xref: /openbmc/linux/drivers/net/ethernet/intel/ixgbe/ixgbe_ipsec.c (revision 05cf4fe738242183f1237f1b3a28b4479348c0a1)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 2017 Oracle and/or its affiliates. All rights reserved. */
3 
4 #include "ixgbe.h"
5 #include <net/xfrm.h>
6 #include <crypto/aead.h>
7 
8 #define IXGBE_IPSEC_KEY_BITS  160
9 static const char aes_gcm_name[] = "rfc4106(gcm(aes))";
10 
11 static void ixgbe_ipsec_del_sa(struct xfrm_state *xs);
12 
13 /**
14  * ixgbe_ipsec_set_tx_sa - set the Tx SA registers
15  * @hw: hw specific details
16  * @idx: register index to write
17  * @key: key byte array
18  * @salt: salt bytes
19  **/
20 static void ixgbe_ipsec_set_tx_sa(struct ixgbe_hw *hw, u16 idx,
21 				  u32 key[], u32 salt)
22 {
23 	u32 reg;
24 	int i;
25 
26 	for (i = 0; i < 4; i++)
27 		IXGBE_WRITE_REG(hw, IXGBE_IPSTXKEY(i),
28 				(__force u32)cpu_to_be32(key[3 - i]));
29 	IXGBE_WRITE_REG(hw, IXGBE_IPSTXSALT, (__force u32)cpu_to_be32(salt));
30 	IXGBE_WRITE_FLUSH(hw);
31 
32 	reg = IXGBE_READ_REG(hw, IXGBE_IPSTXIDX);
33 	reg &= IXGBE_RXTXIDX_IPS_EN;
34 	reg |= idx << IXGBE_RXTXIDX_IDX_SHIFT | IXGBE_RXTXIDX_WRITE;
35 	IXGBE_WRITE_REG(hw, IXGBE_IPSTXIDX, reg);
36 	IXGBE_WRITE_FLUSH(hw);
37 }
38 
39 /**
40  * ixgbe_ipsec_set_rx_item - set an Rx table item
41  * @hw: hw specific details
42  * @idx: register index to write
43  * @tbl: table selector
44  *
45  * Trigger the device to store into a particular Rx table the
46  * data that has already been loaded into the input register
47  **/
48 static void ixgbe_ipsec_set_rx_item(struct ixgbe_hw *hw, u16 idx,
49 				    enum ixgbe_ipsec_tbl_sel tbl)
50 {
51 	u32 reg;
52 
53 	reg = IXGBE_READ_REG(hw, IXGBE_IPSRXIDX);
54 	reg &= IXGBE_RXTXIDX_IPS_EN;
55 	reg |= tbl << IXGBE_RXIDX_TBL_SHIFT |
56 	       idx << IXGBE_RXTXIDX_IDX_SHIFT |
57 	       IXGBE_RXTXIDX_WRITE;
58 	IXGBE_WRITE_REG(hw, IXGBE_IPSRXIDX, reg);
59 	IXGBE_WRITE_FLUSH(hw);
60 }
61 
62 /**
63  * ixgbe_ipsec_set_rx_sa - set up the register bits to save SA info
64  * @hw: hw specific details
65  * @idx: register index to write
66  * @spi: security parameter index
67  * @key: key byte array
68  * @salt: salt bytes
69  * @mode: rx decrypt control bits
70  * @ip_idx: index into IP table for related IP address
71  **/
72 static void ixgbe_ipsec_set_rx_sa(struct ixgbe_hw *hw, u16 idx, __be32 spi,
73 				  u32 key[], u32 salt, u32 mode, u32 ip_idx)
74 {
75 	int i;
76 
77 	/* store the SPI (in bigendian) and IPidx */
78 	IXGBE_WRITE_REG(hw, IXGBE_IPSRXSPI,
79 			(__force u32)cpu_to_le32((__force u32)spi));
80 	IXGBE_WRITE_REG(hw, IXGBE_IPSRXIPIDX, ip_idx);
81 	IXGBE_WRITE_FLUSH(hw);
82 
83 	ixgbe_ipsec_set_rx_item(hw, idx, ips_rx_spi_tbl);
84 
85 	/* store the key, salt, and mode */
86 	for (i = 0; i < 4; i++)
87 		IXGBE_WRITE_REG(hw, IXGBE_IPSRXKEY(i),
88 				(__force u32)cpu_to_be32(key[3 - i]));
89 	IXGBE_WRITE_REG(hw, IXGBE_IPSRXSALT, (__force u32)cpu_to_be32(salt));
90 	IXGBE_WRITE_REG(hw, IXGBE_IPSRXMOD, mode);
91 	IXGBE_WRITE_FLUSH(hw);
92 
93 	ixgbe_ipsec_set_rx_item(hw, idx, ips_rx_key_tbl);
94 }
95 
96 /**
97  * ixgbe_ipsec_set_rx_ip - set up the register bits to save SA IP addr info
98  * @hw: hw specific details
99  * @idx: register index to write
100  * @addr: IP address byte array
101  **/
102 static void ixgbe_ipsec_set_rx_ip(struct ixgbe_hw *hw, u16 idx, __be32 addr[])
103 {
104 	int i;
105 
106 	/* store the ip address */
107 	for (i = 0; i < 4; i++)
108 		IXGBE_WRITE_REG(hw, IXGBE_IPSRXIPADDR(i),
109 				(__force u32)cpu_to_le32((__force u32)addr[i]));
110 	IXGBE_WRITE_FLUSH(hw);
111 
112 	ixgbe_ipsec_set_rx_item(hw, idx, ips_rx_ip_tbl);
113 }
114 
115 /**
116  * ixgbe_ipsec_clear_hw_tables - because some tables don't get cleared on reset
117  * @adapter: board private structure
118  **/
119 static void ixgbe_ipsec_clear_hw_tables(struct ixgbe_adapter *adapter)
120 {
121 	struct ixgbe_hw *hw = &adapter->hw;
122 	u32 buf[4] = {0, 0, 0, 0};
123 	u16 idx;
124 
125 	/* disable Rx and Tx SA lookup */
126 	IXGBE_WRITE_REG(hw, IXGBE_IPSRXIDX, 0);
127 	IXGBE_WRITE_REG(hw, IXGBE_IPSTXIDX, 0);
128 
129 	/* scrub the tables - split the loops for the max of the IP table */
130 	for (idx = 0; idx < IXGBE_IPSEC_MAX_RX_IP_COUNT; idx++) {
131 		ixgbe_ipsec_set_tx_sa(hw, idx, buf, 0);
132 		ixgbe_ipsec_set_rx_sa(hw, idx, 0, buf, 0, 0, 0);
133 		ixgbe_ipsec_set_rx_ip(hw, idx, (__be32 *)buf);
134 	}
135 	for (; idx < IXGBE_IPSEC_MAX_SA_COUNT; idx++) {
136 		ixgbe_ipsec_set_tx_sa(hw, idx, buf, 0);
137 		ixgbe_ipsec_set_rx_sa(hw, idx, 0, buf, 0, 0, 0);
138 	}
139 }
140 
141 /**
142  * ixgbe_ipsec_stop_data
143  * @adapter: board private structure
144  **/
145 static void ixgbe_ipsec_stop_data(struct ixgbe_adapter *adapter)
146 {
147 	struct ixgbe_hw *hw = &adapter->hw;
148 	bool link = adapter->link_up;
149 	u32 t_rdy, r_rdy;
150 	u32 limit;
151 	u32 reg;
152 
153 	/* halt data paths */
154 	reg = IXGBE_READ_REG(hw, IXGBE_SECTXCTRL);
155 	reg |= IXGBE_SECTXCTRL_TX_DIS;
156 	IXGBE_WRITE_REG(hw, IXGBE_SECTXCTRL, reg);
157 
158 	reg = IXGBE_READ_REG(hw, IXGBE_SECRXCTRL);
159 	reg |= IXGBE_SECRXCTRL_RX_DIS;
160 	IXGBE_WRITE_REG(hw, IXGBE_SECRXCTRL, reg);
161 
162 	/* If both Tx and Rx are ready there are no packets
163 	 * that we need to flush so the loopback configuration
164 	 * below is not necessary.
