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
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
|
/* script.c
*
* Functions to call the DHCP client notification scripts
*
* Russ Dill <Russ.Dill@asu.edu> July 2001
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include "options.h"
#include "dhcpd.h"
#include "dhcpc.h"
#include "packet.h"
#include "options.h"
#include "debug.h"
#include "config.h"
/* get a rough idea of how long an option will be (rounding up...) */
static int max_option_length[] = {
[OPTION_IP] = sizeof("255.255.255.255 "),
[OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
[OPTION_STRING] = 1,
[OPTION_BOOLEAN] = sizeof("yes "),
[OPTION_U8] = sizeof("255 "),
[OPTION_U16] = sizeof("65535 "),
[OPTION_S16] = sizeof("-32768 "),
[OPTION_U32] = sizeof("4294967295 "),
[OPTION_S32] = sizeof("-2147483684 "),
};
static int upper_length(int length, struct dhcp_option *option)
{
return max_option_length[option->flags & TYPE_MASK] *
(length / option_lengths[option->flags & TYPE_MASK]);
}
static int sprintip(char *dest, char *pre, unsigned char *ip) {
return sprintf(dest, "%s%d.%d.%d.%d ", pre, ip[0], ip[1], ip[2], ip[3]);
}
#ifdef CONFIG_FEATURE_UDHCPC_IP
/* convert a netmask (255.255.255.0) into the length (24) */
static int inet_ntom (const char *src, short *dst)
{
in_addr_t mask, num;
mask = ntohl(*(unsigned int *)src);
for (num = mask; num & 1; num >>= 1);
if (num != 0 && mask != 0)
{
for (num = ~mask; num & 1; num >>= 1);
if (num)
return 0;
}
for (num = 0; mask; mask <<= 1)
num++;
*dst = num;
return 1;
}
static int sprintprefix(char *dest, char *pre, unsigned char *ip) {
short sdest = 0;
inet_ntom(ip, &sdest);
return sprintf(dest, "%s%hd ", pre, sdest);
}
#endif
/* Fill dest with the text of option 'option'. */
static void fill_options(char *dest, unsigned char *option, struct dhcp_option *type_p)
{
int type, optlen;
u_int16_t val_u16;
int16_t val_s16;
u_int32_t val_u32;
int32_t val_s32;
int len = option[OPT_LEN - 2];
dest += sprintf(dest, "%s=", type_p->name);
type = type_p->flags & TYPE_MASK;
optlen = option_lengths[type];
for(;;) {
switch (type) {
case OPTION_IP_PAIR:
dest += sprintip(dest, "", option);
*(dest++) = '/';
option += 4;
optlen = 4;
#ifndef CONFIG_FEATURE_UDHCPC_IP
case OPTION_IP: /* Works regardless of host byte order. */
#endif
dest += sprintip(dest, "", option);
break;
#ifdef CONFIG_FEATURE_UDHCPC_IP
case OPTION_IP: /* Works regardless of host byte order. */
if (type_p->flags & OPTION_PREFIX) {
dest += sprintprefix(dest, "", option);
} else {
dest += sprintip(dest, "", option);
}
break;
#endif
case OPTION_BOOLEAN:
dest += sprintf(dest, *option ? "yes " : "no ");
break;
case OPTION_U8:
dest += sprintf(dest, "%u ", *option);
break;
case OPTION_U16:
memcpy(&val_u16, option, 2);
dest += sprintf(dest, "%u ", ntohs(val_u16));
break;
case OPTION_S16:
memcpy(&val_s16, option, 2);
dest += sprintf(dest, "%d ", ntohs(val_s16));
break;
case OPTION_U32:
memcpy(&val_u32, option, 4);
dest += sprintf(dest, "%lu ", (unsigned long) ntohl(val_u32));
break;
case OPTION_S32:
memcpy(&val_s32, option, 4);
dest += sprintf(dest, "%ld ", (long) ntohl(val_s32));
break;
case OPTION_STRING:
memcpy(dest, option, len);
dest[len] = '\0';
return; /* Short circuit this case */
}
option += optlen;
len -= optlen;
if (len <= 0) break;
}
}
static char *find_env(const char *prefix, char *defaultstr)
{
extern char **environ;
char **ptr;
const int len = strlen(prefix);
for (ptr = environ; *ptr != NULL; ptr++) {
if (strncmp(prefix, *ptr, len) == 0)
return *ptr;
}
return defaultstr;
}
/* put all the paramaters into an environment */
static char **fill_envp(struct dhcpMessage *packet)
{
int num_options = 0;
int i, j;
char **envp;
unsigned char *temp;
char over = 0;
if (packet == NULL)
num_options = 0;
else {
for (i = 0; options[i].code; i++)
if (get_option(packet, options[i].code))
num_options++;
if (packet->siaddr) num_options++;
if ((temp = get_option(packet, DHCP_OPTION_OVER)))
over = *temp;
if (!(over & FILE_FIELD) && packet->file[0]) num_options++;
if (!(over & SNAME_FIELD) && packet->sname[0]) num_options++;
}
envp = xmalloc((num_options + 5) * sizeof(char *));
envp[0] = xmalloc(sizeof("interface=") + strlen(client_config.interface));
sprintf(envp[0], "interface=%s", client_config.interface);
envp[1] = find_env("PATH", "PATH=/bin:/usr/bin:/sbin:/usr/sbin");
envp[2] = find_env("HOME", "HOME=/");
if (packet == NULL) {
envp[3] = NULL;
return envp;
}
envp[3] = xmalloc(sizeof("ip=255.255.255.255"));
sprintip(envp[3], "ip=", (unsigned char *) &packet->yiaddr);
for (i = 0, j = 4; options[i].code; i++) {
if ((temp = get_option(packet, options[i].code))) {
envp[j] = xmalloc(upper_length(temp[OPT_LEN - 2], &options[i]) + strlen(options[i].name) + 2);
fill_options(envp[j], temp, &options[i]);
j++;
}
}
if (packet->siaddr) {
envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
sprintip(envp[j++], "siaddr=", (unsigned char *) &packet->siaddr);
}
if (!(over & FILE_FIELD) && packet->file[0]) {
/* watch out for invalid packets */
packet->file[sizeof(packet->file) - 1] = '\0';
envp[j] = xmalloc(sizeof("boot_file=") + strlen(packet->file));
sprintf(envp[j++], "boot_file=%s", packet->file);
}
if (!(over & SNAME_FIELD) && packet->sname[0]) {
/* watch out for invalid packets */
packet->sname[sizeof(packet->sname) - 1] = '\0';
envp[j] = xmalloc(sizeof("sname=") + strlen(packet->sname));
sprintf(envp[j++], "sname=%s", packet->sname);
}
envp[j] = NULL;
return envp;
}
/* Call a script with a par file and env vars */
void run_script(struct dhcpMessage *packet, const char *name)
{
int pid;
char **envp;
if (client_config.script == NULL)
return;
/* call script */
pid = fork();
if (pid) {
waitpid(pid, NULL, 0);
return;
} else if (pid == 0) {
envp = fill_envp(packet);
/* close fd's? */
/* exec script */
DEBUG(LOG_INFO, "execle'ing %s", client_config.script);
execle(client_config.script, client_config.script,
name, NULL, envp);
LOG(LOG_ERR, "script %s failed: %s",
client_config.script, strerror(errno));
exit(1);
}
}
|
