1 /* vi: set sw=4 ts=4: */
4 * Functions to call the DHCP client notification scripts
6 * Russ Dill <Russ.Dill@asu.edu> July 2001
8 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
16 /* get a rough idea of how long an option will be (rounding up...) */
17 static const uint8_t max_option_length[] = {
18 [OPTION_IP] = sizeof("255.255.255.255 "),
19 [OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
21 #if ENABLE_FEATURE_RFC3397
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 "),
33 static inline int upper_length(int length, int opt_index)
35 return max_option_length[opt_index] *
36 (length / option_lengths[opt_index]);
40 static int sprintip(char *dest, const char *pre, const uint8_t *ip)
42 return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);
46 /* really simple implementation, just count the bits */
47 static int mton(struct in_addr *mask)
50 unsigned long bits = ntohl(mask->s_addr);
51 /* too bad one can't check the carry bit, etc in c bit
53 for (i = 0; i < 32 && !((bits >> i) & 1); i++);
58 /* Allocate and fill with the text of option 'option'. */
59 static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p)
61 int len, type, optlen;
68 len = option[OPT_LEN - 2];
69 type = type_p->flags & TYPE_MASK;
70 optlen = option_lengths[type];
72 dest = ret = xmalloc(upper_length(len, type) + strlen(type_p->name) + 2);
73 dest += sprintf(ret, "%s=", type_p->name);
78 dest += sprintip(dest, "", option);
82 case OPTION_IP: /* Works regardless of host byte order. */
83 dest += sprintip(dest, "", option);
86 dest += sprintf(dest, *option ? "yes" : "no");
89 dest += sprintf(dest, "%u", *option);
92 memcpy(&val_u16, option, 2);
93 dest += sprintf(dest, "%u", ntohs(val_u16));
96 memcpy(&val_s16, option, 2);
97 dest += sprintf(dest, "%d", ntohs(val_s16));
100 memcpy(&val_u32, option, 4);
101 dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
104 memcpy(&val_s32, option, 4);
105 dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
108 memcpy(dest, option, len);
110 return ret; /* Short circuit this case */
111 #if ENABLE_FEATURE_RFC3397
113 /* unpack option into dest; use ret for prefix (i.e., "optname=") */
114 dest = dname_dec(option, len, ret);
122 dest += sprintf(dest, " ");
128 /* put all the parameters into an environment */
129 static char **fill_envp(struct dhcpMessage *packet)
136 struct in_addr subnet;
140 for (i = 0; dhcp_options[i].code; i++) {
141 if (get_option(packet, dhcp_options[i].code)) {
143 if (dhcp_options[i].code == DHCP_SUBNET)
144 num_options++; /* for mton */
149 temp = get_option(packet, DHCP_OPTION_OVER);
152 if (!(over & FILE_FIELD) && packet->file[0])
154 if (!(over & SNAME_FIELD) && packet->sname[0])
158 envp = xzalloc(sizeof(char *) * (num_options + 5));
160 envp[j++] = xasprintf("interface=%s", client_config.interface);
161 var = getenv("PATH");
163 envp[j++] = xasprintf("PATH=%s", var);
164 var = getenv("HOME");
166 envp[j++] = xasprintf("HOME=%s", var);
171 envp[j] = xmalloc(sizeof("ip=255.255.255.255"));
172 sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);
174 for (i = 0; dhcp_options[i].code; i++) {
175 temp = get_option(packet, dhcp_options[i].code);
178 envp[j++] = alloc_fill_opts(temp, &dhcp_options[i]);
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));
186 if (packet->siaddr) {
187 envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
188 sprintip(envp[j++], "siaddr=", (uint8_t *) &packet->siaddr);
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);
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);
204 /* Call a script with a par file and env vars */
205 void udhcp_run_script(struct dhcpMessage *packet, const char *name)
210 if (client_config.script == NULL)
213 DEBUG("vfork'ing and execle'ing %s", client_config.script);
215 envp = fill_envp(packet);
218 // can we use wait4pid(spawn(...)) here?
224 execle(client_config.script, client_config.script,
226 bb_perror_msg_and_die("script %s failed", client_config.script);
228 waitpid(pid, NULL, 0);
229 for (curr = envp; *curr; curr++)