165 	 */
166 	t_rdy = IXGBE_READ_REG(hw, IXGBE_SECTXSTAT) &
167 		IXGBE_SECTXSTAT_SECTX_RDY;
168 	r_rdy = IXGBE_READ_REG(hw, IXGBE_SECRXSTAT) &
169 		IXGBE_SECRXSTAT_SECRX_RDY;
170 	if (t_rdy && r_rdy)
171 		return;
172 
173 	/* If the tx fifo doesn't have link, but still has data,
174 	 * we can't clear the tx sec block.  Set the MAC loopback
175 	 * before block clear
176 	 */
177 	if (!link) {
178 		reg = IXGBE_READ_REG(hw, IXGBE_MACC);
179 		reg |= IXGBE_MACC_FLU;
180 		IXGBE_WRITE_REG(hw, IXGBE_MACC, reg);
181 
182 		reg = IXGBE_READ_REG(hw, IXGBE_HLREG0);
183 		reg |= IXGBE_HLREG0_LPBK;
184 		IXGBE_WRITE_REG(hw, IXGBE_HLREG0, reg);
185 
186 		IXGBE_WRITE_FLUSH(hw);
187 		mdelay(3);
188 	}
189 
190 	/* wait for the paths to empty */
191 	limit = 20;
192 	do {
193 		mdelay(10);
194 		t_rdy = IXGBE_READ_REG(hw, IXGBE_SECTXSTAT) &
195 			IXGBE_SECTXSTAT_SECTX_RDY;
196 		r_rdy = IXGBE_READ_REG(hw, IXGBE_SECRXSTAT) &
197 			IXGBE_SECRXSTAT_SECRX_RDY;
198 	} while (!(t_rdy && r_rdy) && limit--);
199 
200 	/* undo loopback if we played with it earlier */
201 	if (!link) {
202 		reg = IXGBE_READ_REG(hw, IXGBE_MACC);
203 		reg &= ~IXGBE_MACC_FLU;
204 		IXGBE_WRITE_REG(hw, IXGBE_MACC, reg);
205 
206 		reg = IXGBE_READ_REG(hw, IXGBE_HLREG0);
207 		reg &= ~IXGBE_HLREG0_LPBK;
208 		IXGBE_WRITE_REG(hw, IXGBE_HLREG0, reg);
209 
210 		IXGBE_WRITE_FLUSH(hw);
211 	}
212 }
213 
214 /**
215  * ixgbe_ipsec_stop_engine
216  * @adapter: board private structure
217  **/
218 static void ixgbe_ipsec_stop_engine(struct ixgbe_adapter *adapter)
219 {
220 	struct ixgbe_hw *hw = &adapter->hw;
221 	u32 reg;
222 
223 	ixgbe_ipsec_stop_data(adapter);
224 
225 	/* disable Rx and Tx SA lookup */
226 	IXGBE_WRITE_REG(hw, IXGBE_IPSTXIDX, 0);
227 	IXGBE_WRITE_REG(hw, IXGBE_IPSRXIDX, 0);
228 
229 	/* disable the Rx and Tx engines and full packet store-n-forward */
230 	reg = IXGBE_READ_REG(hw, IXGBE_SECTXCTRL);
231 	reg |= IXGBE_SECTXCTRL_SECTX_DIS;
232 	reg &= ~IXGBE_SECTXCTRL_STORE_FORWARD;
233 	IXGBE_WRITE_REG(hw, IXGBE_SECTXCTRL, reg);
234 
235 	reg = IXGBE_READ_REG(hw, IXGBE_SECRXCTRL);
236 	reg |= IXGBE_SECRXCTRL_SECRX_DIS;
237 	IXGBE_WRITE_REG(hw, IXGBE_SECRXCTRL, reg);
238 
239 	/* restore the "tx security buffer almost full threshold" to 0x250 */
240 	IXGBE_WRITE_REG(hw, IXGBE_SECTXBUFFAF, 0x250);
241 
242 	/* Set minimum IFG between packets back to the default 0x1 */
243 	reg = IXGBE_READ_REG(hw, IXGBE_SECTXMINIFG);
244 	reg = (reg & 0xfffffff0) | 0x1;
245 	IXGBE_WRITE_REG(hw, IXGBE_SECTXMINIFG, reg);
246 
247 	/* final set for normal (no ipsec offload) processing */
248 	IXGBE_WRITE_REG(hw, IXGBE_SECTXCTRL, IXGBE_SECTXCTRL_SECTX_DIS);
249 	IXGBE_WRITE_REG(hw, IXGBE_SECRXCTRL, IXGBE_SECRXCTRL_SECRX_DIS);
250 
251 	IXGBE_WRITE_FLUSH(hw);
252 }
253 
254 /**
255  * ixgbe_ipsec_start_engine
256  * @adapter: board private structure
257  *
258  * NOTE: this increases power consumption whether being used or not
259  **/
260 static void ixgbe_ipsec_start_engine(struct ixgbe_adapter *adapter)
261 {
262 	struct ixgbe_hw *hw = &adapter->hw;
263 	u32 reg;
264 
265 	ixgbe_ipsec_stop_data(adapter);
266 
267 	/* Set minimum IFG between packets to 3 */
268 	reg = IXGBE_READ_REG(hw, IXGBE_SECTXMINIFG);
269 	reg = (reg & 0xfffffff0) | 0x3;
270 	IXGBE_WRITE_REG(hw, IXGBE_SECTXMINIFG, reg);
271 
272 	/* Set "tx security buffer almost full threshold" to 0x15 so that the
273 	 * almost full indication is generated only after buffer contains at
274 	 * least an entire jumbo packet.
275 	 */
276 	reg = IXGBE_READ_REG(hw, IXGBE_SECTXBUFFAF);
277 	reg = (reg & 0xfffffc00) | 0x15;
278 	IXGBE_WRITE_REG(hw, IXGBE_SECTXBUFFAF, reg);
279 
280 	/* restart the data paths by clearing the DISABLE bits */
281 	IXGBE_WRITE_REG(hw, IXGBE_SECRXCTRL, 0);
282 	IXGBE_WRITE_REG(hw, IXGBE_SECTXCTRL, IXGBE_SECTXCTRL_STORE_FORWARD);
283 
284 	/* enable Rx and Tx SA lookup */
285 	IXGBE_WRITE_REG(hw, IXGBE_IPSTXIDX, IXGBE_RXTXIDX_IPS_EN);
286 	IXGBE_WRITE_REG(hw, IXGBE_IPSRXIDX, IXGBE_RXTXIDX_IPS_EN);
287 
288 	IXGBE_WRITE_FLUSH(hw);
289 }
290 
291 /**
292  * ixgbe_ipsec_restore - restore the ipsec HW settings after a reset
293  * @adapter: board private structure
294  *
295  * Reload the HW tables from the SW tables after they've been bashed
296  * by a chip reset.
