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 rx_msgs;
 22	unsigned long long rx_bytes;
 23	unsigned int rx_mem_fail;
 24	unsigned int rx_need_more_hdr;
 25	unsigned int rx_msg_too_big;
 26	unsigned int rx_msg_timeouts;
 27	unsigned int rx_bad_hdr_len;
 28};
 29
 30struct strp_aggr_stats {
 31	unsigned long long rx_msgs;
 32	unsigned long long rx_bytes;
 33	unsigned int rx_mem_fail;
 34	unsigned int rx_need_more_hdr;
 35	unsigned int rx_msg_too_big;
 36	unsigned int rx_msg_timeouts;
 37	unsigned int rx_bad_hdr_len;
 38	unsigned int rx_aborts;
 39	unsigned int rx_interrupted;
 40	unsigned int rx_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};
 52
 53struct strp_rx_msg {
 54	int full_len;
 55	int offset;
 56};
 57
 58static inline struct strp_rx_msg *strp_rx_msg(struct sk_buff *skb)
 59{
 60	return (struct strp_rx_msg *)((void *)skb->cb +
 61		offsetof(struct qdisc_skb_cb, data));
 62}
 63
 64/* Structure for an attached lower socket */
 65struct strparser {
 66	struct sock *sk;
 67
 68	u32 rx_stopped : 1;
 69	u32 rx_paused : 1;
 70	u32 rx_aborted : 1;
 71	u32 rx_interrupted : 1;
 72	u32 rx_unrecov_intr : 1;
 73
 74	struct sk_buff **rx_skb_nextp;
 75	struct timer_list rx_msg_timer;
 76	struct sk_buff *rx_skb_head;
 77	unsigned int rx_need_bytes;
 78	struct delayed_work rx_delayed_work;
 79	struct work_struct rx_work;
 80	struct strp_stats stats;
 81	struct strp_callbacks cb;
 82};
 83
 84/* Must be called with lock held for attached socket */
 85static inline void strp_pause(struct strparser *strp)
 86{
 87	strp->rx_paused = 1;
 88}
 89
 90/* May be called without holding lock for attached socket */
 91void strp_unpause(struct strparser *strp);
 92
 93static inline void save_strp_stats(struct strparser *strp,
 94				   struct strp_aggr_stats *agg_stats)
 95{
 96	/* Save psock statistics in the mux when psock is being unattached. */
 97
 98#define SAVE_PSOCK_STATS(_stat) (agg_stats->_stat +=		\
 99				 strp->stats._stat)
100	SAVE_PSOCK_STATS(rx_msgs);
101	SAVE_PSOCK_STATS(rx_bytes);
102	SAVE_PSOCK_STATS(rx_mem_fail);
103	SAVE_PSOCK_STATS(rx_need_more_hdr);
104	SAVE_PSOCK_STATS(rx_msg_too_big);
105	SAVE_PSOCK_STATS(rx_msg_timeouts);
106	SAVE_PSOCK_STATS(rx_bad_hdr_len);
107#undef SAVE_PSOCK_STATS
108
109	if (strp->rx_aborted)
110		agg_stats->rx_aborts++;
111	if (strp->rx_interrupted)
112		agg_stats->rx_interrupted++;
113	if (strp->rx_unrecov_intr)
114		agg_stats->rx_unrecov_intr++;
115}
116
117static inline void aggregate_strp_stats(struct strp_aggr_stats *stats,
118					struct strp_aggr_stats *agg_stats)
119{
120#define SAVE_PSOCK_STATS(_stat) (agg_stats->_stat += stats->_stat)
121	SAVE_PSOCK_STATS(rx_msgs);
122	SAVE_PSOCK_STATS(rx_bytes);
123	SAVE_PSOCK_STATS(rx_mem_fail);
124	SAVE_PSOCK_STATS(rx_need_more_hdr);
125	SAVE_PSOCK_STATS(rx_msg_too_big);
126	SAVE_PSOCK_STATS(rx_msg_timeouts);
127	SAVE_PSOCK_STATS(rx_bad_hdr_len);
128	SAVE_PSOCK_STATS(rx_aborts);
129	SAVE_PSOCK_STATS(rx_interrupted);
130	SAVE_PSOCK_STATS(rx_unrecov_intr);
131#undef SAVE_PSOCK_STATS
132
133}
134
135void strp_done(struct strparser *strp);
136void strp_stop(struct strparser *strp);
137void strp_check_rcv(struct strparser *strp);
138int strp_init(struct strparser *strp, struct sock *csk,
139	      struct strp_callbacks *cb);
140void strp_data_ready(struct strparser *strp);
141
142#endif /* __NET_STRPARSER_H_ */