[net-next-2.6.git] / net / caif / cfpkt_skbuff.c

/*
 * Copyright (C) ST-Ericsson AB 2010
 * Author:	Sjur Brendeland/sjur.brandeland@stericsson.com
 * License terms: GNU General Public License (GPL) version 2
 */

#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__

#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/hardirq.h>
#include <net/caif/cfpkt.h>

#define PKT_PREFIX  48
#define PKT_POSTFIX 2
#define PKT_LEN_WHEN_EXTENDING 128
#define PKT_ERROR(pkt, errmsg)		   \
do {					   \
	cfpkt_priv(pkt)->erronous = true;  \
	skb_reset_tail_pointer(&pkt->skb); \
	pr_warn(errmsg);		   \
} while (0)

struct cfpktq {
	struct sk_buff_head head;
	atomic_t count;
	/* Lock protects count updates */
	spinlock_t lock;
};

/*
 * net/caif/ is generic and does not
 * understand SKB, so we do this typecast
 */
struct cfpkt {
	struct sk_buff skb;
};

/* Private data inside SKB */
struct cfpkt_priv_data {
	struct dev_info dev_info;
	bool erronous;
};

inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt)
{
	return (struct cfpkt_priv_data *) pkt->skb.cb;
}

inline bool is_erronous(struct cfpkt *pkt)
{
	return cfpkt_priv(pkt)->erronous;
}

inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt)
{
	return &pkt->skb;
}

inline struct cfpkt *skb_to_pkt(struct sk_buff *skb)
{
	return (struct cfpkt *) skb;
}


struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt)
{
	struct cfpkt *pkt = skb_to_pkt(nativepkt);
	cfpkt_priv(pkt)->erronous = false;
	return pkt;
}
EXPORT_SYMBOL(cfpkt_fromnative);

void *cfpkt_tonative(struct cfpkt *pkt)
{
	return (void *) pkt;
}
EXPORT_SYMBOL(cfpkt_tonative);

static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx)
{
	struct sk_buff *skb;

	if (likely(in_interrupt()))
		skb = alloc_skb(len + pfx, GFP_ATOMIC);
	else
		skb = alloc_skb(len + pfx, GFP_KERNEL);

	if (unlikely(skb == NULL))
		return NULL;

	skb_reserve(skb, pfx);
	return skb_to_pkt(skb);
}

inline struct cfpkt *cfpkt_create(u16 len)
{
	return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
}
EXPORT_SYMBOL(cfpkt_create);

void cfpkt_destroy(struct cfpkt *pkt)
{
	struct sk_buff *skb = pkt_to_skb(pkt);
	kfree_skb(skb);
}
EXPORT_SYMBOL(cfpkt_destroy);

inline bool cfpkt_more(struct cfpkt *pkt)
{
	struct sk_buff *skb = pkt_to_skb(pkt);
	return skb->len > 0;
}
EXPORT_SYMBOL(cfpkt_more);

int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len)
{
	struct sk_buff *skb = pkt_to_skb(pkt);
	if (skb_headlen(skb) >= len) {
		memcpy(data, skb->data, len);
		return 0;
	}
	return !cfpkt_extr_head(pkt, data, len) &&
	    !cfpkt_add_head(pkt, data, len);
}
EXPORT_SYMBOL(cfpkt_peek_head);

int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len)
{
	struct sk_buff *skb = pkt_to_skb(pkt);
	u8 *from;
	if (unlikely(is_erronous(pkt)))
		return -EPROTO;

	if (unlikely(len > skb->len)) {
		PKT_ERROR(pkt, "read beyond end of packet\n");
		return -EPROTO;
	}

	if (unlikely(len > skb_headlen(skb))) {
		if (unlikely(skb_linearize(skb) != 0)) {
			PKT_ERROR(pkt, "linearize failed\n");
			return -EPROTO;
		}
	}
	from = skb_pull(skb, len);
	from -= len;
	memcpy(data, from, len);
	return 0;
}
EXPORT_SYMBOL(cfpkt_extr_head);

int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len)
{
	struct sk_buff *skb = pkt_to_skb(pkt);
	u8 *data = dta;
	u8 *from;
	if (unlikely(is_erronous(pkt)))
		return -EPROTO;

	if (unlikely(skb_linearize(skb) != 0)) {
		PKT_ERROR(pkt, "linearize failed\n");
		return -EPROTO;
	}
	if (unlikely(skb->data + len > skb_tail_pointer(skb))) {
		PKT_ERROR(pkt, "read beyond end of packet\n");
		return -EPROTO;
	}
	from = skb_tail_pointer(skb) - len;
	skb_trim(skb, skb->len - len);
	memcpy(data, from, len);
	return 0;
}
EXPORT_SYMBOL(cfpkt_extr_trail);

int cfpkt_pad_trail(struct cfpkt *pkt, u16 len)
{
	return cfpkt_add_body(pkt, NULL, len);
}
EXPORT_SYMBOL(cfpkt_pad_trail);

int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len)
{
	struct sk_buff *skb = pkt_to_skb(pkt);
	struct sk_buff *lastskb;
	u8 *to;
	u16 addlen = 0;


	if (unlikely(is_erronous(pkt)))
		return -EPROTO;

	lastskb = skb;