297  *
298  * Any VF entries are removed from the SW and HW tables since either
299  * (a) the VF also gets reset on PF reset and will ask again for the
300  * offloads, or (b) the VF has been removed by a change in the num_vfs.
301  **/
302 void ixgbe_ipsec_restore(struct ixgbe_adapter *adapter)
303 {
304 	struct ixgbe_ipsec *ipsec = adapter->ipsec;
305 	struct ixgbe_hw *hw = &adapter->hw;
306 	int i;
307 
308 	if (!(adapter->flags2 & IXGBE_FLAG2_IPSEC_ENABLED))
309 		return;
310 
311 	/* clean up and restart the engine */
312 	ixgbe_ipsec_stop_engine(adapter);
313 	ixgbe_ipsec_clear_hw_tables(adapter);
314 	ixgbe_ipsec_start_engine(adapter);
315 
316 	/* reload the Rx and Tx keys */
317 	for (i = 0; i < IXGBE_IPSEC_MAX_SA_COUNT; i++) {
318 		struct rx_sa *r = &ipsec->rx_tbl[i];
319 		struct tx_sa *t = &ipsec->tx_tbl[i];
320 
321 		if (r->used) {
322 			if (r->mode & IXGBE_RXTXMOD_VF)
323 				ixgbe_ipsec_del_sa(r->xs);
324 			else
325 				ixgbe_ipsec_set_rx_sa(hw, i, r->xs->id.spi,
326 						      r->key, r->salt,
327 						      r->mode, r->iptbl_ind);
328 		}
329 
330 		if (t->used) {
331 			if (t->mode & IXGBE_RXTXMOD_VF)
332 				ixgbe_ipsec_del_sa(t->xs);
333 			else
334 				ixgbe_ipsec_set_tx_sa(hw, i, t->key, t->salt);
335 		}
336 	}
337 
338 	/* reload the IP addrs */
339 	for (i = 0; i < IXGBE_IPSEC_MAX_RX_IP_COUNT; i++) {
340 		struct rx_ip_sa *ipsa = &ipsec->ip_tbl[i];
341 
342 		if (ipsa->used)
343 			ixgbe_ipsec_set_rx_ip(hw, i, ipsa->ipaddr);
344 	}
345 }
346 
347 /**
348  * ixgbe_ipsec_find_empty_idx - find the first unused security parameter index
349  * @ipsec: pointer to ipsec struct
350  * @rxtable: true if we need to look in the Rx table
351  *
352  * Returns the first unused index in either the Rx or Tx SA table
353  **/
354 static int ixgbe_ipsec_find_empty_idx(struct ixgbe_ipsec *ipsec, bool rxtable)
355 {
356 	u32 i;
357 
358 	if (rxtable) {
359 		if (ipsec->num_rx_sa == IXGBE_IPSEC_MAX_SA_COUNT)
360 			return -ENOSPC;
361 
362 		/* search rx sa table */
363 		for (i = 0; i < IXGBE_IPSEC_MAX_SA_COUNT; i++) {
364 			if (!ipsec->rx_tbl[i].used)
365 				return i;
366 		}
367 	} else {
368 		if (ipsec->num_tx_sa == IXGBE_IPSEC_MAX_SA_COUNT)
369 			return -ENOSPC;
370 
371 		/* search tx sa table */
372 		for (i = 0; i < IXGBE_IPSEC_MAX_SA_COUNT; i++) {
373 			if (!ipsec->tx_tbl[i].used)
374 				return i;
375 		}
376 	}
377 
378 	return -ENOSPC;
379 }
380 
381 /**
382  * ixgbe_ipsec_find_rx_state - find the state that matches
383  * @ipsec: pointer to ipsec struct
384  * @daddr: inbound address to match
385  * @proto: protocol to match
386  * @spi: SPI to match
387  * @ip4: true if using an ipv4 address
388  *
389  * Returns a pointer to the matching SA state information
390  **/
391 static struct xfrm_state *ixgbe_ipsec_find_rx_state(struct ixgbe_ipsec *ipsec,
392 						    __be32 *daddr, u8 proto,
393 						    __be32 spi, bool ip4)
394 {
395 	struct rx_sa *rsa;
396 	struct xfrm_state *ret = NULL;
397 
398 	rcu_read_lock();
399 	hash_for_each_possible_rcu(ipsec->rx_sa_list, rsa, hlist,
400 				   (__force u32)spi) {
401 		if (rsa->mode & IXGBE_RXTXMOD_VF)
402 			continue;
403 		if (spi == rsa->xs->id.spi &&
404 		    ((ip4 && *daddr == rsa->xs->id.daddr.a4) ||
405 		      (!ip4 && !memcmp(daddr, &rsa->xs->id.daddr.a6,
406 				       sizeof(rsa->xs->id.daddr.a6)))) &&
407 		    proto == rsa->xs->id.proto) {
408 			ret = rsa->xs;
409 			xfrm_state_hold(ret);
410 			break;
411 		}
412 	}
413 	rcu_read_unlock();
414 	return ret;
415 }
416 
417 /**
418  * ixgbe_ipsec_parse_proto_keys - find the key and salt based on the protocol
419  * @xs: pointer to xfrm_state struct
420  * @mykey: pointer to key array to populate
421  * @mysalt: pointer to salt value to populate
422  *
423  * This copies the protocol keys and salt to our own data tables.  The
424  * 82599 family only supports the one algorithm.
425  **/
426 static int ixgbe_ipsec_parse_proto_keys(struct xfrm_state *xs,
427 					u32 *mykey, u32 *mysalt)
428 {
429 	struct net_device *dev = xs->xso.dev;
430 	unsigned char *key_data;
431 	char *alg_name = NULL;
432 	int key_len;
433 
434 	if (!xs->aead) {
435 		netdev_err(dev, "Unsupported IPsec algorithm\n");
436 		return -EINVAL;
437 	}
438 
439 	if (xs->aead->alg_icv_len != IXGBE_IPSEC_AUTH_BITS) {
440 		netdev_err(dev, "IPsec offload requires %d bit authentication\n",
441 			   IXGBE_IPSEC_AUTH_BITS);
442 		return -EINVAL;
443 	}
444 
445 	key_data = &xs->aead->alg_key[0];
446 	key_len = xs->aead->alg_key_len;
447 	alg_name = xs->aead->alg_name;
448 
449 	if (strcmp(alg_name, aes_gcm_name)) {
450 		netdev_err(dev, "Unsupported IPsec algorithm - please use %s\n",
451 			   aes_gcm_name);
452 		return -EINVAL;
453 	}
454 
455 	/* The key bytes come down in a bigendian array of bytes, so
456 	 * we don't need to do any byteswapping.
