public inbox for passt-dev@passt.top
 help / color / mirror / code / Atom feed
blob d6650fc067edacde90ceb2e00ea3a33fdef3bcc8 3505 bytes (raw)

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
 
/* SPDX-License-Identifier: GPL-2.0-or-later
 * Copyright Red Hat
 * Author: David Gibson <david@gibson.dropbear.id.au>
 *
 * Tracking for logical "flows" of packets.
 */

#include <stdint.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

#include "util.h"
#include "passt.h"
#include "siphash.h"
#include "inany.h"
#include "flow.h"
#include "flow_table.h"

const char *flow_type_str[] = {
	[FLOW_TYPE_NONE]	= "<none>",
	[FLOW_TCP]		= "TCP connection",
	[FLOW_TCP_SPLICE]	= "TCP connection (spliced)",
};
static_assert(ARRAY_SIZE(flow_type_str) == FLOW_NUM_TYPES,
	      "flow_type_str[] doesn't match enum flow_type");

/* Global Flow Table */
unsigned flow_count;
union flow flowtab[FLOW_MAX];

/* Last time the flow timers ran */
static struct timespec flow_timer_run;

/** flow_log_ - Log flow-related message
 * @f:		flow the message is related to
 * @pri:	Log priority
 * @fmt:	Format string
 * @...:	printf-arguments
 */
void flow_log_(const struct flow_common *f, int pri, const char *fmt, ...)
{
	char msg[BUFSIZ];
	va_list args;

	va_start(args, fmt);
	(void)vsnprintf(msg, sizeof(msg), fmt, args);
	va_end(args);

	logmsg(pri, "Flow %u (%s): %s", flow_idx(f), FLOW_TYPE(f), msg);
}

/**
 * flow_alloc() - Allocate a new flow
 *
 * Return: pointer to an unused flow entry, or NULL if the table is full
 */
union flow *flow_alloc(void)
{
	if (flow_count >= FLOW_MAX)
		return NULL;

	return &flowtab[flow_count++];
}

/**
 * flow_alloc_cancel() - Free a newly allocated flow
 * @flow:	Flow to deallocate
 *
 * @flow must be the last flow allocated by flow_alloc()
 */
void flow_alloc_cancel(union flow *flow)
{
	ASSERT(FLOW_IDX(flow) == flow_count - 1);
	memset(flow, 0, sizeof(*flow));
	flow_count--;
}

/**
 * flow_table_compact() - Perform compaction on flow table
 * @c:		Execution context
 * @hole:	Pointer to recently closed flow
 */
static void flow_table_compact(const struct ctx *c, union flow *hole)
{
	union flow *from;

	if (FLOW_IDX(hole) == --flow_count) {
		debug("flow: table compaction: maximum index was %u (%p)",
		      FLOW_IDX(hole), (void *)hole);
		memset(hole, 0, sizeof(*hole));
		return;
	}

	from = flowtab + flow_count;
	memcpy(hole, from, sizeof(*hole));

	switch (from->f.type) {
	case FLOW_TCP:
		tcp_tap_conn_update(c, &from->tcp, &hole->tcp);
		break;
	case FLOW_TCP_SPLICE:
		tcp_splice_conn_update(c, &hole->tcp_splice);
		break;
	default:
		die("Unexpected %s in tcp_table_compact()",
		    FLOW_TYPE(&from->f));
	}

	debug("flow: table compaction (%s): old index %u, new index %u, "
	      "from: %p, to: %p",
	      FLOW_TYPE(&from->f), FLOW_IDX(from), FLOW_IDX(hole),
	      (void *)from, (void *)hole);

	memset(from, 0, sizeof(*from));
}

/**
 * flow_defer_handler() - Handler for per-flow deferred and timed tasks
 * @c:		Execution context
 * @now:	Current timestamp
 */
void flow_defer_handler(const struct ctx *c, const struct timespec *now)
{
	bool timer = false;
	union flow *flow;

	if (timespec_diff_ms(now, &flow_timer_run) >= FLOW_TIMER_INTERVAL) {
		timer = true;
		flow_timer_run = *now;
	}

	for (flow = flowtab + flow_count - 1; flow >= flowtab; flow--) {
		bool closed = false;

		switch (flow->f.type) {
		case FLOW_TCP:
			closed = tcp_flow_defer(flow);
			break;
		case FLOW_TCP_SPLICE:
			closed = tcp_splice_flow_defer(flow);
			if (!closed && timer)
				tcp_splice_timer(c, flow);
			break;
		default:
			/* Assume other flow types don't need any handling */
			;
		}

		if (closed)
			flow_table_compact(c, flow);
	}
}

debug log:

solving d6650fc ...
found d6650fc in https://passt.top/passt

Code repositories for project(s) associated with this public inbox

	https://passt.top/passt

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for IMAP folder(s).