	/* Check whether we need to add space at the tail */
	if (unlikely(skb_tailroom(skb) < len)) {
		if (likely(len < PKT_LEN_WHEN_EXTENDING))
			addlen = PKT_LEN_WHEN_EXTENDING;
		else
			addlen = len;
	}

	/* Check whether we need to change the SKB before writing to the tail */
	if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) {

		/* Make sure data is writable */
		if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) {
			PKT_ERROR(pkt, "cow failed\n");
			return -EPROTO;
		}
		/*
		 * Is the SKB non-linear after skb_cow_data()? If so, we are
		 * going to add data to the last SKB, so we need to adjust
		 * lengths of the top SKB.
		 */
		if (lastskb != skb) {
			pr_warn("Packet is non-linear\n");
			skb->len += len;
			skb->data_len += len;
		}
	}

	/* All set to put the last SKB and optionally write data there. */
	to = skb_put(lastskb, len);
	if (likely(data))
		memcpy(to, data, len);
	return 0;
}
EXPORT_SYMBOL(cfpkt_add_body);

inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data)
{
	return cfpkt_add_body(pkt, &data, 1);
}
EXPORT_SYMBOL(cfpkt_addbdy);

int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len)
{
	struct sk_buff *skb = pkt_to_skb(pkt);
	struct sk_buff *lastskb;
	u8 *to;
	const u8 *data = data2;
	int ret;
	if (unlikely(is_erronous(pkt)))
		return -EPROTO;
	if (unlikely(skb_headroom(skb) < len)) {
		PKT_ERROR(pkt, "no headroom\n");
		return -EPROTO;
	}

	/* Make sure data is writable */
	ret = skb_cow_data(skb, 0, &lastskb);
	if (unlikely(ret < 0)) {
		PKT_ERROR(pkt, "cow failed\n");
		return ret;
	}

	to = skb_push(skb, len);
	memcpy(to, data, len);
	return 0;
}
EXPORT_SYMBOL(cfpkt_add_head);

inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len)
{
	return cfpkt_add_body(pkt, data, len);
}
EXPORT_SYMBOL(cfpkt_add_trail);

inline u16 cfpkt_getlen(struct cfpkt *pkt)
{
	struct sk_buff *skb = pkt_to_skb(pkt);
	return skb->len;
}
EXPORT_SYMBOL(cfpkt_getlen);

inline u16 cfpkt_iterate(struct cfpkt *pkt,
			    u16 (*iter_func)(u16, void *, u16),
			    u16 data)
{
	/*
	 * Don't care about the performance hit of linearizing,
	 * Checksum should not be used on high-speed interfaces anyway.
	 */
	if (unlikely(is_erronous(pkt)))
		return -EPROTO;
	if (unlikely(skb_linearize(&pkt->skb) != 0)) {
		PKT_ERROR(pkt, "linearize failed\n");
		return -EPROTO;
	}
	return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt));
}
EXPORT_SYMBOL(cfpkt_iterate);

int cfpkt_setlen(struct cfpkt *pkt, u16 len)
{
	struct sk_buff *skb = pkt_to_skb(pkt);


	if (unlikely(is_erronous(pkt)))
		return -EPROTO;

	if (likely(len <= skb->len)) {
		if (unlikely(skb->data_len))
			___pskb_trim(skb, len);
		else
			skb_trim(skb, len);

			return cfpkt_getlen(pkt);
	}

	/* Need to expand SKB */
	if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len)))
		PKT_ERROR(pkt, "skb_pad_trail failed\n");

	return cfpkt_getlen(pkt);
}
EXPORT_SYMBOL(cfpkt_setlen);

struct cfpkt *cfpkt_create_uplink(const unsigned char *data, unsigned int len)
{
	struct cfpkt *pkt = cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
	if (!pkt)
		return NULL;
	if (unlikely(data != NULL))
		cfpkt_add_body(pkt, data, len);
	return pkt;
}
EXPORT_SYMBOL(cfpkt_create_uplink);

struct cfpkt *cfpkt_append(struct cfpkt *dstpkt,
			     struct cfpkt *addpkt,
			     u16 expectlen)
{
	struct sk_buff *dst = pkt_to_skb(dstpkt);
	struct sk_buff *add = pkt_to_skb(addpkt);
	u16 addlen = skb_headlen(add);
	u16 neededtailspace;
	struct sk_buff *tmp;
	u16 dstlen;
	u16 createlen;
	if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) {
		return dstpkt;
	}
	if (expectlen > addlen)
		neededtailspace = expectlen;
	else
		neededtailspace = addlen;