457 	 * 160 accounts for 16 byte key and 4 byte salt
458 	 */
459 	if (key_len == IXGBE_IPSEC_KEY_BITS) {
460 		*mysalt = ((u32 *)key_data)[4];
461 	} else if (key_len != (IXGBE_IPSEC_KEY_BITS - (sizeof(*mysalt) * 8))) {
462 		netdev_err(dev, "IPsec hw offload only supports keys up to 128 bits with a 32 bit salt\n");
463 		return -EINVAL;
464 	} else {
465 		netdev_info(dev, "IPsec hw offload parameters missing 32 bit salt value\n");
466 		*mysalt = 0;
467 	}
468 	memcpy(mykey, key_data, 16);
469 
470 	return 0;
471 }
472 
473 /**
474  * ixgbe_ipsec_check_mgmt_ip - make sure there is no clash with mgmt IP filters
475  * @xs: pointer to transformer state struct
476  **/
477 static int ixgbe_ipsec_check_mgmt_ip(struct xfrm_state *xs)
478 {
479 	struct net_device *dev = xs->xso.dev;
480 	struct ixgbe_adapter *adapter = netdev_priv(dev);
481 	struct ixgbe_hw *hw = &adapter->hw;
482 	u32 mfval, manc, reg;
483 	int num_filters = 4;
484 	bool manc_ipv4;
485 	u32 bmcipval;
486 	int i, j;
487 
488 #define MANC_EN_IPV4_FILTER      BIT(24)
489 #define MFVAL_IPV4_FILTER_SHIFT  16
490 #define MFVAL_IPV6_FILTER_SHIFT  24
491 #define MIPAF_ARR(_m, _n)        (IXGBE_MIPAF + ((_m) * 0x10) + ((_n) * 4))
492 
493 #define IXGBE_BMCIP(_n)          (0x5050 + ((_n) * 4))
494 #define IXGBE_BMCIPVAL           0x5060
495 #define BMCIP_V4                 0x2
496 #define BMCIP_V6                 0x3
497 #define BMCIP_MASK               0x3
498 
499 	manc = IXGBE_READ_REG(hw, IXGBE_MANC);
500 	manc_ipv4 = !!(manc & MANC_EN_IPV4_FILTER);
501 	mfval = IXGBE_READ_REG(hw, IXGBE_MFVAL);
502 	bmcipval = IXGBE_READ_REG(hw, IXGBE_BMCIPVAL);
503 
504 	if (xs->props.family == AF_INET) {
505 		/* are there any IPv4 filters to check? */
506 		if (manc_ipv4) {
507 			/* the 4 ipv4 filters are all in MIPAF(3, i) */
508 			for (i = 0; i < num_filters; i++) {
509 				if (!(mfval & BIT(MFVAL_IPV4_FILTER_SHIFT + i)))
510 					continue;
511 
512 				reg = IXGBE_READ_REG(hw, MIPAF_ARR(3, i));
513 				if (reg == xs->id.daddr.a4)
514 					return 1;
515 			}
516 		}
517 
518 		if ((bmcipval & BMCIP_MASK) == BMCIP_V4) {
519 			reg = IXGBE_READ_REG(hw, IXGBE_BMCIP(3));
520 			if (reg == xs->id.daddr.a4)
521 				return 1;
522 		}
523 
524 	} else {
525 		/* if there are ipv4 filters, they are in the last ipv6 slot */
526 		if (manc_ipv4)
527 			num_filters = 3;
528 
529 		for (i = 0; i < num_filters; i++) {
530 			if (!(mfval & BIT(MFVAL_IPV6_FILTER_SHIFT + i)))
531 				continue;
532 
533 			for (j = 0; j < 4; j++) {
534 				reg = IXGBE_READ_REG(hw, MIPAF_ARR(i, j));
535 				if (reg != xs->id.daddr.a6[j])
536 					break;
537 			}
538 			if (j == 4)   /* did we match all 4 words? */
539 				return 1;
540 		}
541 
542 		if ((bmcipval & BMCIP_MASK) == BMCIP_V6) {
543 			for (j = 0; j < 4; j++) {
544 				reg = IXGBE_READ_REG(hw, IXGBE_BMCIP(j));
545 				if (reg != xs->id.daddr.a6[j])
546 					break;
547 			}
548 			if (j == 4)   /* did we match all 4 words? */
549 				return 1;
550 		}
551 	}
552 
553 	return 0;
554 }
555 
556 /**
557  * ixgbe_ipsec_add_sa - program device with a security association
558  * @xs: pointer to transformer state struct
559  **/
560 static int ixgbe_ipsec_add_sa(struct xfrm_state *xs)
561 {
562 	struct net_device *dev = xs->xso.dev;
563 	struct ixgbe_adapter *adapter = netdev_priv(dev);
564 	struct ixgbe_ipsec *ipsec = adapter->ipsec;
565 	struct ixgbe_hw *hw = &adapter->hw;
566 	int checked, match, first;
567 	u16 sa_idx;
568 	int ret;
569 	int i;
570 
571 	if (xs->id.proto != IPPROTO_ESP && xs->id.proto != IPPROTO_AH) {
572 		netdev_err(dev, "Unsupported protocol 0x%04x for ipsec offload\n",
573 			   xs->id.proto);
574 		return -EINVAL;
575 	}
576 
577 	if (ixgbe_ipsec_check_mgmt_ip(xs)) {
578 		netdev_err(dev, "IPsec IP addr clash with mgmt filters\n");
579 		return -EINVAL;
580 	}
581 
582 	if (xs->xso.flags & XFRM_OFFLOAD_INBOUND) {
583 		struct rx_sa rsa;
584 
585 		if (xs->calg) {
586 			netdev_err(dev, "Compression offload not supported\n");
587 			return -EINVAL;
588 		}
589 
590 		/* find the first unused index */
591 		ret = ixgbe_ipsec_find_empty_idx(ipsec, true);
592 		if (ret < 0) {
593 			netdev_err(dev, "No space for SA in Rx table!\n");
594 			return ret;
595 		}
596 		sa_idx = (u16)ret;
597 
598 		memset(&rsa, 0, sizeof(rsa));
599 		rsa.used = true;
600 		rsa.xs = xs;
601 
602 		if (rsa.xs->id.proto & IPPROTO_ESP)
603 			rsa.decrypt = xs->ealg || xs->aead;
604 
605 		/* get the key and salt */
606 		ret = ixgbe_ipsec_parse_proto_keys(xs, rsa.key, &rsa.salt);
607 		if (ret) {
608 			netdev_err(dev, "Failed to get key data for Rx SA table\n");
609 			return ret;
610 		}
611 
612 		/* get ip for rx sa table */
613 		if (xs->props.family == AF_INET6)
614 			memcpy(rsa.ipaddr, &xs->id.daddr.a6, 16);
615 		else
616 			memcpy(&rsa.ipaddr[3], &xs->id.daddr.a4, 4);
617 
618 		/* The HW does not have a 1:1 mapping from keys to IP addrs, so
619 		 * check for a matching IP addr entry in the table.  If the addr
620 		 * already exists, use it; else find an unused slot and add the
621 		 * addr.  If one does not exist and there are no unused table
622 		 * entries, fail the request.
623 		 */
624 
625 		/* Find an existing match or first not used, and stop looking
626 		 * after we've checked all we know we have.
