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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
| | // SPDX-License-Identifier: GPL-2.0-or-later
/* PASST - Plug A Simple Socket Transport
* for qemu/UNIX domain socket mode
*
* PASTA - Pack A Subtle Tap Abstraction
* for network namespace/tap device mode
*
* packet.c - Packet abstraction: add packets to pool, flush, get packet data
*
* Copyright (c) 2020-2021 Red Hat GmbH
* Author: Stefano Brivio <sbrivio@redhat.com>
*/
#include <limits.h>
#include <stddef.h>
#include <stdint.h>
#include <netinet/ip6.h>
#include "packet.h"
#include "util.h"
#include "log.h"
/**
* packet_check_range() - Check if a memory range is valid for a pool
* @p: Packet pool
* @ptr: Start of desired data range
* @len: Length of desired data range
* @func: For tracing: name of calling function
* @line: For tracing: caller line of function call
*
* Return: 0 if the range is valid, -1 otherwise
*/
static int packet_check_range(const struct pool *p, const char *ptr, size_t len,
const char *func, int line)
{
if (len > PACKET_MAX_LEN) {
debug("packet range length %zu (max %zu), %s:%i",
len, PACKET_MAX_LEN, func, line);
return -1;
}
if (p->buf_size == 0) {
int ret;
ret = vu_packet_check_range((void *)p->buf, ptr, len);
if (ret == -1)
debug("cannot find region, %s:%i", func, line);
return ret;
}
if (ptr < p->buf) {
debug("packet range start %p before buffer start %p, %s:%i",
(void *)ptr, (void *)p->buf, func, line);
return -1;
}
if (len > p->buf_size) {
debug("packet range length %zu larger than buffer %zu, %s:%i",
len, p->buf_size, func, line);
return -1;
}
if ((size_t)(ptr - p->buf) > p->buf_size - len) {
debug("packet range %p, len %zu after buffer end %p, %s:%i",
(void *)ptr, len, (void *)(p->buf + p->buf_size),
func, line);
return -1;
}
return 0;
}
/**
* pool_full() - Is a packet pool full?
* @p: Pointer to packet pool
*
* Return: true if the pool is full, false if more packets can be added
*/
bool pool_full(const struct pool *p)
{
return p->count >= p->size;
}
/**
* packet_add_do() - Add data as packet descriptor to given pool
* @p: Existing pool
* @data: Data to add
* @func: For tracing: name of calling function
* @line: For tracing: caller line of function call
*/
void packet_add_do(struct pool *p, struct iov_tail *data,
const char *func, int line)
{
size_t idx = p->count;
const char *start;
size_t len;
if (pool_full(p)) {
debug("add packet index %zu to pool with size %zu, %s:%i",
idx, p->size, func, line);
return;
}
if (!iov_tail_prune(data))
return;
ASSERT(data->cnt == 1); /* we don't support iovec */
len = data->iov[0].iov_len - data->off;
start = (char *)data->iov[0].iov_base + data->off;
if (packet_check_range(p, start, len, func, line))
return;
p->pkt[idx].iov_base = (void *)start;
p->pkt[idx].iov_len = len;
p->count++;
}
/**
* packet_data_do() - Get data range from packet descriptor from given pool
* @p: Packet pool
* @idx: Index of packet descriptor in pool
* @data: IOV tail to store the address of the data (output)
* @func: For tracing: name of calling function, NULL means no trace()
* @line: For tracing: caller line of function call
*
* Return: true if @data contains valid data, false otherwise
*/
bool packet_data_do(const struct pool *p, size_t idx,
struct iov_tail *data,
const char *func, int line)
{
size_t i;
ASSERT_WITH_MSG(p->count <= p->size,
"Corrupt pool count: %zu, size: %zu, %s:%i",
p->count, p->size, func, line);
if (idx >= p->count) {
debug("packet %zu from pool size: %zu, count: %zu, "
"%s:%i", idx, p->size, p->count, func, line);
return false;
}
data->cnt = 1;
data->off = 0;
data->iov = &p->pkt[idx];
for (i = 0; i < data->cnt; i++) {
ASSERT_WITH_MSG(!packet_check_range(p, data->iov[i].iov_base,
data->iov[i].iov_len,
func, line),
"Corrupt packet pool, %s:%i", func, line);
}
return true;
}
/**
* pool_flush() - Flush a packet pool
* @p: Pointer to packet pool
*/
void pool_flush(struct pool *p)
{
p->count = 0;
}
|