	if (dst->tail + neededtailspace > dst->end) {
		/* Create a dumplicate of 'dst' with more tail space */
		struct cfpkt *tmppkt;
		dstlen = skb_headlen(dst);
		createlen = dstlen + neededtailspace;
		tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX);
		if (tmppkt == NULL)
			return NULL;
		tmp = pkt_to_skb(tmppkt);
		skb_set_tail_pointer(tmp, dstlen);
		tmp->len = dstlen;
		memcpy(tmp->data, dst->data, dstlen);
		cfpkt_destroy(dstpkt);
		dst = tmp;
	}
	memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add));
	cfpkt_destroy(addpkt);
	dst->tail += addlen;
	dst->len += addlen;
	return skb_to_pkt(dst);
}
EXPORT_SYMBOL(cfpkt_append);

struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos)
{
	struct sk_buff *skb2;
	struct sk_buff *skb = pkt_to_skb(pkt);
	struct cfpkt *tmppkt;
	u8 *split = skb->data + pos;
	u16 len2nd = skb_tail_pointer(skb) - split;

	if (unlikely(is_erronous(pkt)))
		return NULL;

	if (skb->data + pos > skb_tail_pointer(skb)) {
		PKT_ERROR(pkt, "trying to split beyond end of packet\n");
		return NULL;
	}

	/* Create a new packet for the second part of the data */
	tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
				  PKT_PREFIX);
	if (tmppkt == NULL)
		return NULL;
	skb2 = pkt_to_skb(tmppkt);


	if (skb2 == NULL)
		return NULL;

	/* Reduce the length of the original packet */
	skb_set_tail_pointer(skb, pos);
	skb->len = pos;

	memcpy(skb2->data, split, len2nd);
	skb2->tail += len2nd;
	skb2->len += len2nd;
	return skb_to_pkt(skb2);
}
EXPORT_SYMBOL(cfpkt_split);

char *cfpkt_log_pkt(struct cfpkt *pkt, char *buf, int buflen)
{
	struct sk_buff *skb = pkt_to_skb(pkt);
	char *p = buf;
	int i;

	/*
	 * Sanity check buffer length, it needs to be at least as large as
	 * the header info: ~=50+ bytes
	 */
	if (buflen < 50)
		return NULL;

	snprintf(buf, buflen, "%s: pkt:%p len:%ld(%ld+%ld) {%ld,%ld} data: [",
		is_erronous(pkt) ? "ERRONOUS-SKB" :
		 (skb->data_len != 0 ? "COMPLEX-SKB" : "SKB"),
		 skb,
		 (long) skb->len,
		 (long) (skb_tail_pointer(skb) - skb->data),
		 (long) skb->data_len,
		 (long) (skb->data - skb->head),
		 (long) (skb_tail_pointer(skb) - skb->head));
	p = buf + strlen(buf);

	for (i = 0; i < skb_tail_pointer(skb) - skb->data && i < 300; i++) {
		if (p > buf + buflen - 10) {
			sprintf(p, "...");
			p = buf + strlen(buf);
			break;
		}
		sprintf(p, "%02x,", skb->data[i]);
		p = buf + strlen(buf);
	}
	sprintf(p, "]\n");
	return buf;
}
EXPORT_SYMBOL(cfpkt_log_pkt);

int cfpkt_raw_append(struct cfpkt *pkt, void **buf, unsigned int buflen)
{
	struct sk_buff *skb = pkt_to_skb(pkt);
	struct sk_buff *lastskb;

	caif_assert(buf != NULL);
	if (unlikely(is_erronous(pkt)))
		return -EPROTO;
	/* Make sure SKB is writable */
	if (unlikely(skb_cow_data(skb, 0, &lastskb) < 0)) {
		PKT_ERROR(pkt, "skb_cow_data failed\n");
		return -EPROTO;
	}

	if (unlikely(skb_linearize(skb) != 0)) {
		PKT_ERROR(pkt, "linearize failed\n");
		return -EPROTO;
	}

	if (unlikely(skb_tailroom(skb) < buflen)) {
		PKT_ERROR(pkt, "buffer too short - failed\n");
		return -EPROTO;
	}

	*buf = skb_put(skb, buflen);
	return 1;
}
EXPORT_SYMBOL(cfpkt_raw_append);

int cfpkt_raw_extract(struct cfpkt *pkt, void **buf, unsigned int buflen)
{
	struct sk_buff *skb = pkt_to_skb(pkt);

	caif_assert(buf != NULL);
	if (unlikely(is_erronous(pkt)))
		return -EPROTO;

	if (unlikely(buflen > skb->len)) {
		PKT_ERROR(pkt, "buflen too large - failed\n");
		return -EPROTO;
	}

	if (unlikely(buflen > skb_headlen(skb))) {
		if (unlikely(skb_linearize(skb) != 0)) {
			PKT_ERROR(pkt, "linearize failed\n");
			return -EPROTO;
		}
	}