627 		 */
628 		checked = 0;
629 		match = -1;
630 		first = -1;
631 		for (i = 0;
632 		     i < IXGBE_IPSEC_MAX_RX_IP_COUNT &&
633 		     (checked < ipsec->num_rx_sa || first < 0);
634 		     i++) {
635 			if (ipsec->ip_tbl[i].used) {
636 				if (!memcmp(ipsec->ip_tbl[i].ipaddr,
637 					    rsa.ipaddr, sizeof(rsa.ipaddr))) {
638 					match = i;
639 					break;
640 				}
641 				checked++;
642 			} else if (first < 0) {
643 				first = i;  /* track the first empty seen */
644 			}
645 		}
646 
647 		if (ipsec->num_rx_sa == 0)
648 			first = 0;
649 
650 		if (match >= 0) {
651 			/* addrs are the same, we should use this one */
652 			rsa.iptbl_ind = match;
653 			ipsec->ip_tbl[match].ref_cnt++;
654 
655 		} else if (first >= 0) {
656 			/* no matches, but here's an empty slot */
657 			rsa.iptbl_ind = first;
658 
659 			memcpy(ipsec->ip_tbl[first].ipaddr,
660 			       rsa.ipaddr, sizeof(rsa.ipaddr));
661 			ipsec->ip_tbl[first].ref_cnt = 1;
662 			ipsec->ip_tbl[first].used = true;
663 
664 			ixgbe_ipsec_set_rx_ip(hw, rsa.iptbl_ind, rsa.ipaddr);
665 
666 		} else {
667 			/* no match and no empty slot */
668 			netdev_err(dev, "No space for SA in Rx IP SA table\n");
669 			memset(&rsa, 0, sizeof(rsa));
670 			return -ENOSPC;
671 		}
672 
673 		rsa.mode = IXGBE_RXMOD_VALID;
674 		if (rsa.xs->id.proto & IPPROTO_ESP)
675 			rsa.mode |= IXGBE_RXMOD_PROTO_ESP;
676 		if (rsa.decrypt)
677 			rsa.mode |= IXGBE_RXMOD_DECRYPT;
678 		if (rsa.xs->props.family == AF_INET6)
679 			rsa.mode |= IXGBE_RXMOD_IPV6;
680 
681 		/* the preparations worked, so save the info */
682 		memcpy(&ipsec->rx_tbl[sa_idx], &rsa, sizeof(rsa));
683 
684 		ixgbe_ipsec_set_rx_sa(hw, sa_idx, rsa.xs->id.spi, rsa.key,
685 				      rsa.salt, rsa.mode, rsa.iptbl_ind);
686 		xs->xso.offload_handle = sa_idx + IXGBE_IPSEC_BASE_RX_INDEX;
687 
688 		ipsec->num_rx_sa++;
689 
690 		/* hash the new entry for faster search in Rx path */
691 		hash_add_rcu(ipsec->rx_sa_list, &ipsec->rx_tbl[sa_idx].hlist,
692 			     (__force u32)rsa.xs->id.spi);
693 	} else {
694 		struct tx_sa tsa;
695 
696 		if (adapter->num_vfs)
697 			return -EOPNOTSUPP;
698 
699 		/* find the first unused index */
700 		ret = ixgbe_ipsec_find_empty_idx(ipsec, false);
701 		if (ret < 0) {
702 			netdev_err(dev, "No space for SA in Tx table\n");
703 			return ret;
704 		}
705 		sa_idx = (u16)ret;
706 
707 		memset(&tsa, 0, sizeof(tsa));
708 		tsa.used = true;
709 		tsa.xs = xs;
710 
711 		if (xs->id.proto & IPPROTO_ESP)
712 			tsa.encrypt = xs->ealg || xs->aead;
713 
714 		ret = ixgbe_ipsec_parse_proto_keys(xs, tsa.key, &tsa.salt);
715 		if (ret) {
716 			netdev_err(dev, "Failed to get key data for Tx SA table\n");
717 			memset(&tsa, 0, sizeof(tsa));
718 			return ret;
719 		}
720 
721 		/* the preparations worked, so save the info */
722 		memcpy(&ipsec->tx_tbl[sa_idx], &tsa, sizeof(tsa));
723 
724 		ixgbe_ipsec_set_tx_sa(hw, sa_idx, tsa.key, tsa.salt);
725 
726 		xs->xso.offload_handle = sa_idx + IXGBE_IPSEC_BASE_TX_INDEX;
727 
728 		ipsec->num_tx_sa++;
729 	}
730 
731 	/* enable the engine if not already warmed up */
732 	if (!(adapter->flags2 & IXGBE_FLAG2_IPSEC_ENABLED)) {
733 		ixgbe_ipsec_start_engine(adapter);
734 		adapter->flags2 |= IXGBE_FLAG2_IPSEC_ENABLED;
735 	}
736 
737 	return 0;
738 }
739 
740 /**
741  * ixgbe_ipsec_del_sa - clear out this specific SA
742  * @xs: pointer to transformer state struct
743  **/
744 static void ixgbe_ipsec_del_sa(struct xfrm_state *xs)
745 {
746 	struct net_device *dev = xs->xso.dev;
747 	struct ixgbe_adapter *adapter = netdev_priv(dev);
748 	struct ixgbe_ipsec *ipsec = adapter->ipsec;
749 	struct ixgbe_hw *hw = &adapter->hw;
750 	u32 zerobuf[4] = {0, 0, 0, 0};
751 	u16 sa_idx;
752 
753 	if (xs->xso.flags & XFRM_OFFLOAD_INBOUND) {
754 		struct rx_sa *rsa;
755 		u8 ipi;
756 
757 		sa_idx = xs->xso.offload_handle - IXGBE_IPSEC_BASE_RX_INDEX;
758 		rsa = &ipsec->rx_tbl[sa_idx];
759 
760 		if (!rsa->used) {
761 			netdev_err(dev, "Invalid Rx SA selected sa_idx=%d offload_handle=%lu\n",
762 				   sa_idx, xs->xso.offload_handle);
763 			return;
764 		}
765 
766 		ixgbe_ipsec_set_rx_sa(hw, sa_idx, 0, zerobuf, 0, 0, 0);
767 		hash_del_rcu(&rsa->hlist);
768 
769 		/* if the IP table entry is referenced by only this SA,
770 		 * i.e. ref_cnt is only 1, clear the IP table entry as well
771 		 */
772 		ipi = rsa->iptbl_ind;
773 		if (ipsec->ip_tbl[ipi].ref_cnt > 0) {
774 			ipsec->ip_tbl[ipi].ref_cnt--;
775 
776 			if (!ipsec->ip_tbl[ipi].ref_cnt) {
777 				memset(&ipsec->ip_tbl[ipi], 0,
778 				       sizeof(struct rx_ip_sa));
779 				ixgbe_ipsec_set_rx_ip(hw, ipi,
780 						      (__force __be32 *)zerobuf);
781 			}
782 		}
783 
784 		memset(rsa, 0, sizeof(struct rx_sa));
785 		ipsec->num_rx_sa--;
786 	} else {
787 		sa_idx = xs->xso.offload_handle - IXGBE_IPSEC_BASE_TX_INDEX;
788 
789 		if (!ipsec->tx_tbl[sa_idx].used) {
790 			netdev_err(dev, "Invalid Tx SA selected sa_idx=%d offload_handle=%lu\n",
791 				   sa_idx, xs->xso.offload_handle);
792 			return;
793 		}
794 
795 		ixgbe_ipsec_set_tx_sa(hw, sa_idx, zerobuf, 0);
796 		memset(&ipsec->tx_tbl[sa_idx], 0, sizeof(struct tx_sa));
797 		ipsec->num_tx_sa--;
798 	}
799 
800 	/* if there are no SAs left, stop the engine to save energy */
801 	if (ipsec->num_rx_sa == 0 && ipsec->num_tx_sa == 0) {
