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_UDHCP_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 /* note: ip is a pointer to an IP in network order, possibly misaliged */
41 static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
43 return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);
47 /* really simple implementation, just count the bits */
48 static int mton(uint32_t mask)
51 mask = ntohl(mask); /* 111110000-like bit pattern */
60 /* Allocate and fill with the text of option 'option'. */
61 static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p, const char *opt_name)
63 int len, type, optlen;
70 len = option[OPT_LEN - 2];
71 type = type_p->flags & TYPE_MASK;
72 optlen = dhcp_option_lengths[type];
74 dest = ret = xmalloc(upper_length(len, type) + strlen(opt_name) + 2);
75 dest += sprintf(ret, "%s=", opt_name);
80 dest += sprint_nip(dest, "", option);
84 case OPTION_IP: /* Works regardless of host byte order. */
85 dest += sprint_nip(dest, "", option);
88 dest += sprintf(dest, *option ? "yes" : "no");
91 dest += sprintf(dest, "%u", *option);
94 move_from_unaligned16(val_u16, option);
95 dest += sprintf(dest, "%u", ntohs(val_u16));
98 move_from_unaligned16(val_s16, option);
99 dest += sprintf(dest, "%d", ntohs(val_s16));
102 move_from_unaligned32(val_u32, option);
103 dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
106 move_from_unaligned32(val_s32, option);
107 dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
110 memcpy(dest, option, len);
112 return ret; /* Short circuit this case */
113 #if ENABLE_FEATURE_UDHCP_RFC3397
115 /* unpack option into dest; use ret for prefix (i.e., "optname=") */
116 dest = dname_dec(option, len, ret);
125 dest += sprintf(dest, " ");
131 /* put all the parameters into an environment */
132 static char **fill_envp(struct dhcp_packet *packet)
137 const char *opt_name;
142 for (i = 0; dhcp_options[i].code; i++) {
143 if (get_option(packet, dhcp_options[i].code)) {
145 if (dhcp_options[i].code == DHCP_SUBNET)
146 num_options++; /* for mton */
149 if (packet->siaddr_nip)
151 temp = get_option(packet, DHCP_OPTION_OVERLOAD);
154 if (!(over & FILE_FIELD) && packet->file[0])
156 if (!(over & SNAME_FIELD) && packet->sname[0])
160 curr = envp = xzalloc(sizeof(char *) * (num_options + 3));
161 *curr = xasprintf("interface=%s", client_config.interface);
167 *curr = xmalloc(sizeof("ip=255.255.255.255"));
168 sprint_nip(*curr, "ip=", (uint8_t *) &packet->yiaddr);
171 opt_name = dhcp_option_strings;
174 temp = get_option(packet, dhcp_options[i].code);
177 *curr = alloc_fill_opts(temp, &dhcp_options[i], opt_name);
180 /* Fill in a subnet bits option for things like /24 */
181 if (dhcp_options[i].code == DHCP_SUBNET) {
183 move_from_unaligned32(subnet, temp);
184 *curr = xasprintf("mask=%d", mton(subnet));
188 opt_name += strlen(opt_name) + 1;
191 if (packet->siaddr_nip) {
192 *curr = xmalloc(sizeof("siaddr=255.255.255.255"));
193 sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
196 if (!(over & FILE_FIELD) && packet->file[0]) {
197 /* watch out for invalid packets */
198 packet->file[sizeof(packet->file) - 1] = '\0';
199 *curr = 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 *curr = xasprintf("sname=%s", packet->sname);
212 /* Call a script with a par file and env vars */
213 void FAST_FUNC udhcp_run_script(struct dhcp_packet *packet, const char *name)
218 if (client_config.script == NULL)
221 envp = fill_envp(packet);
224 log1("Executing %s", client_config.script);
225 argv[0] = (char*) client_config.script;
226 argv[1] = (char*) name;
228 wait4pid(spawn(argv));
230 for (curr = envp; *curr; curr++) {