	*buf = skb->data;
	skb_pull(skb, buflen);

	return 1;
}
EXPORT_SYMBOL(cfpkt_raw_extract);

inline bool cfpkt_erroneous(struct cfpkt *pkt)
{
	return cfpkt_priv(pkt)->erronous;
}
EXPORT_SYMBOL(cfpkt_erroneous);

struct cfpktq *cfpktq_create(void)
{
	struct cfpktq *q = kmalloc(sizeof(struct cfpktq), GFP_ATOMIC);
	if (!q)
		return NULL;
	skb_queue_head_init(&q->head);
	atomic_set(&q->count, 0);
	spin_lock_init(&q->lock);
	return q;
}
EXPORT_SYMBOL(cfpktq_create);

void cfpkt_queue(struct cfpktq *pktq, struct cfpkt *pkt, unsigned short prio)
{
	atomic_inc(&pktq->count);
	spin_lock(&pktq->lock);
	skb_queue_tail(&pktq->head, pkt_to_skb(pkt));
	spin_unlock(&pktq->lock);

}
EXPORT_SYMBOL(cfpkt_queue);

struct cfpkt *cfpkt_qpeek(struct cfpktq *pktq)
{
	struct cfpkt *tmp;
	spin_lock(&pktq->lock);
	tmp = skb_to_pkt(skb_peek(&pktq->head));
	spin_unlock(&pktq->lock);
	return tmp;
}
EXPORT_SYMBOL(cfpkt_qpeek);

struct cfpkt *cfpkt_dequeue(struct cfpktq *pktq)
{
	struct cfpkt *pkt;
	spin_lock(&pktq->lock);
	pkt = skb_to_pkt(skb_dequeue(&pktq->head));
	if (pkt) {
		atomic_dec(&pktq->count);
		caif_assert(atomic_read(&pktq->count) >= 0);
	}
	spin_unlock(&pktq->lock);
	return pkt;
}
EXPORT_SYMBOL(cfpkt_dequeue);

int cfpkt_qcount(struct cfpktq *pktq)
{
	return atomic_read(&pktq->count);
}
EXPORT_SYMBOL(cfpkt_qcount);

struct cfpkt *cfpkt_clone_release(struct cfpkt *pkt)
{
	struct cfpkt *clone;
	clone  = skb_to_pkt(skb_clone(pkt_to_skb(pkt), GFP_ATOMIC));
	/* Free original packet. */
	cfpkt_destroy(pkt);
	if (!clone)
		return NULL;
	return clone;
}
EXPORT_SYMBOL(cfpkt_clone_release);