802 		adapter->flags2 &= ~IXGBE_FLAG2_IPSEC_ENABLED;
803 		ixgbe_ipsec_stop_engine(adapter);
804 	}
805 }
806 
807 /**
808  * ixgbe_ipsec_offload_ok - can this packet use the xfrm hw offload
809  * @skb: current data packet
810  * @xs: pointer to transformer state struct
811  **/
812 static bool ixgbe_ipsec_offload_ok(struct sk_buff *skb, struct xfrm_state *xs)
813 {
814 	if (xs->props.family == AF_INET) {
815 		/* Offload with IPv4 options is not supported yet */
816 		if (ip_hdr(skb)->ihl != 5)
817 			return false;
818 	} else {
819 		/* Offload with IPv6 extension headers is not support yet */
820 		if (ipv6_ext_hdr(ipv6_hdr(skb)->nexthdr))
821 			return false;
822 	}
823 
824 	return true;
825 }
826 
827 static const struct xfrmdev_ops ixgbe_xfrmdev_ops = {
828 	.xdo_dev_state_add = ixgbe_ipsec_add_sa,
829 	.xdo_dev_state_delete = ixgbe_ipsec_del_sa,
830 	.xdo_dev_offload_ok = ixgbe_ipsec_offload_ok,
831 };
832 
833 /**
834  * ixgbe_ipsec_vf_clear - clear the tables of data for a VF
835  * @adapter: board private structure
836  * @vf: VF id to be removed
837  **/
838 void ixgbe_ipsec_vf_clear(struct ixgbe_adapter *adapter, u32 vf)
839 {
840 	struct ixgbe_ipsec *ipsec = adapter->ipsec;
841 	int i;
842 
843 	/* search rx sa table */
844 	for (i = 0; i < IXGBE_IPSEC_MAX_SA_COUNT && ipsec->num_rx_sa; i++) {
845 		if (!ipsec->rx_tbl[i].used)
846 			continue;
847 		if (ipsec->rx_tbl[i].mode & IXGBE_RXTXMOD_VF &&
848 		    ipsec->rx_tbl[i].vf == vf)
849 			ixgbe_ipsec_del_sa(ipsec->rx_tbl[i].xs);
850 	}
851 
852 	/* search tx sa table */
853 	for (i = 0; i < IXGBE_IPSEC_MAX_SA_COUNT && ipsec->num_tx_sa; i++) {
854 		if (!ipsec->tx_tbl[i].used)
855 			continue;
856 		if (ipsec->tx_tbl[i].mode & IXGBE_RXTXMOD_VF &&
857 		    ipsec->tx_tbl[i].vf == vf)
858 			ixgbe_ipsec_del_sa(ipsec->tx_tbl[i].xs);
859 	}
860 }
861 
862 /**
863  * ixgbe_ipsec_vf_add_sa - translate VF request to SA add
864  * @adapter: board private structure
865  * @msgbuf: The message buffer
866  * @vf: the VF index
867  *
868  * Make up a new xs and algorithm info from the data sent by the VF.
869  * We only need to sketch in just enough to set up the HW offload.
870  * Put the resulting offload_handle into the return message to the VF.
871  *
872  * Returns 0 or error value
873  **/
874 int ixgbe_ipsec_vf_add_sa(struct ixgbe_adapter *adapter, u32 *msgbuf, u32 vf)
875 {
876 	struct ixgbe_ipsec *ipsec = adapter->ipsec;
877 	struct xfrm_algo_desc *algo;
878 	struct sa_mbx_msg *sam;
879 	struct xfrm_state *xs;
880 	size_t aead_len;
881 	u16 sa_idx;
882 	u32 pfsa;
883 	int err;
884 
885 	sam = (struct sa_mbx_msg *)(&msgbuf[1]);
886 	if (!adapter->vfinfo[vf].trusted ||
887 	    !(adapter->flags2 & IXGBE_FLAG2_VF_IPSEC_ENABLED)) {
888 		e_warn(drv, "VF %d attempted to add an IPsec SA\n", vf);
889 		err = -EACCES;
890 		goto err_out;
891 	}
892 
893 	/* Tx IPsec offload doesn't seem to work on this
894 	 * device, so block these requests for now.
895 	 */
896 	if (!(sam->flags & XFRM_OFFLOAD_INBOUND)) {
897 		err = -EOPNOTSUPP;
898 		goto err_out;
899 	}
900 
901 	xs = kzalloc(sizeof(*xs), GFP_KERNEL);
902 	if (unlikely(!xs)) {
903 		err = -ENOMEM;
904 		goto err_out;
905 	}
906 
907 	xs->xso.flags = sam->flags;
908 	xs->id.spi = sam->spi;
909 	xs->id.proto = sam->proto;
910 	xs->props.family = sam->family;
911 	if (xs->props.family == AF_INET6)
912 		memcpy(&xs->id.daddr.a6, sam->addr, sizeof(xs->id.daddr.a6));
913 	else
914 		memcpy(&xs->id.daddr.a4, sam->addr, sizeof(xs->id.daddr.a4));
915 	xs->xso.dev = adapter->netdev;
916 
917 	algo = xfrm_aead_get_byname(aes_gcm_name, IXGBE_IPSEC_AUTH_BITS, 1);
918 	if (unlikely(!algo)) {
919 		err = -ENOENT;
920 		goto err_xs;
921 	}
922 
923 	aead_len = sizeof(*xs->aead) + IXGBE_IPSEC_KEY_BITS / 8;
924 	xs->aead = kzalloc(aead_len, GFP_KERNEL);
925 	if (unlikely(!xs->aead)) {
926 		err = -ENOMEM;
927 		goto err_xs;
928 	}
929 
930 	xs->props.ealgo = algo->desc.sadb_alg_id;
931 	xs->geniv = algo->uinfo.aead.geniv;
932 	xs->aead->alg_icv_len = IXGBE_IPSEC_AUTH_BITS;
933 	xs->aead->alg_key_len = IXGBE_IPSEC_KEY_BITS;
934 	memcpy(xs->aead->alg_key, sam->key, sizeof(sam->key));
935 	memcpy(xs->aead->alg_name, aes_gcm_name, sizeof(aes_gcm_name));
936 
937 	/* set up the HW offload */
938 	err = ixgbe_ipsec_add_sa(xs);
939 	if (err)
940 		goto err_aead;
941 
942 	pfsa = xs->xso.offload_handle;
943 	if (pfsa < IXGBE_IPSEC_BASE_TX_INDEX) {
944 		sa_idx = pfsa - IXGBE_IPSEC_BASE_RX_INDEX;
945 		ipsec->rx_tbl[sa_idx].vf = vf;
946 		ipsec->rx_tbl[sa_idx].mode |= IXGBE_RXTXMOD_VF;
947 	} else {
948 		sa_idx = pfsa - IXGBE_IPSEC_BASE_TX_INDEX;
949 		ipsec->tx_tbl[sa_idx].vf = vf;
950 		ipsec->tx_tbl[sa_idx].mode |= IXGBE_RXTXMOD_VF;
951 	}
952 
953 	msgbuf[1] = xs->xso.offload_handle;
954 
955 	return 0;
956 
957 err_aead:
958 	memset(xs->aead, 0, sizeof(*xs->aead));
959 	kfree(xs->aead);
960 err_xs:
961 	memset(xs, 0, sizeof(*xs));
962 	kfree(xs);
963 err_out:
964 	msgbuf[1] = err;
965 	return err;
966 }
967 
968 /**
969  * ixgbe_ipsec_vf_del_sa - translate VF request to SA delete
970  * @adapter: board private structure
971  * @msgbuf: The message buffer
972  * @vf: the VF index
973  *
974  * Given the offload_handle sent by the VF, look for the related SA table
975  * entry and use its xs field to call for a delete of the SA.
