strparser.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Stream Parser
  4 *
  5 * Copyright (c) 2016 Tom Herbert <tom@herbertland.com>
  6 */
  7
  8#ifndef __NET_STRPARSER_H_
  9#define __NET_STRPARSER_H_
 10
 11#include <linux/skbuff.h>
 12#include <net/sock.h>
 13
 14#define STRP_STATS_ADD(stat, count) ((stat) += (count))
 15#define STRP_STATS_INCR(stat) ((stat)++)
 16
 17struct strp_stats {
 18	unsigned long long msgs;
 19	unsigned long long bytes;
 20	unsigned int mem_fail;
 21	unsigned int need_more_hdr;
 22	unsigned int msg_too_big;
 23	unsigned int msg_timeouts;
 24	unsigned int bad_hdr_len;
 25};
 26
 27struct strp_aggr_stats {
 28	unsigned long long msgs;
 29	unsigned long long bytes;
 30	unsigned int mem_fail;
 31	unsigned int need_more_hdr;
 32	unsigned int msg_too_big;
 33	unsigned int msg_timeouts;
 34	unsigned int bad_hdr_len;
 35	unsigned int aborts;
 36	unsigned int interrupted;
 37	unsigned int unrecov_intr;
 38};
 39
 40struct strparser;
 41
 42/* Callbacks are called with lock held for the attached socket */
 43struct strp_callbacks {
 44	int (*parse_msg)(struct strparser *strp, struct sk_buff *skb);
 45	void (*rcv_msg)(struct strparser *strp, struct sk_buff *skb);
 46	int (*read_sock)(struct strparser *strp, read_descriptor_t *desc,
 47			 sk_read_actor_t recv_actor);
 48	int (*read_sock_done)(struct strparser *strp, int err);
 49	void (*abort_parser)(struct strparser *strp, int err);
 50	void (*lock)(struct strparser *strp);
 51	void (*unlock)(struct strparser *strp);
 52};
 53
 54struct strp_msg {
 55	int full_len;
 56	int offset;
 57};
 58
 59struct _strp_msg {
 60	/* Internal cb structure. struct strp_msg must be first for passing
 61	 * to upper layer.
 62	 */
 63	struct strp_msg strp;
 64	int accum_len;
 65};
 66
 67struct sk_skb_cb {
 68#define SK_SKB_CB_PRIV_LEN 20
 69	unsigned char data[SK_SKB_CB_PRIV_LEN];
 70	/* align strp on cache line boundary within skb->cb[] */
 71	unsigned char pad[4];
 72	struct _strp_msg strp;
 73
 74	/* strp users' data follows */
 75	struct tls_msg {
 76		u8 control;
 77	} tls;
 78	/* temp_reg is a temporary register used for bpf_convert_data_end_access
 79	 * when dst_reg == src_reg.
 80	 */
 81	u64 temp_reg;
 82};
 83
 84static inline struct strp_msg *strp_msg(struct sk_buff *skb)
 85{
 86	return (struct strp_msg *)((void *)skb->cb +
 87		offsetof(struct sk_skb_cb, strp));
 88}
 89
 90/* Structure for an attached lower socket */
 91struct strparser {
 92	struct sock *sk;
 93
 94	u32 stopped : 1;
 95	u32 paused : 1;
 96	u32 aborted : 1;
 97	u32 interrupted : 1;
 98	u32 unrecov_intr : 1;
 99
100	struct sk_buff **skb_nextp;
101	struct sk_buff *skb_head;
102	unsigned int need_bytes;
103	struct delayed_work msg_timer_work;
104	struct work_struct work;
105	struct strp_stats stats;
106	struct strp_callbacks cb;
107};
108
109/* Must be called with lock held for attached socket */
110static inline void strp_pause(struct strparser *strp)
111{
112	strp->paused = 1;
113}
114
115/* May be called without holding lock for attached socket */
116void strp_unpause(struct strparser *strp);
117
118static inline void save_strp_stats(struct strparser *strp,
119				   struct strp_aggr_stats *agg_stats)
120{
121	/* Save psock statistics in the mux when psock is being unattached. */
122
123#define SAVE_PSOCK_STATS(_stat) (agg_stats->_stat +=		\
124				 strp->stats._stat)
125	SAVE_PSOCK_STATS(msgs);
126	SAVE_PSOCK_STATS(bytes);
127	SAVE_PSOCK_STATS(mem_fail);
128	SAVE_PSOCK_STATS(need_more_hdr);
129	SAVE_PSOCK_STATS(msg_too_big);
130	SAVE_PSOCK_STATS(msg_timeouts);
131	SAVE_PSOCK_STATS(bad_hdr_len);
132#undef SAVE_PSOCK_STATS
133
134	if (strp->aborted)
135		agg_stats->aborts++;
136	if (strp->interrupted)
137		agg_stats->interrupted++;
138	if (strp->unrecov_intr)
139		agg_stats->unrecov_intr++;
140}
141
142static inline void aggregate_strp_stats(struct strp_aggr_stats *stats,
143					struct strp_aggr_stats *agg_stats)
144{
145#define SAVE_PSOCK_STATS(_stat) (agg_stats->_stat += stats->_stat)
146	SAVE_PSOCK_STATS(msgs);
147	SAVE_PSOCK_STATS(bytes);
148	SAVE_PSOCK_STATS(mem_fail);
149	SAVE_PSOCK_STATS(need_more_hdr);
150	SAVE_PSOCK_STATS(msg_too_big);
151	SAVE_PSOCK_STATS(msg_timeouts);
152	SAVE_PSOCK_STATS(bad_hdr_len);
153	SAVE_PSOCK_STATS(aborts);
154	SAVE_PSOCK_STATS(interrupted);
155	SAVE_PSOCK_STATS(unrecov_intr);
156#undef SAVE_PSOCK_STATS
157
158}
159
160void strp_done(struct strparser *strp);
161void strp_stop(struct strparser *strp);
162void strp_check_rcv(struct strparser *strp);
163int strp_init(struct strparser *strp, struct sock *sk,
164	      const struct strp_callbacks *cb);
165void strp_data_ready(struct strparser *strp);
166int strp_process(struct strparser *strp, struct sk_buff *orig_skb,
167		 unsigned int orig_offset, size_t orig_len,
168		 size_t max_msg_size, long timeo);
169
170#endif /* __NET_STRPARSER_H_ */