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 / dhcp_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(uint32_t mask)
50 mask = ntohl(mask); /* 111110000-like bit pattern */
59 /* Allocate and fill with the text of option 'option'. */
60 static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p, const char *opt_name)
62 int len, type, optlen;
69 len = option[OPT_LEN - 2];
70 type = type_p->flags & TYPE_MASK;
71 optlen = dhcp_option_lengths[type];
73 dest = ret = xmalloc(upper_length(len, type) + strlen(opt_name) + 2);
74 dest += sprintf(ret, "%s=", opt_name);
79 dest += sprintip(dest, "", option);
83 case OPTION_IP: /* Works regardless of host byte order. */
84 dest += sprintip(dest, "", option);
87 dest += sprintf(dest, *option ? "yes" : "no");
90 dest += sprintf(dest, "%u", *option);
93 memcpy(&val_u16, option, 2);
94 dest += sprintf(dest, "%u", ntohs(val_u16));
97 memcpy(&val_s16, option, 2);
98 dest += sprintf(dest, "%d", ntohs(val_s16));
101 memcpy(&val_u32, option, 4);
102 dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
105 memcpy(&val_s32, option, 4);
106 dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
109 memcpy(dest, option, len);
111 return ret; /* Short circuit this case */
112 #if ENABLE_FEATURE_RFC3397
114 /* unpack option into dest; use ret for prefix (i.e., "optname=") */
115 dest = dname_dec(option, len, ret);
123 dest += sprintf(dest, " ");
129 /* put all the parameters into an environment */
130 static char **fill_envp(struct dhcpMessage *packet)
136 const char *opt_name;
141 for (i = 0; dhcp_options[i].code; i++) {
142 if (get_option(packet, dhcp_options[i].code)) {
144 if (dhcp_options[i].code == DHCP_SUBNET)
145 num_options++; /* for mton */
150 temp = get_option(packet, DHCP_OPTION_OVER);
153 if (!(over & FILE_FIELD) && packet->file[0])
155 if (!(over & SNAME_FIELD) && packet->sname[0])
159 envp = xzalloc(sizeof(char *) * (num_options + 5));
161 envp[j++] = xasprintf("interface=%s", client_config.interface);
162 var = getenv("PATH");
164 envp[j++] = xasprintf("PATH=%s", var);
165 var = getenv("HOME");
167 envp[j++] = xasprintf("HOME=%s", var);
172 envp[j] = xmalloc(sizeof("ip=255.255.255.255"));
173 sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);
175 opt_name = dhcp_option_strings;
178 temp = get_option(packet, dhcp_options[i].code);
181 envp[j++] = alloc_fill_opts(temp, &dhcp_options[i], opt_name);
183 /* Fill in a subnet bits option for things like /24 */
184 if (dhcp_options[i].code == DHCP_SUBNET) {
186 memcpy(&subnet, temp, 4);
187 envp[j++] = xasprintf("mask=%d", mton(subnet));
190 opt_name += strlen(opt_name) + 1;
193 if (packet->siaddr) {
194 envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
195 sprintip(envp[j++], "siaddr=", (uint8_t *) &packet->siaddr);
197 if (!(over & FILE_FIELD) && packet->file[0]) {
198 /* watch out for invalid packets */
199 packet->file[sizeof(packet->file) - 1] = '\0';
200 envp[j++] = xasprintf("boot_file=%s", packet->file);
202 if (!(over & SNAME_FIELD) && packet->sname[0]) {
203 /* watch out for invalid packets */
204 packet->sname[sizeof(packet->sname) - 1] = '\0';
205 envp[j++] = xasprintf("sname=%s", packet->sname);
211 /* Call a script with a par file and env vars */
212 void FAST_FUNC udhcp_run_script(struct dhcpMessage *packet, const char *name)
217 if (client_config.script == NULL)
220 DEBUG("vfork'ing and execle'ing %s", client_config.script);
222 envp = fill_envp(packet);
225 // can we use wait4pid(spawn(...)) here?
231 execle(client_config.script, client_config.script,
233 bb_perror_msg_and_die("exec %s", client_config.script);
235 safe_waitpid(pid, NULL, 0);
236 for (curr = envp; *curr; curr++)