struct caif_payload_info *cfpkt_info(struct cfpkt *pkt)
{
	return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb;
}
EXPORT_SYMBOL(cfpkt_info);
Commit	Line	Data
15c9ac0c SB	1	/*
	2	* Copyright (C) ST-Ericsson AB 2010
	3	* Author: Sjur Brendeland/sjur.brandeland@stericsson.com
	4	* License terms: GNU General Public License (GPL) version 2
	5	*/
	6
b31fa5ba JP	7	#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
b31fa5ba JP	8
15c9ac0c SB	9	#include <linux/string.h>
	10	#include <linux/skbuff.h>
	11	#include <linux/hardirq.h>
	12	#include <net/caif/cfpkt.h>
	13
24e263ad	14	#define PKT_PREFIX 48
2aa40aef	15	#define PKT_POSTFIX 2
15c9ac0c	16	#define PKT_LEN_WHEN_EXTENDING 128
b31fa5ba JP	17	#define PKT_ERROR(pkt, errmsg) \
	18	do { \
	19	cfpkt_priv(pkt)->erronous = true; \
	20	skb_reset_tail_pointer(&pkt->skb); \
	21	pr_warn(errmsg); \
	22	} while (0)
15c9ac0c SB	23
	24	struct cfpktq {
	25	struct sk_buff_head head;
	26	atomic_t count;
	27	/* Lock protects count updates */
	28	spinlock_t lock;
	29	};
	30
	31	/*
	32	* net/caif/ is generic and does not
	33	* understand SKB, so we do this typecast
	34	*/
	35	struct cfpkt {
	36	struct sk_buff skb;
	37	};
	38
	39	/* Private data inside SKB */
	40	struct cfpkt_priv_data {
	41	struct dev_info dev_info;
	42	bool erronous;
	43	};
	44
	45	inline struct cfpkt_priv_data cfpkt_priv(struct cfpkt pkt)
	46	{
	47	return (struct cfpkt_priv_data *) pkt->skb.cb;
	48	}
	49
	50	inline bool is_erronous(struct cfpkt *pkt)
	51	{
	52	return cfpkt_priv(pkt)->erronous;
	53	}
	54
	55	inline struct sk_buff pkt_to_skb(struct cfpkt pkt)
	56	{
	57	return &pkt->skb;
	58	}
	59
	60	inline struct cfpkt skb_to_pkt(struct sk_buff skb)
	61	{
	62	return (struct cfpkt *) skb;
	63	}
	64
	65
	66	struct cfpkt cfpkt_fromnative(enum caif_direction dir, void nativepkt)
	67	{
	68	struct cfpkt *pkt = skb_to_pkt(nativepkt);
	69	cfpkt_priv(pkt)->erronous = false;
	70	return pkt;
	71	}
	72	EXPORT_SYMBOL(cfpkt_fromnative);
	73
	74	void cfpkt_tonative(struct cfpkt pkt)
	75	{
	76	return (void *) pkt;
	77	}
	78	EXPORT_SYMBOL(cfpkt_tonative);
	79
	80	static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx)
	81	{
	82	struct sk_buff *skb;
	83
	84	if (likely(in_interrupt()))
	85	skb = alloc_skb(len + pfx, GFP_ATOMIC);
	86	else
87	skb = alloc_skb(len + pfx, GFP_KERNEL);
88
89	if (unlikely(skb == NULL))
90	return NULL;
91
92	skb_reserve(skb, pfx);
93	return skb_to_pkt(skb);
94	}
95
96	inline struct cfpkt *cfpkt_create(u16 len)
97	{
98	return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
99	}
100	EXPORT_SYMBOL(cfpkt_create);
101
102	void cfpkt_destroy(struct cfpkt *pkt)
103	{
104	struct sk_buff *skb = pkt_to_skb(pkt);
105	kfree_skb(skb);
106	}
107	EXPORT_SYMBOL(cfpkt_destroy);
108
109	inline bool cfpkt_more(struct cfpkt *pkt)
110	{
111	struct sk_buff *skb = pkt_to_skb(pkt);
112	return skb->len > 0;
113	}
114	EXPORT_SYMBOL(cfpkt_more);
115
116	int cfpkt_peek_head(struct cfpkt pkt, void data, u16 len)
117	{
118	struct sk_buff *skb = pkt_to_skb(pkt);
119	if (skb_headlen(skb) >= len) {
120	memcpy(data, skb->data, len);
121	return 0;
122	}
123	return !cfpkt_extr_head(pkt, data, len) &&
124	!cfpkt_add_head(pkt, data, len);
125	}
126	EXPORT_SYMBOL(cfpkt_peek_head);
127
128	int cfpkt_extr_head(struct cfpkt pkt, void data, u16 len)
129	{
130	struct sk_buff *skb = pkt_to_skb(pkt);
131	u8 *from;
132	if (unlikely(is_erronous(pkt)))
133	return -EPROTO;
134
135	if (unlikely(len > skb->len)) {
b31fa5ba	136	PKT_ERROR(pkt, "read beyond end of packet\n");
15c9ac0c SB	137	return -EPROTO;
	138	}
	139
	140	if (unlikely(len > skb_headlen(skb))) {
	141	if (unlikely(skb_linearize(skb) != 0)) {
b31fa5ba	142	PKT_ERROR(pkt, "linearize failed\n");
15c9ac0c SB	143	return -EPROTO;
	144	}
	145	}
	146	from = skb_pull(skb, len);
	147	from -= len;
	148	memcpy(data, from, len);
	149	return 0;
	150	}
	151	EXPORT_SYMBOL(cfpkt_extr_head);
	152
	153	int cfpkt_extr_trail(struct cfpkt pkt, void dta, u16 len)
	154	{
