xref: /linux/include/net/strparser.h (revision d8674294aefef02266c4d47ad10131f1bffbe534)
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 
17 struct 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 
27 struct 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 interrupted;
36 	unsigned int unrecov_intr;
37 };
38 
39 struct strparser;
40 
41 /* Callbacks are called with lock held for the attached socket */
42 struct strp_callbacks {
43 	int (*parse_msg)(struct strparser *strp, struct sk_buff *skb);
44 	void (*rcv_msg)(struct strparser *strp, struct sk_buff *skb);
45 	int (*read_sock)(struct strparser *strp, read_descriptor_t *desc,
46 			 sk_read_actor_t recv_actor);
47 	int (*read_sock_done)(struct strparser *strp, int err);
48 };
49 
50 struct strp_msg {
51 	int full_len;
52 	int offset;
53 };
54 
55 struct _strp_msg {
56 	/* Internal cb structure. struct strp_msg must be first for passing
57 	 * to upper layer.
58 	 */
59 	struct strp_msg strp;
60 	int accum_len;
61 };
62 
63 struct sk_skb_cb {
64 #define SK_SKB_CB_PRIV_LEN 20
65 	unsigned char data[SK_SKB_CB_PRIV_LEN];
66 	/* align strp on cache line boundary within skb->cb[] */
67 	unsigned char pad[4];
68 	struct _strp_msg strp;
69 
70 	/* strp users' data follows */
71 	struct tls_msg {
72 		u8 control;
73 	} tls;
74 	/* temp_reg is a temporary register used for bpf_convert_data_end_access
75 	 * when dst_reg == src_reg.
76 	 */
77 	u64 temp_reg;
78 };
79 
80 static inline struct strp_msg *strp_msg(struct sk_buff *skb)
81 {
82 	return (struct strp_msg *)((void *)skb->cb +
83 		offsetof(struct sk_skb_cb, strp));
84 }
85 
86 /* Structure for an attached lower socket */
87 struct strparser {
88 	struct sock *sk;
89 
90 	u8 stopped;
91 	u8 paused;
92 	u8 interrupted;
93 	u8 unrecov_intr;
94 
95 	struct sk_buff **skb_nextp;
96 	struct sk_buff *skb_head;
97 	unsigned int need_bytes;
98 	struct delayed_work msg_timer_work;
99 	struct work_struct work;
100 	struct strp_stats stats;
101 	struct strp_callbacks cb;
102 };
103 
104 /* Must be called with lock held for attached socket */
105 static inline void strp_pause(struct strparser *strp)
106 {
107 	strp->paused = 1;
108 }
109 
110 /* May be called without holding lock for attached socket */
111 void strp_unpause(struct strparser *strp);
112 
113 static inline void save_strp_stats(struct strparser *strp,
114 				   struct strp_aggr_stats *agg_stats)
115 {
116 	/* Save psock statistics in the mux when psock is being unattached. */
117 
118 #define SAVE_PSOCK_STATS(_stat) (agg_stats->_stat +=		\
119 				 strp->stats._stat)
120 	SAVE_PSOCK_STATS(msgs);
121 	SAVE_PSOCK_STATS(bytes);
122 	SAVE_PSOCK_STATS(mem_fail);
123 	SAVE_PSOCK_STATS(need_more_hdr);
124 	SAVE_PSOCK_STATS(msg_too_big);
125 	SAVE_PSOCK_STATS(msg_timeouts);
126 	SAVE_PSOCK_STATS(bad_hdr_len);
127 #undef SAVE_PSOCK_STATS
128 
129 	if (strp->interrupted)
130 		agg_stats->interrupted++;
131 	if (strp->unrecov_intr)
132 		agg_stats->unrecov_intr++;
133 }
134 
135 static inline void aggregate_strp_stats(struct strp_aggr_stats *stats,
136 					struct strp_aggr_stats *agg_stats)
137 {
138 #define SAVE_PSOCK_STATS(_stat) (agg_stats->_stat += stats->_stat)
139 	SAVE_PSOCK_STATS(msgs);
140 	SAVE_PSOCK_STATS(bytes);
141 	SAVE_PSOCK_STATS(mem_fail);
142 	SAVE_PSOCK_STATS(need_more_hdr);
143 	SAVE_PSOCK_STATS(msg_too_big);
144 	SAVE_PSOCK_STATS(msg_timeouts);
145 	SAVE_PSOCK_STATS(bad_hdr_len);
146 	SAVE_PSOCK_STATS(interrupted);
147 	SAVE_PSOCK_STATS(unrecov_intr);
148 #undef SAVE_PSOCK_STATS
149 
150 }
151 
152 void strp_done(struct strparser *strp);
153 void strp_stop(struct strparser *strp);
154 void strp_check_rcv(struct strparser *strp);
155 int strp_init(struct strparser *strp, struct sock *sk,
156 	      const struct strp_callbacks *cb);
157 void strp_data_ready(struct strparser *strp);
158 
159 #endif /* __NET_STRPARSER_H_ */
160