEN)
320 		type = NCSI_PKT_CMD_OEM;
321 	else
322 		type = nca->type;
323 
324 	/* Search for the handler */
325 	for (i = 0; i < ARRAY_SIZE(ncsi_cmd_handlers); i++) {
326 		if (ncsi_cmd_handlers[i].type == type) {
327 			if (ncsi_cmd_handlers[i].handler)
328 				nch = &ncsi_cmd_handlers[i];
329 			else
330 				nch = NULL;
331 
332 			break;
333 		}
334 	}
335 
336 	if (!nch) {
337 		netdev_err(nca->ndp->ndev.dev,
338 			   "Cannot send packet with type 0x%02x\n", nca->type);
339 		return -ENOENT;
340 	}
341 
342 	/* Get packet payload length and allocate the request
343 	 * It is expected that if length set as negative in
344 	 * handler structure means caller is initializing it
345 	 * and setting length in nca before calling xmit function
346 	 */
347 	if (nch->payload >= 0)
348 		nca->payload = nch->payload;
349 	nr = ncsi_alloc_command(nca);
350 	if (!nr)
351 		return -ENOMEM;
352 
353 	/* track netlink information */
354 	if (nca->req_flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
355 		nr->snd_seq = nca->info->snd_seq;
356 		nr->snd_portid = nca->info->snd_portid;
357 		nr->nlhdr = *nca->info->nlhdr;
358 	}
359 
360 	/* Prepare the packet */
361 	nca->id = nr->id;
362 	ret = nch->handler(nr->cmd, nca);
363 	if (ret) {
364 		ncsi_free_request(nr);
365 		return ret;
366 	}
367 
368 	/* Fill the ethernet header */
369 	eh = skb_push(nr->cmd, sizeof(*eh));
370 	eh->h_proto = htons(ETH_P_NCSI);
371 	eth_broadcast_addr(eh->h_dest);
372 	eth_broadcast_addr(eh->h_source);
373 
374 	/* Start the timer for the request that might not have
375 	 * corresponding response. Given NCSI is an internal
376 	 * connection a 1 second delay should be sufficient.
377 	 */
378 	nr->enabled = true;
379 	mod_timer(&nr->timer, jiffies + 1 * HZ);
380 
381 	/* Send NCSI packet */
382 	skb_get(nr->cmd);
383 	ret = dev_queue_xmit(nr->cmd);
384 	if (ret < 0) {
385 		ncsi_free_request(nr);
386 		return ret;
387 	}
388 
389 	return 0;
390 }
391