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.
15 #include <sys/socket.h>
16 #include <netinet/in.h>
17 #include <arpa/inet.h>
18 #include <sys/types.h>
26 /* get a rough idea of how long an option will be (rounding up...) */
27 static const int max_option_length[] = {
28 [OPTION_IP] = sizeof("255.255.255.255 "),
29 [OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
31 [OPTION_BOOLEAN] = sizeof("yes "),
32 [OPTION_U8] = sizeof("255 "),
33 [OPTION_U16] = sizeof("65535 "),
34 [OPTION_S16] = sizeof("-32768 "),
35 [OPTION_U32] = sizeof("4294967295 "),
36 [OPTION_S32] = sizeof("-2147483684 "),
40 static inline int upper_length(int length, int opt_index)
42 return max_option_length[opt_index] *
43 (length / option_lengths[opt_index]);
47 static int sprintip(char *dest, char *pre, uint8_t *ip)
49 return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);
53 /* really simple implementation, just count the bits */
54 static int mton(struct in_addr *mask)
57 unsigned long bits = ntohl(mask->s_addr);
58 /* too bad one can't check the carry bit, etc in c bit
60 for (i = 0; i < 32 && !((bits >> i) & 1); i++);
65 /* Fill dest with the text of option 'option'. */
66 static void fill_options(char *dest, uint8_t *option, struct dhcp_option *type_p)
73 int len = option[OPT_LEN - 2];
75 dest += sprintf(dest, "%s=", type_p->name);
77 type = type_p->flags & TYPE_MASK;
78 optlen = option_lengths[type];
82 dest += sprintip(dest, "", option);
86 case OPTION_IP: /* Works regardless of host byte order. */
87 dest += sprintip(dest, "", option);
90 dest += sprintf(dest, *option ? "yes" : "no");
93 dest += sprintf(dest, "%u", *option);
96 memcpy(&val_u16, option, 2);
97 dest += sprintf(dest, "%u", ntohs(val_u16));
100 memcpy(&val_s16, option, 2);
101 dest += sprintf(dest, "%d", ntohs(val_s16));
104 memcpy(&val_u32, option, 4);
105 dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
108 memcpy(&val_s32, option, 4);
109 dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
112 memcpy(dest, option, len);
114 return; /* Short circuit this case */
119 dest += sprintf(dest, " ");
124 /* put all the parameters into an environment */
125 static char **fill_envp(struct dhcpMessage *packet)
131 struct in_addr subnet;
137 for (i = 0; dhcp_options[i].code; i++)
138 if (get_option(packet, dhcp_options[i].code)) {
140 if (dhcp_options[i].code == DHCP_SUBNET)
141 num_options++; /* for mton */
143 if (packet->siaddr) num_options++;
144 if ((temp = get_option(packet, DHCP_OPTION_OVER)))
146 if (!(over & FILE_FIELD) && packet->file[0]) num_options++;
147 if (!(over & SNAME_FIELD) && packet->sname[0]) num_options++;
150 envp = xzalloc(sizeof(char *) * (num_options + 5));
152 envp[j++] = xasprintf("interface=%s", client_config.interface);
153 envp[j++] = xasprintf("PATH=%s",
154 getenv("PATH") ? : "/bin:/usr/bin:/sbin:/usr/sbin");
155 envp[j++] = xasprintf("HOME=%s", getenv("HOME") ? : "/");
157 if (packet == NULL) return envp;
159 envp[j] = xmalloc(sizeof("ip=255.255.255.255"));
160 sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);
163 for (i = 0; dhcp_options[i].code; i++) {
164 if (!(temp = get_option(packet, dhcp_options[i].code)))
166 envp[j] = xmalloc(upper_length(temp[OPT_LEN - 2],
167 dhcp_options[i].flags & TYPE_MASK) + strlen(dhcp_options[i].name) + 2);
168 fill_options(envp[j++], temp, &dhcp_options[i]);
170 /* Fill in a subnet bits option for things like /24 */
171 if (dhcp_options[i].code == DHCP_SUBNET) {
172 memcpy(&subnet, temp, 4);
173 envp[j++] = xasprintf("mask=%d", mton(&subnet));
176 if (packet->siaddr) {
177 envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
178 sprintip(envp[j++], "siaddr=", (uint8_t *) &packet->siaddr);
180 if (!(over & FILE_FIELD) && packet->file[0]) {
181 /* watch out for invalid packets */
182 packet->file[sizeof(packet->file) - 1] = '\0';
183 envp[j++] = xasprintf("boot_file=%s", packet->file);
185 if (!(over & SNAME_FIELD) && packet->sname[0]) {
186 /* watch out for invalid packets */
187 packet->sname[sizeof(packet->sname) - 1] = '\0';
188 envp[j++] = xasprintf("sname=%s", packet->sname);
194 /* Call a script with a par file and env vars */
195 void udhcp_run_script(struct dhcpMessage *packet, const char *name)
200 if (client_config.script == NULL)
203 DEBUG(LOG_INFO, "vforking and execle'ing %s", client_config.script);
205 envp = fill_envp(packet);
209 waitpid(pid, NULL, 0);
210 for (curr = envp; *curr; curr++) free(*curr);
213 } else if (pid == 0) {
217 execle(client_config.script, client_config.script,
219 LOG(LOG_ERR, "script %s failed: %m", client_config.script);