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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/* SPDX-License-Identifier: LGPL-2.1+ */
#include <stdio.h>
#include <stdlib.h>
#include "alloc-util.h"
#include "bpf-firewall.h"
#include "extract-word.h"
#include "hostname-util.h"
#include "ip-address-access.h"
#include "parse-util.h"
#include "string-util.h"
int config_parse_ip_address_access(
const char *unit,
const char *filename,
unsigned line,
const char *section,
unsigned section_line,
const char *lvalue,
int ltype,
const char *rvalue,
void *data,
void *userdata) {
IPAddressAccessItem **list = data;
const char *p;
int r;
assert(list);
if (isempty(rvalue)) {
*list = ip_address_access_free_all(*list);
return 0;
}
p = rvalue;
for (;;) {
_cleanup_free_ IPAddressAccessItem *a = NULL;
_cleanup_free_ char *word = NULL;
r = extract_first_word(&p, &word, NULL, 0);
if (r == 0)
break;
if (r == -ENOMEM)
return log_oom();
if (r < 0) {
log_syntax(unit, LOG_WARNING, filename, line, r, "Invalid syntax, ignoring: %s", rvalue);
break;
}
a = new0(IPAddressAccessItem, 1);
if (!a)
return log_oom();
if (streq(word, "any")) {
/* "any" is a shortcut for 0.0.0.0/0 and ::/0 */
a->family = AF_INET;
LIST_APPEND(items, *list, a);
a = new0(IPAddressAccessItem, 1);
if (!a)
return log_oom();
a->family = AF_INET6;
} else if (is_localhost(word)) {
/* "localhost" is a shortcut for 127.0.0.0/8 and ::1/128 */
a->family = AF_INET;
a->address.in.s_addr = htobe32(0x7f000000);
a->prefixlen = 8;
LIST_APPEND(items, *list, a);
a = new0(IPAddressAccessItem, 1);
if (!a)
return log_oom();
a->family = AF_INET6;
a->address.in6 = (struct in6_addr) IN6ADDR_LOOPBACK_INIT;
a->prefixlen = 128;
} else if (streq(word, "link-local")) {
/* "link-local" is a shortcut for 169.254.0.0/16 and fe80::/64 */
a->family = AF_INET;
a->address.in.s_addr = htobe32((UINT32_C(169) << 24 | UINT32_C(254) << 16));
a->prefixlen = 16;
LIST_APPEND(items, *list, a);
a = new0(IPAddressAccessItem, 1);
if (!a)
return log_oom();
a->family = AF_INET6;
a->address.in6 = (struct in6_addr) {
.s6_addr32[0] = htobe32(0xfe800000)
};
a->prefixlen = 64;
} else if (streq(word, "multicast")) {
/* "multicast" is a shortcut for 224.0.0.0/4 and ff00::/8 */
a->family = AF_INET;
a->address.in.s_addr = htobe32((UINT32_C(224) << 24));
a->prefixlen = 4;
LIST_APPEND(items, *list, a);
a = new0(IPAddressAccessItem, 1);
if (!a)
return log_oom();
a->family = AF_INET6;
a->address.in6 = (struct in6_addr) {
.s6_addr32[0] = htobe32(0xff000000)
};
a->prefixlen = 8;
} else {
r = in_addr_prefix_from_string_auto(word, &a->family, &a->address, &a->prefixlen);
if (r < 0) {
log_syntax(unit, LOG_WARNING, filename, line, r, "Address prefix is invalid, ignoring assignment: %s", word);
return 0;
}
}
LIST_APPEND(items, *list, a);
a = NULL;
}
*list = ip_address_access_reduce(*list);
if (*list) {
r = bpf_firewall_supported();
if (r < 0)
return r;
if (r == BPF_FIREWALL_UNSUPPORTED) {
static bool warned = false;
log_full(warned ? LOG_DEBUG : LOG_WARNING,
"File %s:%u configures an IP firewall (%s=%s), but the local system does not support BPF/cgroup based firewalling.\n"
"Proceeding WITHOUT firewalling in effect! (This warning is only shown for the first loaded unit using IP firewalling.)", filename, line, lvalue, rvalue);
warned = true;
}
}
return 0;
}
IPAddressAccessItem* ip_address_access_free_all(IPAddressAccessItem *first) {
IPAddressAccessItem *next, *p = first;
while (p) {
next = p->items_next;
free(p);
p = next;
}
return NULL;
}
IPAddressAccessItem* ip_address_access_reduce(IPAddressAccessItem *first) {
IPAddressAccessItem *a, *b, *tmp;
int r;
/* Drops all entries from the list that are covered by another entry in full, thus removing all redundant
* entries. */
LIST_FOREACH_SAFE(items, a, tmp, first) {
/* Drop irrelevant bits */
(void) in_addr_mask(a->family, &a->address, a->prefixlen);
LIST_FOREACH(items, b, first) {
if (a == b)
continue;
if (a->family != b->family)
continue;
if (b->prefixlen > a->prefixlen)
continue;
r = in_addr_prefix_covers(b->family,
&b->address,
b->prefixlen,
&a->address);
if (r > 0) {
/* b covers a fully, then let's drop a */
LIST_REMOVE(items, first, a);
free(a);
break;
}
}
}
return first;
}
|
GitWeb