source: MondoRescue/branches/2.2.9/mindi-busybox/networking/udhcp/script.c@ 3320

Last change on this file since 3320 was 3320, checked in by Bruno Cornec, 9 years ago
  • Re-add (thanks git BTW) the 2.2.9 branch which had been destroyed in the move to 3.0
  • Property svn:eol-style set to native
File size: 5.7 KB
Line 
1/* vi: set sw=4 ts=4: */
2/* script.c
3 *
4 * Functions to call the DHCP client notification scripts
5 *
6 * Russ Dill <Russ.Dill@asu.edu> July 2001
7 *
8 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9 */
10
11#include "common.h"
12#include "dhcpc.h"
13#include "options.h"
14
15
16/* get a rough idea of how long an option will be (rounding up...) */
17static const uint8_t max_option_length[] = {
18 [OPTION_IP] = sizeof("255.255.255.255 "),
19 [OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
20 [OPTION_STRING] = 1,
21#if ENABLE_FEATURE_RFC3397
22 [OPTION_STR1035] = 1,
23#endif
24 [OPTION_BOOLEAN] = sizeof("yes "),
25 [OPTION_U8] = sizeof("255 "),
26 [OPTION_U16] = sizeof("65535 "),
27 [OPTION_S16] = sizeof("-32768 "),
28 [OPTION_U32] = sizeof("4294967295 "),
29 [OPTION_S32] = sizeof("-2147483684 "),
30};
31
32
33static inline int upper_length(int length, int opt_index)
34{
35 return max_option_length[opt_index] *
36 (length / option_lengths[opt_index]);
37}
38
39
40static int sprintip(char *dest, const char *pre, const uint8_t *ip)
41{
42 return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);
43}
44
45
46/* really simple implementation, just count the bits */
47static int mton(struct in_addr *mask)
48{
49 int i;
50 unsigned long bits = ntohl(mask->s_addr);
51 /* too bad one can't check the carry bit, etc in c bit
52 * shifting */
53 for (i = 0; i < 32 && !((bits >> i) & 1); i++);
54 return 32 - i;
55}
56
57
58/* Allocate and fill with the text of option 'option'. */
59static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p)
60{
61 int len, type, optlen;
62 uint16_t val_u16;
63 int16_t val_s16;
64 uint32_t val_u32;
65 int32_t val_s32;
66 char *dest, *ret;
67
68 len = option[OPT_LEN - 2];
69 type = type_p->flags & TYPE_MASK;
70 optlen = option_lengths[type];
71
72 dest = ret = xmalloc(upper_length(len, type) + strlen(type_p->name) + 2);
73 dest += sprintf(ret, "%s=", type_p->name);
74
75 for (;;) {
76 switch (type) {
77 case OPTION_IP_PAIR:
78 dest += sprintip(dest, "", option);
79 *dest++ = '/';
80 option += 4;
81 optlen = 4;
82 case OPTION_IP: /* Works regardless of host byte order. */
83 dest += sprintip(dest, "", option);
84 break;
85 case OPTION_BOOLEAN:
86 dest += sprintf(dest, *option ? "yes" : "no");
87 break;
88 case OPTION_U8:
89 dest += sprintf(dest, "%u", *option);
90 break;
91 case OPTION_U16:
92 memcpy(&val_u16, option, 2);
93 dest += sprintf(dest, "%u", ntohs(val_u16));
94 break;
95 case OPTION_S16:
96 memcpy(&val_s16, option, 2);
97 dest += sprintf(dest, "%d", ntohs(val_s16));
98 break;
99 case OPTION_U32:
100 memcpy(&val_u32, option, 4);
101 dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
102 break;
103 case OPTION_S32:
104 memcpy(&val_s32, option, 4);
105 dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
106 break;
107 case OPTION_STRING:
108 memcpy(dest, option, len);
109 dest[len] = '\0';
110 return ret; /* Short circuit this case */
111#if ENABLE_FEATURE_RFC3397
112 case OPTION_STR1035:
113 /* unpack option into dest; use ret for prefix (i.e., "optname=") */
114 dest = dname_dec(option, len, ret);
115 free(ret);
116 return dest;
117#endif
118 }
119 option += optlen;
120 len -= optlen;
121 if (len <= 0) break;
122 dest += sprintf(dest, " ");
123 }
124 return ret;
125}
126
127
128/* put all the parameters into an environment */
129static char **fill_envp(struct dhcpMessage *packet)
130{
131 int num_options = 0;
132 int i, j;
133 char **envp;
134 char *var;
135 uint8_t *temp;
136 struct in_addr subnet;
137 char over = 0;
138
139 if (packet) {
140 for (i = 0; dhcp_options[i].code; i++) {
141 if (get_option(packet, dhcp_options[i].code)) {
142 num_options++;
143 if (dhcp_options[i].code == DHCP_SUBNET)
144 num_options++; /* for mton */
145 }
146 }
147 if (packet->siaddr)
148 num_options++;
149 temp = get_option(packet, DHCP_OPTION_OVER);
150 if (temp)
151 over = *temp;
152 if (!(over & FILE_FIELD) && packet->file[0])
153 num_options++;
154 if (!(over & SNAME_FIELD) && packet->sname[0])
155 num_options++;
156 }
157
158 envp = xzalloc(sizeof(char *) * (num_options + 5));
159 j = 0;
160 envp[j++] = xasprintf("interface=%s", client_config.interface);
161 var = getenv("PATH");
162 if (var)
163 envp[j++] = xasprintf("PATH=%s", var);
164 var = getenv("HOME");
165 if (var)
166 envp[j++] = xasprintf("HOME=%s", var);
167
168 if (packet == NULL)
169 return envp;
170
171 envp[j] = xmalloc(sizeof("ip=255.255.255.255"));
172 sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);
173
174 for (i = 0; dhcp_options[i].code; i++) {
175 temp = get_option(packet, dhcp_options[i].code);
176 if (!temp)
177 continue;
178 envp[j++] = alloc_fill_opts(temp, &dhcp_options[i]);
179
180 /* Fill in a subnet bits option for things like /24 */
181 if (dhcp_options[i].code == DHCP_SUBNET) {
182 memcpy(&subnet, temp, 4);
183 envp[j++] = xasprintf("mask=%d", mton(&subnet));
184 }
185 }
186 if (packet->siaddr) {
187 envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
188 sprintip(envp[j++], "siaddr=", (uint8_t *) &packet->siaddr);
189 }
190 if (!(over & FILE_FIELD) && packet->file[0]) {
191 /* watch out for invalid packets */
192 packet->file[sizeof(packet->file) - 1] = '\0';
193 envp[j++] = xasprintf("boot_file=%s", packet->file);
194 }
195 if (!(over & SNAME_FIELD) && packet->sname[0]) {
196 /* watch out for invalid packets */
197 packet->sname[sizeof(packet->sname) - 1] = '\0';
198 envp[j++] = xasprintf("sname=%s", packet->sname);
199 }
200 return envp;
201}
202
203
204/* Call a script with a par file and env vars */
205void udhcp_run_script(struct dhcpMessage *packet, const char *name)
206{
207 int pid;
208 char **envp, **curr;
209
210 if (client_config.script == NULL)
211 return;
212
213 DEBUG("vfork'ing and execle'ing %s", client_config.script);
214
215 envp = fill_envp(packet);
216
217 /* call script */
218// can we use wait4pid(spawn(...)) here?
219 pid = vfork();
220 if (pid < 0) return;
221 if (pid == 0) {
222 /* close fd's? */
223 /* exec script */
224 execle(client_config.script, client_config.script,
225 name, NULL, envp);
226 bb_perror_msg_and_die("script %s failed", client_config.script);
227 }
228 waitpid(pid, NULL, 0);
229 for (curr = envp; *curr; curr++)
230 free(*curr);
231 free(envp);
232}
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