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-rw-r--r--networking/udhcp/script.c234
1 files changed, 234 insertions, 0 deletions
diff --git a/networking/udhcp/script.c b/networking/udhcp/script.c
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+++ b/networking/udhcp/script.c
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+/* script.c
+ *
+ * Functions to call the DHCP client notification scripts
+ *
+ * Russ Dill <Russ.Dill@asu.edu> July 2001
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "common.h"
+#include "options.h"
+#include "dhcpd.h"
+#include "dhcpc.h"
+#include "script.h"
+
+/* get a rough idea of how long an option will be (rounding up...) */
+static const int max_option_length[] = {
+ [OPTION_IP] = sizeof("255.255.255.255 "),
+ [OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
+ [OPTION_STRING] = 1,
+ [OPTION_BOOLEAN] = sizeof("yes "),
+ [OPTION_U8] = sizeof("255 "),
+ [OPTION_U16] = sizeof("65535 "),
+ [OPTION_S16] = sizeof("-32768 "),
+ [OPTION_U32] = sizeof("4294967295 "),
+ [OPTION_S32] = sizeof("-2147483684 "),
+};
+
+
+static inline int upper_length(int length, int opt_index)
+{
+ return max_option_length[opt_index] *
+ (length / option_lengths[opt_index]);
+}
+
+
+static int sprintip(char *dest, char *pre, uint8_t *ip)
+{
+ return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);
+}
+
+
+/* really simple implementation, just count the bits */
+static int mton(struct in_addr *mask)
+{
+ int i;
+ unsigned long bits = ntohl(mask->s_addr);
+ /* too bad one can't check the carry bit, etc in c bit
+ * shifting */
+ for (i = 0; i < 32 && !((bits >> i) & 1); i++);
+ return 32 - i;
+}
+
+
+/* Fill dest with the text of option 'option'. */
+static void fill_options(char *dest, uint8_t *option, struct dhcp_option *type_p)
+{
+ int type, optlen;
+ uint16_t val_u16;
+ int16_t val_s16;
+ uint32_t val_u32;
+ int32_t val_s32;
+ int len = option[OPT_LEN - 2];
+
+ dest += sprintf(dest, "%s=", type_p->name);
+
+ type = type_p->flags & TYPE_MASK;
+ optlen = option_lengths[type];
+ for(;;) {
+ switch (type) {
+ case OPTION_IP_PAIR:
+ dest += sprintip(dest, "", option);
+ *(dest++) = '/';
+ option += 4;
+ optlen = 4;
+ case OPTION_IP: /* Works regardless of host byte order. */
+ dest += sprintip(dest, "", option);
+ break;
+ case OPTION_BOOLEAN:
+ dest += sprintf(dest, *option ? "yes" : "no");
+ break;
+ case OPTION_U8:
+ dest += sprintf(dest, "%u", *option);
+ break;
+ case OPTION_U16:
+ memcpy(&val_u16, option, 2);
+ dest += sprintf(dest, "%u", ntohs(val_u16));
+ break;
+ case OPTION_S16:
+ memcpy(&val_s16, option, 2);
+ dest += sprintf(dest, "%d", ntohs(val_s16));
+ break;
+ case OPTION_U32:
+ memcpy(&val_u32, option, 4);
+ dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
+ break;
+ case OPTION_S32:
+ memcpy(&val_s32, option, 4);
+ dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
+ break;
+ case OPTION_STRING:
+ memcpy(dest, option, len);
+ dest[len] = '\0';
+ return; /* Short circuit this case */
+ }
+ option += optlen;
+ len -= optlen;
+ if (len <= 0) break;
+ dest += sprintf(dest, " ");
+ }
+}
+
+
+/* put all the parameters into an environment */
+static char **fill_envp(struct dhcpMessage *packet)
+{
+ int num_options = 0;
+ int i, j;
+ char **envp;
+ uint8_t *temp;
+ struct in_addr subnet;
+ char over = 0;
+
+ if (packet == NULL)
+ num_options = 0;
+ else {
+ for (i = 0; dhcp_options[i].code; i++)
+ if (get_option(packet, dhcp_options[i].code)) {
+ num_options++;
+ if (dhcp_options[i].code == DHCP_SUBNET)
+ num_options++; /* for mton */
+ }
+ if (packet->siaddr) num_options++;
+ if ((temp = get_option(packet, DHCP_OPTION_OVER)))
+ over = *temp;
+ if (!(over & FILE_FIELD) && packet->file[0]) num_options++;
+ if (!(over & SNAME_FIELD) && packet->sname[0]) num_options++;
+ }
+
+ envp = xcalloc(sizeof(char *), num_options + 5);
+ j = 0;
+ asprintf(&envp[j++], "interface=%s", client_config.interface);
+ asprintf(&envp[j++], "%s=%s", "PATH",
+ getenv("PATH") ? : "/bin:/usr/bin:/sbin:/usr/sbin");
+ asprintf(&envp[j++], "%s=%s", "HOME", getenv("HOME") ? : "/");
+
+ if (packet == NULL) return envp;
+
+ envp[j] = xmalloc(sizeof("ip=255.255.255.255"));
+ sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);
+
+
+ for (i = 0; dhcp_options[i].code; i++) {
+ if (!(temp = get_option(packet, dhcp_options[i].code)))
+ continue;
+ envp[j] = xmalloc(upper_length(temp[OPT_LEN - 2],
+ dhcp_options[i].flags & TYPE_MASK) + strlen(dhcp_options[i].name) + 2);
+ fill_options(envp[j++], temp, &dhcp_options[i]);
+
+ /* Fill in a subnet bits option for things like /24 */
+ if (dhcp_options[i].code == DHCP_SUBNET) {
+ memcpy(&subnet, temp, 4);
+ asprintf(&envp[j++], "mask=%d", mton(&subnet));
+ }
+ }
+ if (packet->siaddr) {
+ envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
+ sprintip(envp[j++], "siaddr=", (uint8_t *) &packet->siaddr);
+ }
+ if (!(over & FILE_FIELD) && packet->file[0]) {
+ /* watch out for invalid packets */
+ packet->file[sizeof(packet->file) - 1] = '\0';
+ asprintf(&envp[j++], "boot_file=%s", packet->file);
+ }
+ if (!(over & SNAME_FIELD) && packet->sname[0]) {
+ /* watch out for invalid packets */
+ packet->sname[sizeof(packet->sname) - 1] = '\0';
+ asprintf(&envp[j++], "sname=%s", packet->sname);
+ }
+ return envp;
+}
+
+
+/* Call a script with a par file and env vars */
+void run_script(struct dhcpMessage *packet, const char *name)
+{
+ int pid;
+ char **envp, **curr;
+
+ if (client_config.script == NULL)
+ return;
+
+ DEBUG(LOG_INFO, "vforking and execle'ing %s", client_config.script);
+
+ envp = fill_envp(packet);
+ /* call script */
+ pid = vfork();
+ if (pid) {
+ waitpid(pid, NULL, 0);
+ for (curr = envp; *curr; curr++) free(*curr);
+ free(envp);
+ return;
+ } else if (pid == 0) {
+ /* close fd's? */
+
+ /* exec script */
+ execle(client_config.script, client_config.script,
+ name, NULL, envp);
+ LOG(LOG_ERR, "script %s failed: %m", client_config.script);
+ exit(1);
+ }
+}