	155	struct sk_buff *skb = pkt_to_skb(pkt);
	156	u8 *data = dta;
	157	u8 *from;
	158	if (unlikely(is_erronous(pkt)))
	159	return -EPROTO;
	160
	161	if (unlikely(skb_linearize(skb) != 0)) {
b31fa5ba	162	PKT_ERROR(pkt, "linearize failed\n");
15c9ac0c SB	163	return -EPROTO;
	164	}
	165	if (unlikely(skb->data + len > skb_tail_pointer(skb))) {
b31fa5ba	166	PKT_ERROR(pkt, "read beyond end of packet\n");
15c9ac0c SB	167	return -EPROTO;
	168	}
	169	from = skb_tail_pointer(skb) - len;
	170	skb_trim(skb, skb->len - len);
	171	memcpy(data, from, len);
	172	return 0;
	173	}
	174	EXPORT_SYMBOL(cfpkt_extr_trail);
	175
	176	int cfpkt_pad_trail(struct cfpkt *pkt, u16 len)
	177	{
	178	return cfpkt_add_body(pkt, NULL, len);
	179	}
	180	EXPORT_SYMBOL(cfpkt_pad_trail);
	181
	182	int cfpkt_add_body(struct cfpkt pkt, const void data, u16 len)
	183	{
	184	struct sk_buff *skb = pkt_to_skb(pkt);
	185	struct sk_buff *lastskb;
	186	u8 *to;
	187	u16 addlen = 0;
	188
	189
	190	if (unlikely(is_erronous(pkt)))
	191	return -EPROTO;
	192
	193	lastskb = skb;
	194
	195	/* Check whether we need to add space at the tail */
	196	if (unlikely(skb_tailroom(skb) < len)) {
	197	if (likely(len < PKT_LEN_WHEN_EXTENDING))
	198	addlen = PKT_LEN_WHEN_EXTENDING;
	199	else
	200	addlen = len;
	201	}
	202
	203	/* Check whether we need to change the SKB before writing to the tail */
	204	if (unlikely((addlen > 0) \|\| skb_cloned(skb) \|\| skb_shared(skb))) {
	205
	206	/* Make sure data is writable */
	207	if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) {
b31fa5ba	208	PKT_ERROR(pkt, "cow failed\n");
15c9ac0c SB	209	return -EPROTO;
	210	}
	211	/*
	212	* Is the SKB non-linear after skb_cow_data()? If so, we are
	213	* going to add data to the last SKB, so we need to adjust
	214	* lengths of the top SKB.
	215	*/
	216	if (lastskb != skb) {
b31fa5ba	217	pr_warn("Packet is non-linear\n");
15c9ac0c SB	218	skb->len += len;
	219	skb->data_len += len;
	220	}
	221	}
	222
	223	/* All set to put the last SKB and optionally write data there. */
	224	to = skb_put(lastskb, len);
	225	if (likely(data))
	226	memcpy(to, data, len);
	227	return 0;
	228	}
	229	EXPORT_SYMBOL(cfpkt_add_body);
	230
	231	inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data)
	232	{
	233	return cfpkt_add_body(pkt, &data, 1);
	234	}
	235	EXPORT_SYMBOL(cfpkt_addbdy);
	236
	237	int cfpkt_add_head(struct cfpkt pkt, const void data2, u16 len)
	238	{
	239	struct sk_buff *skb = pkt_to_skb(pkt);
	240	struct sk_buff *lastskb;
	241	u8 *to;
	242	const u8 *data = data2;
638e628a	243	int ret;
15c9ac0c SB	244	if (unlikely(is_erronous(pkt)))
	245	return -EPROTO;
	246	if (unlikely(skb_headroom(skb) < len)) {
b31fa5ba	247	PKT_ERROR(pkt, "no headroom\n");
15c9ac0c SB	248	return -EPROTO;
	249	}
	250
	251	/* Make sure data is writable */
638e628a SB	252	ret = skb_cow_data(skb, 0, &lastskb);
638e628a SB	253	if (unlikely(ret < 0)) {
b31fa5ba	254	PKT_ERROR(pkt, "cow failed\n");
638e628a	255	return ret;
15c9ac0c SB	256	}
	257
	258	to = skb_push(skb, len);
	259	memcpy(to, data, len);
	260	return 0;
	261	}
	262	EXPORT_SYMBOL(cfpkt_add_head);
	263
	264	inline int cfpkt_add_trail(struct cfpkt pkt, const void data, u16 len)
	265	{
	266	return cfpkt_add_body(pkt, data, len);
	267	}
	268	EXPORT_SYMBOL(cfpkt_add_trail);
	269
	270	inline u16 cfpkt_getlen(struct cfpkt *pkt)
	271	{
	272	struct sk_buff *skb = pkt_to_skb(pkt);
	273	return skb->len;
	274	}
	275	EXPORT_SYMBOL(cfpkt_getlen);
	276
	277	inline u16 cfpkt_iterate(struct cfpkt *pkt,
	278	u16 (iter_func)(u16, void , u16),
	279	u16 data)
	280	{
	281	/*
	282	* Don't care about the performance hit of linearizing,
	283	* Checksum should not be used on high-speed interfaces anyway.
	284	*/
	285	if (unlikely(is_erronous(pkt)))
	286	return -EPROTO;
	287	if (unlikely(skb_linearize(&pkt->skb) != 0)) {
b31fa5ba	288	PKT_ERROR(pkt, "linearize failed\n");
15c9ac0c SB	289	return -EPROTO;
	290	}
	291	return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt));
	292	}
	293	EXPORT_SYMBOL(cfpkt_iterate);
