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.
17 /* get a rough idea of how long an option will be (rounding up...) */
18 static const int max_option_length[] = {
19 [OPTION_IP] = sizeof("255.255.255.255 "),
20 [OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
22 [OPTION_BOOLEAN] = sizeof("yes "),
23 [OPTION_U8] = sizeof("255 "),
24 [OPTION_U16] = sizeof("65535 "),
25 [OPTION_S16] = sizeof("-32768 "),
26 [OPTION_U32] = sizeof("4294967295 "),
27 [OPTION_S32] = sizeof("-2147483684 "),
31 static inline int upper_length(int length, int opt_index)
33 return max_option_length[opt_index] *
34 (length / option_lengths[opt_index]);
38 static int sprintip(char *dest, char *pre, uint8_t *ip)
40 return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);
44 /* really simple implementation, just count the bits */
45 static int mton(struct in_addr *mask)
48 unsigned long bits = ntohl(mask->s_addr);
49 /* too bad one can't check the carry bit, etc in c bit
51 for (i = 0; i < 32 && !((bits >> i) & 1); i++);
56 /* Fill dest with the text of option 'option'. */
57 static void fill_options(char *dest, uint8_t *option,
58 const struct dhcp_option *type_p)
65 int len = option[OPT_LEN - 2];
67 dest += sprintf(dest, "%s=", type_p->name);
69 type = type_p->flags & TYPE_MASK;
70 optlen = option_lengths[type];
74 dest += sprintip(dest, "", option);
78 case OPTION_IP: /* Works regardless of host byte order. */
79 dest += sprintip(dest, "", option);
82 dest += sprintf(dest, *option ? "yes" : "no");
85 dest += sprintf(dest, "%u", *option);
88 memcpy(&val_u16, option, 2);
89 dest += sprintf(dest, "%u", ntohs(val_u16));
92 memcpy(&val_s16, option, 2);
93 dest += sprintf(dest, "%d", ntohs(val_s16));
96 memcpy(&val_u32, option, 4);
97 dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
100 memcpy(&val_s32, option, 4);
101 dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
104 memcpy(dest, option, len);
106 return; /* Short circuit this case */
111 dest += sprintf(dest, " ");
116 /* put all the parameters into an environment */
117 static char **fill_envp(struct dhcpMessage *packet)
123 struct in_addr subnet;
129 for (i = 0; dhcp_options[i].code; i++)
130 if (get_option(packet, dhcp_options[i].code)) {
132 if (dhcp_options[i].code == DHCP_SUBNET)
133 num_options++; /* for mton */
135 if (packet->siaddr) num_options++;
136 if ((temp = get_option(packet, DHCP_OPTION_OVER)))
138 if (!(over & FILE_FIELD) && packet->file[0]) num_options++;
139 if (!(over & SNAME_FIELD) && packet->sname[0]) num_options++;
142 envp = xzalloc(sizeof(char *) * (num_options + 5));
144 envp[j++] = xasprintf("interface=%s", client_config.interface);
145 envp[j++] = xasprintf("PATH=%s",
146 getenv("PATH") ? : "/bin:/usr/bin:/sbin:/usr/sbin");
147 envp[j++] = xasprintf("HOME=%s", getenv("HOME") ? : "/");
149 if (packet == NULL) return envp;
151 envp[j] = xmalloc(sizeof("ip=255.255.255.255"));
152 sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);
154 for (i = 0; dhcp_options[i].code; i++) {
155 temp = get_option(packet, dhcp_options[i].code);
158 envp[j] = xmalloc(upper_length(temp[OPT_LEN - 2],
159 dhcp_options[i].flags & TYPE_MASK) + strlen(dhcp_options[i].name) + 2);
160 fill_options(envp[j++], temp, &dhcp_options[i]);
162 /* Fill in a subnet bits option for things like /24 */
163 if (dhcp_options[i].code == DHCP_SUBNET) {
164 memcpy(&subnet, temp, 4);
165 envp[j++] = xasprintf("mask=%d", mton(&subnet));
168 if (packet->siaddr) {
169 envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
170 sprintip(envp[j++], "siaddr=", (uint8_t *) &packet->siaddr);
172 if (!(over & FILE_FIELD) && packet->file[0]) {
173 /* watch out for invalid packets */
174 packet->file[sizeof(packet->file) - 1] = '\0';
175 envp[j++] = xasprintf("boot_file=%s", packet->file);
177 if (!(over & SNAME_FIELD) && packet->sname[0]) {
178 /* watch out for invalid packets */
179 packet->sname[sizeof(packet->sname) - 1] = '\0';
180 envp[j++] = xasprintf("sname=%s", packet->sname);
186 /* Call a script with a par file and env vars */
187 void udhcp_run_script(struct dhcpMessage *packet, const char *name)
192 if (client_config.script == NULL)
195 DEBUG("vfork'ing and execle'ing %s", client_config.script);
197 envp = fill_envp(packet);
201 waitpid(pid, NULL, 0);
202 for (curr = envp; *curr; curr++) free(*curr);
205 } else if (pid == 0) {
208 execle(client_config.script, client_config.script,
210 bb_perror_msg("script %s failed", client_config.script);