1/*
  2 * Stream Parser
  3 *
  4 * Copyright (c) 2016 Tom Herbert <tom@herbertland.com>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2
  8 * as published by the Free Software Foundation.
  9 */
 10
 11#ifndef __NET_STRPARSER_H_
 12#define __NET_STRPARSER_H_
 13
 14#include <linux/skbuff.h>
 15#include <net/sock.h>
 16
 17#define STRP_STATS_ADD(stat, count) ((stat) += (count))
 18#define STRP_STATS_INCR(stat) ((stat)++)
 19
 20struct strp_stats {
 21	unsigned long long msgs;
 22	unsigned long long bytes;
 23	unsigned int mem_fail;
 24	unsigned int need_more_hdr;
 25	unsigned int msg_too_big;
 26	unsigned int msg_timeouts;
 27	unsigned int bad_hdr_len;
 28};
 29
 30struct strp_aggr_stats {
 31	unsigned long long msgs;
 32	unsigned long long bytes;
 33	unsigned int mem_fail;
 34	unsigned int need_more_hdr;
 35	unsigned int msg_too_big;
 36	unsigned int msg_timeouts;
 37	unsigned int bad_hdr_len;
 38	unsigned int aborts;
 39	unsigned int interrupted;
 40	unsigned int unrecov_intr;
 41};
 42
 43struct strparser;
 44
 45/* Callbacks are called with lock held for the attached socket */
 46struct strp_callbacks {
 47	int (*parse_msg)(struct strparser *strp, struct sk_buff *skb);
 48	void (*rcv_msg)(struct strparser *strp, struct sk_buff *skb);
 49	int (*read_sock_done)(struct strparser *strp, int err);
 50	void (*abort_parser)(struct strparser *strp, int err);
 51	void (*lock)(struct strparser *strp);
 52	void (*unlock)(struct strparser *strp);
 53};
 54
 55struct strp_msg {
 56	int full_len;
 57	int offset;
 58};
 59
 60static inline struct strp_msg *strp_msg(struct sk_buff *skb)
 61{
 62	return (struct strp_msg *)((void *)skb->cb +
 63		offsetof(struct qdisc_skb_cb, data));
 64}
 65
 66/* Structure for an attached lower socket */
 67struct strparser {
 68	struct sock *sk;
 69
 70	u32 stopped : 1;
 71	u32 paused : 1;
 72	u32 aborted : 1;
 73	u32 interrupted : 1;
 74	u32 unrecov_intr : 1;
 75
 76	struct sk_buff **skb_nextp;
 77	struct sk_buff *skb_head;
 78	unsigned int need_bytes;
 79	struct delayed_work msg_timer_work;
 80	struct work_struct work;
 81	struct strp_stats stats;
 82	struct strp_callbacks cb;
 83};
 84
 85/* Must be called with lock held for attached socket */
 86static inline void strp_pause(struct strparser *strp)
 87{
 88	strp->paused = 1;
 89}
 90
 91/* May be called without holding lock for attached socket */
 92void strp_unpause(struct strparser *strp);
 93
 94static inline void save_strp_stats(struct strparser *strp,
 95				   struct strp_aggr_stats *agg_stats)
 96{
 97	/* Save psock statistics in the mux when psock is being unattached. */
 98
 99#define SAVE_PSOCK_STATS(_stat) (agg_stats->_stat +=		\
100				 strp->stats._stat)
101	SAVE_PSOCK_STATS(msgs);
102	SAVE_PSOCK_STATS(bytes);
103	SAVE_PSOCK_STATS(mem_fail);
104	SAVE_PSOCK_STATS(need_more_hdr);
105	SAVE_PSOCK_STATS(msg_too_big);
106	SAVE_PSOCK_STATS(msg_timeouts);
107	SAVE_PSOCK_STATS(bad_hdr_len);
108#undef SAVE_PSOCK_STATS
109
110	if (strp->aborted)
111		agg_stats->aborts++;
112	if (strp->interrupted)
113		agg_stats->interrupted++;
114	if (strp->unrecov_intr)
115		agg_stats->unrecov_intr++;
116}
117
118static inline void aggregate_strp_stats(struct strp_aggr_stats *stats,
119					struct strp_aggr_stats *agg_stats)
120{
121#define SAVE_PSOCK_STATS(_stat) (agg_stats->_stat += stats->_stat)
122	SAVE_PSOCK_STATS(msgs);
123	SAVE_PSOCK_STATS(bytes);
124	SAVE_PSOCK_STATS(mem_fail);
125	SAVE_PSOCK_STATS(need_more_hdr);
126	SAVE_PSOCK_STATS(msg_too_big);
127	SAVE_PSOCK_STATS(msg_timeouts);
128	SAVE_PSOCK_STATS(bad_hdr_len);
129	SAVE_PSOCK_STATS(aborts);
130	SAVE_PSOCK_STATS(interrupted);
131	SAVE_PSOCK_STATS(unrecov_intr);
132#undef SAVE_PSOCK_STATS
133
134}
135
136void strp_done(struct strparser *strp);
137void strp_stop(struct strparser *strp);
138void strp_check_rcv(struct strparser *strp);
139int strp_init(struct strparser *strp, struct sock *sk,
140	      const struct strp_callbacks *cb);
141void strp_data_ready(struct strparser *strp);
142int strp_process(struct strparser *strp, struct sk_buff *orig_skb,
143		 unsigned int orig_offset, size_t orig_len,
144		 size_t max_msg_size, long timeo);
145
146#endif /* __NET_STRPARSER_H_ */