	294
	295	int cfpkt_setlen(struct cfpkt *pkt, u16 len)
	296	{
	297	struct sk_buff *skb = pkt_to_skb(pkt);
	298
	299
	300	if (unlikely(is_erronous(pkt)))
	301	return -EPROTO;
	302
	303	if (likely(len <= skb->len)) {
	304	if (unlikely(skb->data_len))
	305	___pskb_trim(skb, len);
	306	else
	307	skb_trim(skb, len);
	308
	309	return cfpkt_getlen(pkt);
	310	}
	311
	312	/* Need to expand SKB */
	313	if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len)))
b31fa5ba	314	PKT_ERROR(pkt, "skb_pad_trail failed\n");
15c9ac0c SB	315
	316	return cfpkt_getlen(pkt);
	317	}
	318	EXPORT_SYMBOL(cfpkt_setlen);
	319
	320	struct cfpkt cfpkt_create_uplink(const unsigned char data, unsigned int len)
	321	{
	322	struct cfpkt *pkt = cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
638e628a SB	323	if (!pkt)
638e628a SB	324	return NULL;
15c9ac0c SB	325	if (unlikely(data != NULL))
	326	cfpkt_add_body(pkt, data, len);
	327	return pkt;
	328	}
	329	EXPORT_SYMBOL(cfpkt_create_uplink);
	330
	331	struct cfpkt cfpkt_append(struct cfpkt dstpkt,
	332	struct cfpkt *addpkt,
	333	u16 expectlen)
	334	{
	335	struct sk_buff *dst = pkt_to_skb(dstpkt);
	336	struct sk_buff *add = pkt_to_skb(addpkt);
	337	u16 addlen = skb_headlen(add);
	338	u16 neededtailspace;
	339	struct sk_buff *tmp;
	340	u16 dstlen;
	341	u16 createlen;
	342	if (unlikely(is_erronous(dstpkt) \|\| is_erronous(addpkt))) {
15c9ac0c SB	343	return dstpkt;
	344	}
	345	if (expectlen > addlen)
	346	neededtailspace = expectlen;
	347	else
	348	neededtailspace = addlen;
	349
	350	if (dst->tail + neededtailspace > dst->end) {
	351	/* Create a dumplicate of 'dst' with more tail space */
638e628a	352	struct cfpkt *tmppkt;
15c9ac0c SB	353	dstlen = skb_headlen(dst);
15c9ac0c SB	354	createlen = dstlen + neededtailspace;
638e628a SB	355	tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX);
638e628a SB	356	if (tmppkt == NULL)
15c9ac0c	357	return NULL;
638e628a	358	tmp = pkt_to_skb(tmppkt);
15c9ac0c SB	359	skb_set_tail_pointer(tmp, dstlen);
	360	tmp->len = dstlen;
	361	memcpy(tmp->data, dst->data, dstlen);
	362	cfpkt_destroy(dstpkt);
	363	dst = tmp;
	364	}
	365	memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add));
	366	cfpkt_destroy(addpkt);
	367	dst->tail += addlen;
	368	dst->len += addlen;
	369	return skb_to_pkt(dst);
	370	}
	371	EXPORT_SYMBOL(cfpkt_append);
	372
	373	struct cfpkt cfpkt_split(struct cfpkt pkt, u16 pos)
	374	{
	375	struct sk_buff *skb2;
	376	struct sk_buff *skb = pkt_to_skb(pkt);
638e628a	377	struct cfpkt *tmppkt;
15c9ac0c SB	378	u8 *split = skb->data + pos;
	379	u16 len2nd = skb_tail_pointer(skb) - split;
	380
	381	if (unlikely(is_erronous(pkt)))
	382	return NULL;
	383
	384	if (skb->data + pos > skb_tail_pointer(skb)) {
b31fa5ba	385	PKT_ERROR(pkt, "trying to split beyond end of packet\n");
15c9ac0c SB	386	return NULL;
	387	}
	388
	389	/* Create a new packet for the second part of the data */
638e628a SB	390	tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
	391	PKT_PREFIX);
	392	if (tmppkt == NULL)
	393	return NULL;
	394	skb2 = pkt_to_skb(tmppkt);
	395
15c9ac0c SB	396
	397	if (skb2 == NULL)
	398	return NULL;
	399
	400	/* Reduce the length of the original packet */
	401	skb_set_tail_pointer(skb, pos);
	402	skb->len = pos;
	403
	404	memcpy(skb2->data, split, len2nd);
	405	skb2->tail += len2nd;
	406	skb2->len += len2nd;
	407	return skb_to_pkt(skb2);
	408	}
	409	EXPORT_SYMBOL(cfpkt_split);
	410
	411	char cfpkt_log_pkt(struct cfpkt pkt, char *buf, int buflen)
	412	{
	413	struct sk_buff *skb = pkt_to_skb(pkt);
	414	char *p = buf;
	415	int i;
	416
	417	/*
	418	* Sanity check buffer length, it needs to be at least as large as
	419	* the header info: ~=50+ bytes
	420	*/
	421	if (buflen < 50)
	422	return NULL;
	423
	424	snprintf(buf, buflen, "%s: pkt:%p len:%ld(%ld+%ld) {%ld,%ld} data: [",
	425	is_erronous(pkt) ? "ERRONOUS-SKB" :
	426	(skb->data_len != 0 ? "COMPLEX-SKB" : "SKB"),
	427	skb,
	428	(long) skb->len,
	429	(long) (skb_tail_pointer(skb) - skb->data),
