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
|
/* -*- mode: c; c-file-style: "openbsd" -*- */
/*
* Copyright (c) 2008 Vincent Bernat <bernat@luffy.cx>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "lldpd.h"
#include <unistd.h>
#include <net/bpf.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
int
asroot_iface_init_os(int ifindex, char *name, int *fd)
{
int enable, required, rc;
struct bpf_insn filter[] = { LLDPD_FILTER_F };
struct ifreq ifr = { .ifr_name = {} };
struct bpf_program fprog = { .bf_insns = filter,
.bf_len = sizeof(filter) / sizeof(struct bpf_insn) };
#ifndef HOST_OS_SOLARIS
int n = 0;
char dev[20];
do {
snprintf(dev, sizeof(dev), "/dev/bpf%d", n++);
*fd = open(dev, O_RDWR);
} while (*fd < 0 && errno == EBUSY);
#else
*fd = open("/dev/bpf", O_RDWR);
#endif
if (*fd < 0) {
rc = errno;
log_warn("privsep", "unable to find a free BPF");
return rc;
}
/* Set buffer size */
required = ETHER_MAX_LEN + BPF_WORDALIGN(sizeof(struct bpf_hdr));
if (ioctl(*fd, BIOCSBLEN, (caddr_t)&required) < 0) {
rc = errno;
log_warn("privsep", "unable to set receive buffer size for BPF on %s",
name);
return rc;
}
/* Bind the interface to BPF device */
strlcpy(ifr.ifr_name, name, IFNAMSIZ);
if (ioctl(*fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
rc = errno;
log_warn("privsep", "failed to bind interface %s to BPF", name);
return rc;
}
/* Disable buffering */
enable = 1;
if (ioctl(*fd, BIOCIMMEDIATE, (caddr_t)&enable) < 0) {
rc = errno;
log_warn("privsep", "unable to disable buffering for %s", name);
return rc;
}
/* Let us write the MAC address (raw packet mode) */
enable = 1;
if (ioctl(*fd, BIOCSHDRCMPLT, (caddr_t)&enable) < 0) {
rc = errno;
log_warn("privsep", "unable to set the `header complete` flag for %s",
name);
return rc;
}
/* Don't see sent packets */
#ifdef HOST_OS_OPENBSD
enable = BPF_DIRECTION_OUT;
if (ioctl(*fd, BIOCSDIRFILT, (caddr_t)&enable) < 0)
#else
enable = 0;
if (ioctl(*fd, BIOCSSEESENT, (caddr_t)&enable) < 0)
#endif
{
rc = errno;
log_warn("privsep",
"unable to set packet direction for BPF filter on %s", name);
return rc;
}
/* Install read filter */
if (ioctl(*fd, BIOCSETF, (caddr_t)&fprog) < 0) {
rc = errno;
log_warn("privsep", "unable to setup BPF filter for %s", name);
return rc;
}
#ifdef BIOCSETWF
/* Install write filter (optional) */
if (ioctl(*fd, BIOCSETWF, (caddr_t)&fprog) < 0) {
rc = errno;
log_info("privsep", "unable to setup write BPF filter for %s", name);
return rc;
}
#endif
#ifdef BIOCLOCK
/* Lock interface, but first make it non blocking since we cannot do
* this later */
levent_make_socket_nonblocking(*fd);
if (ioctl(*fd, BIOCLOCK, (caddr_t)&enable) < 0) {
rc = errno;
log_info("privsep", "unable to lock BPF interface %s", name);
return rc;
}
#endif
return 0;
}
int
asroot_iface_description_os(const char *name, const char *description)
{
#ifdef IFDESCRSIZE
# if defined HOST_OS_FREEBSD || defined HOST_OS_OPENBSD
char descr[IFDESCRSIZE];
int rc, sock = -1;
# if defined HOST_OS_FREEBSD
struct ifreq ifr = { .ifr_buffer = { .buffer = descr, .length = IFDESCRSIZE } };
# else
struct ifreq ifr = { .ifr_data = (caddr_t)descr };
# endif
strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == 1) {
rc = errno;
log_warnx("privsep", "unable to open inet socket");
return rc;
}
if (strlen(description) == 0) {
/* No neighbor, try to append "was" to the current description */
if (ioctl(sock, SIOCGIFDESCR, (caddr_t)&ifr) < 0) {
rc = errno;
log_warnx("privsep", "unable to get description of %s", name);
close(sock);
return rc;
}
if (strncmp(descr, "lldpd: ", 7) == 0) {
if (strncmp(descr + 7, "was ", 4) == 0) {
/* Already has an old neighbor */
close(sock);
return 0;
} else {
/* Append was */
memmove(descr + 11, descr + 7, sizeof(descr) - 11);
memcpy(descr, "lldpd: was ", 11);
}
} else {
/* No description, no neighbor */
strlcpy(descr, "lldpd: no neighbor", sizeof(descr));
}
} else
snprintf(descr, sizeof(descr), "lldpd: connected to %s", description);
# if defined HOST_OS_FREEBSD
ift.ifr_buffer.length = strlen(descr);
# endif
if (ioctl(sock, SIOCSIFDESCR, (caddr_t)&ifr) < 0) {
rc = errno;
log_warnx("privsep", "unable to set description of %s", name);
close(sock);
return rc;
}
close(sock);
return 0;
# endif
#endif /* IFDESCRSIZE */
static int once = 0;
if (!once) {
log_warnx("privsep", "cannot set interface description for this OS");
once = 1;
}
return 0;
}
int
asroot_iface_promisc_os(const char *name)
{
/* The promiscuous mode can be set when setting BPF
(BIOCPROMISC). Unfortunately, the interface is locked down and we
cannot change that without reopening a new socket. Let's do nothing
for now. */
return 0;
}
|