976  *
977  * Note: We silently ignore requests to delete entries that are already
978  *       set to unused because when a VF is set to "DOWN", the PF first
979  *       gets a reset and clears all the VF's entries; then the VF's
980  *       XFRM stack sends individual deletes for each entry, which the
981  *       reset already removed.  In the future it might be good to try to
982  *       optimize this so not so many unnecessary delete messages are sent.
983  *
984  * Returns 0 or error value
985  **/
986 int ixgbe_ipsec_vf_del_sa(struct ixgbe_adapter *adapter, u32 *msgbuf, u32 vf)
987 {
988 	struct ixgbe_ipsec *ipsec = adapter->ipsec;
989 	struct xfrm_state *xs;
990 	u32 pfsa = msgbuf[1];
991 	u16 sa_idx;
992 
993 	if (!adapter->vfinfo[vf].trusted) {
994 		e_err(drv, "vf %d attempted to delete an SA\n", vf);
995 		return -EPERM;
996 	}
997 
998 	if (pfsa < IXGBE_IPSEC_BASE_TX_INDEX) {
999 		struct rx_sa *rsa;
1000 
1001 		sa_idx = pfsa - IXGBE_IPSEC_BASE_RX_INDEX;
1002 		if (sa_idx >= IXGBE_IPSEC_MAX_SA_COUNT) {
1003 			e_err(drv, "vf %d SA index %d out of range\n",
1004 			      vf, sa_idx);
1005 			return -EINVAL;
1006 		}
1007 
1008 		rsa = &ipsec->rx_tbl[sa_idx];
1009 
1010 		if (!rsa->used)
1011 			return 0;
1012 
1013 		if (!(rsa->mode & IXGBE_RXTXMOD_VF) ||
1014 		    rsa->vf != vf) {
1015 			e_err(drv, "vf %d bad Rx SA index %d\n", vf, sa_idx);
1016 			return -ENOENT;
1017 		}
1018 
1019 		xs = ipsec->rx_tbl[sa_idx].xs;
1020 	} else {
1021 		struct tx_sa *tsa;
1022 
1023 		sa_idx = pfsa - IXGBE_IPSEC_BASE_TX_INDEX;
1024 		if (sa_idx >= IXGBE_IPSEC_MAX_SA_COUNT) {
1025 			e_err(drv, "vf %d SA index %d out of range\n",
1026 			      vf, sa_idx);
1027 			return -EINVAL;
1028 		}
1029 
1030 		tsa = &ipsec->tx_tbl[sa_idx];
1031 
1032 		if (!tsa->used)
1033 			return 0;
1034 
1035 		if (!(tsa->mode & IXGBE_RXTXMOD_VF) ||
1036 		    tsa->vf != vf) {
1037 			e_err(drv, "vf %d bad Tx SA index %d\n", vf, sa_idx);
1038 			return -ENOENT;
1039 		}
1040 
1041 		xs = ipsec->tx_tbl[sa_idx].xs;
1042 	}
1043 
1044 	ixgbe_ipsec_del_sa(xs);
1045 
1046 	/* remove the xs that was made-up in the add request */
1047 	memset(xs, 0, sizeof(*xs));
1048 	kfree(xs);
1049 
1050 	return 0;
1051 }
1052 
1053 /**
1054  * ixgbe_ipsec_tx - setup Tx flags for ipsec offload
1055  * @tx_ring: outgoing context
1056  * @first: current data packet
1057  * @itd: ipsec Tx data for later use in building context descriptor
1058  **/
1059 int ixgbe_ipsec_tx(struct ixgbe_ring *tx_ring,
1060 		   struct ixgbe_tx_buffer *first,
1061 		   struct ixgbe_ipsec_tx_data *itd)
1062 {
1063 	struct ixgbe_adapter *adapter = netdev_priv(tx_ring->netdev);
1064 	struct ixgbe_ipsec *ipsec = adapter->ipsec;
1065 	struct xfrm_state *xs;
1066 	struct tx_sa *tsa;
1067 
1068 	if (unlikely(!first->skb->sp->len)) {
1069 		netdev_err(tx_ring->netdev, "%s: no xfrm state len = %d\n",
1070 			   __func__, first->skb->sp->len);
1071 		return 0;
1072 	}
1073 
1074 	xs = xfrm_input_state(first->skb);
1075 	if (unlikely(!xs)) {
1076 		netdev_err(tx_ring->netdev, "%s: no xfrm_input_state() xs = %p\n",
1077 			   __func__, xs);
1078 		return 0;
1079 	}
1080 
1081 	itd->sa_idx = xs->xso.offload_handle - IXGBE_IPSEC_BASE_TX_INDEX;
1082 	if (unlikely(itd->sa_idx >= IXGBE_IPSEC_MAX_SA_COUNT)) {
1083 		netdev_err(tx_ring->netdev, "%s: bad sa_idx=%d handle=%lu\n",
1084 			   __func__, itd->sa_idx, xs->xso.offload_handle);
1085 		return 0;
1086 	}
1087 
1088 	tsa = &ipsec->tx_tbl[itd->sa_idx];
1089 	if (unlikely(!tsa->used)) {
1090 		netdev_err(tx_ring->netdev, "%s: unused sa_idx=%d\n",
1091 			   __func__, itd->sa_idx);
1092 		return 0;
1093 	}
1094 
1095 	first->tx_flags |= IXGBE_TX_FLAGS_IPSEC | IXGBE_TX_FLAGS_CC;
1096 
1097 	if (xs->id.proto == IPPROTO_ESP) {
1098 
1099 		itd->flags |= IXGBE_ADVTXD_TUCMD_IPSEC_TYPE_ESP |
1100 			      IXGBE_ADVTXD_TUCMD_L4T_TCP;
1101 		if (first->protocol == htons(ETH_P_IP))
1102 			itd->flags |= IXGBE_ADVTXD_TUCMD_IPV4;
1103 
1104 		/* The actual trailer length is authlen (16 bytes) plus
1105 		 * 2 bytes for the proto and the padlen values, plus
1106 		 * padlen bytes of padding.  This ends up not the same
1107 		 * as the static value found in xs->props.trailer_len (21).
1108 		 *
1109 		 * ... but if we're doing GSO, don't bother as the stack
1110 		 * doesn't add a trailer for those.
1111 		 */
1112 		if (!skb_is_gso(first->skb)) {
1113 			/* The "correct" way to get the auth length would be
1114 			 * to use
1115 			 *    authlen = crypto_aead_authsize(xs->data);
1116 			 * but since we know we only have one size to worry
1117 			 * about * we can let the compiler use the constant
1118 			 * and save us a few CPU cycles.
1119 			 */
1120 			const int authlen = IXGBE_IPSEC_AUTH_BITS / 8;
1121 			struct sk_buff *skb = first->skb;
1122 			u8 padlen;
1123 			int ret;
1124 
1125 			ret = skb_copy_bits(skb, skb->len - (authlen + 2),
1126 					    &padlen, 1);
1127 			if (unlikely(ret))
1128 				return 0;
1129 			itd->trailer_len = authlen + 2 + padlen;
1130 		}
1131 	}
1132 	if (tsa->encrypt)
1133 		itd->flags |= IXGBE_ADVTXD_TUCMD_IPSEC_ENCRYPT_EN;
1134 
1135 	return 1;
1136 }
1137 
1138 /**
1139  * ixgbe_ipsec_rx - decode ipsec bits from Rx descriptor
1140  * @rx_ring: receiving ring
1141  * @rx_desc: receive data descriptor
1142  * @skb: current data packet
1143  *
1144  * Determine if there was an ipsec encapsulation noticed, and if so set up
1145  * the resulting status for later in the receive stack.