	430	(long) skb->data_len,
	431	(long) (skb->data - skb->head),
	432	(long) (skb_tail_pointer(skb) - skb->head));
	433	p = buf + strlen(buf);
	434
	435	for (i = 0; i < skb_tail_pointer(skb) - skb->data && i < 300; i++) {
	436	if (p > buf + buflen - 10) {
	437	sprintf(p, "...");
	438	p = buf + strlen(buf);
	439	break;
	440	}
	441	sprintf(p, "%02x,", skb->data[i]);
	442	p = buf + strlen(buf);
	443	}
	444	sprintf(p, "]\n");
	445	return buf;
	446	}
	447	EXPORT_SYMBOL(cfpkt_log_pkt);
	448
	449	int cfpkt_raw_append(struct cfpkt pkt, void *buf, unsigned int buflen)
	450	{
	451	struct sk_buff *skb = pkt_to_skb(pkt);
	452	struct sk_buff *lastskb;
	453
	454	caif_assert(buf != NULL);
	455	if (unlikely(is_erronous(pkt)))
	456	return -EPROTO;
	457	/* Make sure SKB is writable */
	458	if (unlikely(skb_cow_data(skb, 0, &lastskb) < 0)) {
b31fa5ba	459	PKT_ERROR(pkt, "skb_cow_data failed\n");
15c9ac0c SB	460	return -EPROTO;
	461	}
	462
	463	if (unlikely(skb_linearize(skb) != 0)) {
b31fa5ba	464	PKT_ERROR(pkt, "linearize failed\n");
15c9ac0c SB	465	return -EPROTO;
	466	}
	467
	468	if (unlikely(skb_tailroom(skb) < buflen)) {
b31fa5ba	469	PKT_ERROR(pkt, "buffer too short - failed\n");
15c9ac0c SB	470	return -EPROTO;
	471	}
	472
	473	*buf = skb_put(skb, buflen);
	474	return 1;
	475	}
	476	EXPORT_SYMBOL(cfpkt_raw_append);
	477
	478	int cfpkt_raw_extract(struct cfpkt pkt, void *buf, unsigned int buflen)
	479	{
	480	struct sk_buff *skb = pkt_to_skb(pkt);
	481
	482	caif_assert(buf != NULL);
	483	if (unlikely(is_erronous(pkt)))
	484	return -EPROTO;
	485
	486	if (unlikely(buflen > skb->len)) {
b31fa5ba	487	PKT_ERROR(pkt, "buflen too large - failed\n");
15c9ac0c SB	488	return -EPROTO;
	489	}
	490
	491	if (unlikely(buflen > skb_headlen(skb))) {
	492	if (unlikely(skb_linearize(skb) != 0)) {
b31fa5ba	493	PKT_ERROR(pkt, "linearize failed\n");
15c9ac0c SB	494	return -EPROTO;
	495	}
	496	}
	497
	498	*buf = skb->data;
	499	skb_pull(skb, buflen);
	500
	501	return 1;
	502	}
	503	EXPORT_SYMBOL(cfpkt_raw_extract);
	504
	505	inline bool cfpkt_erroneous(struct cfpkt *pkt)
	506	{
	507	return cfpkt_priv(pkt)->erronous;
	508	}
	509	EXPORT_SYMBOL(cfpkt_erroneous);
	510
	511	struct cfpktq *cfpktq_create(void)
	512	{
	513	struct cfpktq *q = kmalloc(sizeof(struct cfpktq), GFP_ATOMIC);
	514	if (!q)
	515	return NULL;
	516	skb_queue_head_init(&q->head);
	517	atomic_set(&q->count, 0);
	518	spin_lock_init(&q->lock);
	519	return q;
	520	}
	521	EXPORT_SYMBOL(cfpktq_create);
	522
	523	void cfpkt_queue(struct cfpktq pktq, struct cfpkt pkt, unsigned short prio)
	524	{
	525	atomic_inc(&pktq->count);
	526	spin_lock(&pktq->lock);
	527	skb_queue_tail(&pktq->head, pkt_to_skb(pkt));
	528	spin_unlock(&pktq->lock);
	529
	530	}
	531	EXPORT_SYMBOL(cfpkt_queue);
	532
	533	struct cfpkt cfpkt_qpeek(struct cfpktq pktq)
	534	{
	535	struct cfpkt *tmp;
	536	spin_lock(&pktq->lock);
	537	tmp = skb_to_pkt(skb_peek(&pktq->head));
	538	spin_unlock(&pktq->lock);
	539	return tmp;
	540	}
	541	EXPORT_SYMBOL(cfpkt_qpeek);
	542
	543	struct cfpkt cfpkt_dequeue(struct cfpktq pktq)
	544	{
	545	struct cfpkt *pkt;
	546	spin_lock(&pktq->lock);
	547	pkt = skb_to_pkt(skb_dequeue(&pktq->head));
	548	if (pkt) {
	549	atomic_dec(&pktq->count);
	550	caif_assert(atomic_read(&pktq->count) >= 0);
	551	}
	552	spin_unlock(&pktq->lock);
	553	return pkt;
	554	}
	555	EXPORT_SYMBOL(cfpkt_dequeue);
	556
	557	int cfpkt_qcount(struct cfpktq *pktq)
558	{
559	return atomic_read(&pktq->count);
560	}
561	EXPORT_SYMBOL(cfpkt_qcount);
562
563	struct cfpkt cfpkt_clone_release(struct cfpkt pkt)
564	{
565	struct cfpkt *clone;
566	clone = skb_to_pkt(skb_clone(pkt_to_skb(pkt), GFP_ATOMIC));
567	/* Free original packet. */
568	cfpkt_destroy(pkt);
569	if (!clone)
570	return NULL;
571	return clone;
572	}
573	EXPORT_SYMBOL(cfpkt_clone_release);
574
575	struct caif_payload_info cfpkt_info(struct cfpkt pkt)
576	{
577	return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb;
578	}
579	EXPORT_SYMBOL(cfpkt_info);