source: MondoRescue/branches/stable/mindi-busybox/networking/udhcp/script.c@ 821

Last change on this file since 821 was 821, checked in by Bruno Cornec, 18 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)
File size: 5.6 KB
Line 
1/* script.c
2 *
3 * Functions to call the DHCP client notification scripts
4 *
5 * Russ Dill <Russ.Dill@asu.edu> July 2001
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
10#include <string.h>
11#include <unistd.h>
12#include <stdio.h>
13#include <stdlib.h>
14#include <sys/socket.h>
15#include <netinet/in.h>
16#include <arpa/inet.h>
17#include <sys/types.h>
18#include <sys/wait.h>
19
20#include "common.h"
21#include "options.h"
22#include "dhcpd.h"
23#include "dhcpc.h"
24
25/* get a rough idea of how long an option will be (rounding up...) */
26static const int max_option_length[] = {
27 [OPTION_IP] = sizeof("255.255.255.255 "),
28 [OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
29 [OPTION_STRING] = 1,
30 [OPTION_BOOLEAN] = sizeof("yes "),
31 [OPTION_U8] = sizeof("255 "),
32 [OPTION_U16] = sizeof("65535 "),
33 [OPTION_S16] = sizeof("-32768 "),
34 [OPTION_U32] = sizeof("4294967295 "),
35 [OPTION_S32] = sizeof("-2147483684 "),
36};
37
38
39static inline int upper_length(int length, int opt_index)
40{
41 return max_option_length[opt_index] *
42 (length / option_lengths[opt_index]);
43}
44
45
46static int sprintip(char *dest, char *pre, uint8_t *ip)
47{
48 return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);
49}
50
51
52/* really simple implementation, just count the bits */
53static int mton(struct in_addr *mask)
54{
55 int i;
56 unsigned long bits = ntohl(mask->s_addr);
57 /* too bad one can't check the carry bit, etc in c bit
58 * shifting */
59 for (i = 0; i < 32 && !((bits >> i) & 1); i++);
60 return 32 - i;
61}
62
63
64/* Fill dest with the text of option 'option'. */
65static void fill_options(char *dest, uint8_t *option, struct dhcp_option *type_p)
66{
67 int type, optlen;
68 uint16_t val_u16;
69 int16_t val_s16;
70 uint32_t val_u32;
71 int32_t val_s32;
72 int len = option[OPT_LEN - 2];
73
74 dest += sprintf(dest, "%s=", type_p->name);
75
76 type = type_p->flags & TYPE_MASK;
77 optlen = option_lengths[type];
78 for(;;) {
79 switch (type) {
80 case OPTION_IP_PAIR:
81 dest += sprintip(dest, "", option);
82 *(dest++) = '/';
83 option += 4;
84 optlen = 4;
85 case OPTION_IP: /* Works regardless of host byte order. */
86 dest += sprintip(dest, "", option);
87 break;
88 case OPTION_BOOLEAN:
89 dest += sprintf(dest, *option ? "yes" : "no");
90 break;
91 case OPTION_U8:
92 dest += sprintf(dest, "%u", *option);
93 break;
94 case OPTION_U16:
95 memcpy(&val_u16, option, 2);
96 dest += sprintf(dest, "%u", ntohs(val_u16));
97 break;
98 case OPTION_S16:
99 memcpy(&val_s16, option, 2);
100 dest += sprintf(dest, "%d", ntohs(val_s16));
101 break;
102 case OPTION_U32:
103 memcpy(&val_u32, option, 4);
104 dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
105 break;
106 case OPTION_S32:
107 memcpy(&val_s32, option, 4);
108 dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
109 break;
110 case OPTION_STRING:
111 memcpy(dest, option, len);
112 dest[len] = '\0';
113 return; /* Short circuit this case */
114 }
115 option += optlen;
116 len -= optlen;
117 if (len <= 0) break;
118 dest += sprintf(dest, " ");
119 }
120}
121
122
123/* put all the parameters into an environment */
124static char **fill_envp(struct dhcpMessage *packet)
125{
126 int num_options = 0;
127 int i, j;
128 char **envp;
129 uint8_t *temp;
130 struct in_addr subnet;
131 char over = 0;
132
133 if (packet == NULL)
134 num_options = 0;
135 else {
136 for (i = 0; dhcp_options[i].code; i++)
137 if (get_option(packet, dhcp_options[i].code)) {
138 num_options++;
139 if (dhcp_options[i].code == DHCP_SUBNET)
140 num_options++; /* for mton */
141 }
142 if (packet->siaddr) num_options++;
143 if ((temp = get_option(packet, DHCP_OPTION_OVER)))
144 over = *temp;
145 if (!(over & FILE_FIELD) && packet->file[0]) num_options++;
146 if (!(over & SNAME_FIELD) && packet->sname[0]) num_options++;
147 }
148
149 envp = xzalloc(sizeof(char *) * (num_options + 5));
150 j = 0;
151 envp[j++] = bb_xasprintf("interface=%s", client_config.interface);
152 envp[j++] = bb_xasprintf("PATH=%s",
153 getenv("PATH") ? : "/bin:/usr/bin:/sbin:/usr/sbin");
154 envp[j++] = bb_xasprintf("HOME=%s", getenv("HOME") ? : "/");
155
156 if (packet == NULL) return envp;
157
158 envp[j] = xmalloc(sizeof("ip=255.255.255.255"));
159 sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);
160
161
162 for (i = 0; dhcp_options[i].code; i++) {
163 if (!(temp = get_option(packet, dhcp_options[i].code)))
164 continue;
165 envp[j] = xmalloc(upper_length(temp[OPT_LEN - 2],
166 dhcp_options[i].flags & TYPE_MASK) + strlen(dhcp_options[i].name) + 2);
167 fill_options(envp[j++], temp, &dhcp_options[i]);
168
169 /* Fill in a subnet bits option for things like /24 */
170 if (dhcp_options[i].code == DHCP_SUBNET) {
171 memcpy(&subnet, temp, 4);
172 envp[j++] = bb_xasprintf("mask=%d", mton(&subnet));
173 }
174 }
175 if (packet->siaddr) {
176 envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
177 sprintip(envp[j++], "siaddr=", (uint8_t *) &packet->siaddr);
178 }
179 if (!(over & FILE_FIELD) && packet->file[0]) {
180 /* watch out for invalid packets */
181 packet->file[sizeof(packet->file) - 1] = '\0';
182 envp[j++] = bb_xasprintf("boot_file=%s", packet->file);
183 }
184 if (!(over & SNAME_FIELD) && packet->sname[0]) {
185 /* watch out for invalid packets */
186 packet->sname[sizeof(packet->sname) - 1] = '\0';
187 envp[j++] = bb_xasprintf("sname=%s", packet->sname);
188 }
189 return envp;
190}
191
192
193/* Call a script with a par file and env vars */
194void udhcp_run_script(struct dhcpMessage *packet, const char *name)
195{
196 int pid;
197 char **envp, **curr;
198
199 if (client_config.script == NULL)
200 return;
201
202 DEBUG(LOG_INFO, "vforking and execle'ing %s", client_config.script);
203
204 envp = fill_envp(packet);
205 /* call script */
206 pid = vfork();
207 if (pid) {
208 waitpid(pid, NULL, 0);
209 for (curr = envp; *curr; curr++) free(*curr);
210 free(envp);
211 return;
212 } else if (pid == 0) {
213 /* close fd's? */
214
215 /* exec script */
216 execle(client_config.script, client_config.script,
217 name, NULL, envp);
218 LOG(LOG_ERR, "script %s failed: %m", client_config.script);
219 exit(1);
220 }
221}
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