1146  **/
1147 void ixgbe_ipsec_rx(struct ixgbe_ring *rx_ring,
1148 		    union ixgbe_adv_rx_desc *rx_desc,
1149 		    struct sk_buff *skb)
1150 {
1151 	struct ixgbe_adapter *adapter = netdev_priv(rx_ring->netdev);
1152 	__le16 pkt_info = rx_desc->wb.lower.lo_dword.hs_rss.pkt_info;
1153 	__le16 ipsec_pkt_types = cpu_to_le16(IXGBE_RXDADV_PKTTYPE_IPSEC_AH |
1154 					     IXGBE_RXDADV_PKTTYPE_IPSEC_ESP);
1155 	struct ixgbe_ipsec *ipsec = adapter->ipsec;
1156 	struct xfrm_offload *xo = NULL;
1157 	struct xfrm_state *xs = NULL;
1158 	struct ipv6hdr *ip6 = NULL;
1159 	struct iphdr *ip4 = NULL;
1160 	void *daddr;
1161 	__be32 spi;
1162 	u8 *c_hdr;
1163 	u8 proto;
1164 
1165 	/* Find the ip and crypto headers in the data.
1166 	 * We can assume no vlan header in the way, b/c the
1167 	 * hw won't recognize the IPsec packet and anyway the
1168 	 * currently vlan device doesn't support xfrm offload.
1169 	 */
1170 	if (pkt_info & cpu_to_le16(IXGBE_RXDADV_PKTTYPE_IPV4)) {
1171 		ip4 = (struct iphdr *)(skb->data + ETH_HLEN);
1172 		daddr = &ip4->daddr;
1173 		c_hdr = (u8 *)ip4 + ip4->ihl * 4;
1174 	} else if (pkt_info & cpu_to_le16(IXGBE_RXDADV_PKTTYPE_IPV6)) {
1175 		ip6 = (struct ipv6hdr *)(skb->data + ETH_HLEN);
1176 		daddr = &ip6->daddr;
1177 		c_hdr = (u8 *)ip6 + sizeof(struct ipv6hdr);
1178 	} else {
1179 		return;
1180 	}
1181 
1182 	switch (pkt_info & ipsec_pkt_types) {
1183 	case cpu_to_le16(IXGBE_RXDADV_PKTTYPE_IPSEC_AH):
1184 		spi = ((struct ip_auth_hdr *)c_hdr)->spi;
1185 		proto = IPPROTO_AH;
1186 		break;
1187 	case cpu_to_le16(IXGBE_RXDADV_PKTTYPE_IPSEC_ESP):
1188 		spi = ((struct ip_esp_hdr *)c_hdr)->spi;
1189 		proto = IPPROTO_ESP;
1190 		break;
1191 	default:
1192 		return;
1193 	}
1194 
1195 	xs = ixgbe_ipsec_find_rx_state(ipsec, daddr, proto, spi, !!ip4);
1196 	if (unlikely(!xs))
1197 		return;
1198 
1199 	skb->sp = secpath_dup(skb->sp);
1200 	if (unlikely(!skb->sp))
1201 		return;
1202 
1203 	skb->sp->xvec[skb->sp->len++] = xs;
1204 	skb->sp->olen++;
1205 	xo = xfrm_offload(skb);
1206 	xo->flags = CRYPTO_DONE;
1207 	xo->status = CRYPTO_SUCCESS;
1208 
1209 	adapter->rx_ipsec++;
1210 }
1211 
1212 /**
1213  * ixgbe_init_ipsec_offload - initialize security registers for IPSec operation
1214  * @adapter: board private structure
1215  **/
1216 void ixgbe_init_ipsec_offload(struct ixgbe_adapter *adapter)
1217 {
1218 	struct ixgbe_hw *hw = &adapter->hw;
1219 	struct ixgbe_ipsec *ipsec;
1220 	u32 t_dis, r_dis;
1221 	size_t size;
1222 
1223 	if (hw->mac.type == ixgbe_mac_82598EB)
1224 		return;
1225 
1226 	/* If there is no support for either Tx or Rx offload
1227 	 * we should not be advertising support for IPsec.
1228 	 */
1229 	t_dis = IXGBE_READ_REG(hw, IXGBE_SECTXSTAT) &
1230 		IXGBE_SECTXSTAT_SECTX_OFF_DIS;
1231 	r_dis = IXGBE_READ_REG(hw, IXGBE_SECRXSTAT) &
1232 		IXGBE_SECRXSTAT_SECRX_OFF_DIS;
1233 	if (t_dis || r_dis)
1234 		return;
1235 
1236 	ipsec = kzalloc(sizeof(*ipsec), GFP_KERNEL);
1237 	if (!ipsec)
1238 		goto err1;
1239 	hash_init(ipsec->rx_sa_list);
1240 
1241 	size = sizeof(struct rx_sa) * IXGBE_IPSEC_MAX_SA_COUNT;
1242 	ipsec->rx_tbl = kzalloc(size, GFP_KERNEL);
1243 	if (!ipsec->rx_tbl)
1244 		goto err2;
1245 
1246 	size = sizeof(struct tx_sa) * IXGBE_IPSEC_MAX_SA_COUNT;
1247 	ipsec->tx_tbl = kzalloc(size, GFP_KERNEL);
1248 	if (!ipsec->tx_tbl)
1249 		goto err2;
1250 
1251 	size = sizeof(struct rx_ip_sa) * IXGBE_IPSEC_MAX_RX_IP_COUNT;
1252 	ipsec->ip_tbl = kzalloc(size, GFP_KERNEL);
1253 	if (!ipsec->ip_tbl)
1254 		goto err2;
1255 
1256 	ipsec->num_rx_sa = 0;
1257 	ipsec->num_tx_sa = 0;
1258 
1259 	adapter->ipsec = ipsec;
1260 	ixgbe_ipsec_stop_engine(adapter);
1261 	ixgbe_ipsec_clear_hw_tables(adapter);
1262 
1263 	adapter->netdev->xfrmdev_ops = &ixgbe_xfrmdev_ops;
1264 
1265 	return;
1266 
1267 err2:
1268 	kfree(ipsec->ip_tbl);
1269 	kfree(ipsec->rx_tbl);
1270 	kfree(ipsec->tx_tbl);
1271 	kfree(ipsec);
1272 err1:
1273 	netdev_err(adapter->netdev, "Unable to allocate memory for SA tables");
1274 }
1275 
1276 /**
1277  * ixgbe_stop_ipsec_offload - tear down the ipsec offload
1278  * @adapter: board private structure
1279  **/
1280 void ixgbe_stop_ipsec_offload(struct ixgbe_adapter *adapter)
1281 {
1282 	struct ixgbe_ipsec *ipsec = adapter->ipsec;
1283 
1284 	adapter->ipsec = NULL;
1285 	if (ipsec) {
1286 		kfree(ipsec->ip_tbl);
1287 		kfree(ipsec->rx_tbl);
1288 		kfree(ipsec->tx_tbl);
1289 		kfree(ipsec);
1290 	}
1291 }
1292