/* script.c * * Functions to call the DHCP client notification scripts * * Russ Dill 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 #include #include #include #include #include #include #include #include #include #include "options.h" #include "dhcpd.h" #include "dhcpc.h" #include "packet.h" #include "options.h" #include "debug.h" /* get a rough idea of how long an option will be (rounding up...) */ static 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 int upper_length(int length, struct dhcp_option *option) { return max_option_length[option->flags & TYPE_MASK] * (length / option_lengths[option->flags & TYPE_MASK]); } static int sprintip(char *dest, char *pre, unsigned char *ip) { return sprintf(dest, "%s%d.%d.%d.%d ", pre, ip[0], ip[1], ip[2], ip[3]); } /* Fill dest with the text of option 'option'. */ static void fill_options(char *dest, unsigned char *option, struct dhcp_option *type_p) { int type, optlen; u_int16_t val_u16; int16_t val_s16; u_int32_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; } } static char *find_env(const char *prefix, char *defaultstr) { extern char **environ; char **ptr; const int len = strlen(prefix); for (ptr = environ; *ptr != NULL; ptr++) { if (strncmp(prefix, *ptr, len) == 0) return *ptr; } return defaultstr; } /* put all the paramaters into an environment */ static char **fill_envp(struct dhcpMessage *packet) { int num_options = 0; int i, j; char **envp; unsigned char *temp; char over = 0; if (packet == NULL) num_options = 0; else { for (i = 0; options[i].code; i++) if (get_option(packet, options[i].code)) num_options++; 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 = xmalloc((num_options + 5) * sizeof(char *)); envp[0] = xmalloc(sizeof("interface=") + strlen(client_config.interface)); sprintf(envp[0], "interface=%s", client_config.interface); envp[1] = find_env("PATH", "PATH=/bin:/usr/bin:/sbin:/usr/sbin"); envp[2] = find_env("HOME", "HOME=/"); if (packet == NULL) { envp[3] = NULL; return envp; } envp[3] = xmalloc(sizeof("ip=255.255.255.255")); sprintip(envp[3], "ip=", (unsigned char *) &packet->yiaddr); for (i = 0, j = 4; options[i].code; i++) { if ((temp = get_option(packet, options[i].code))) { envp[j] = xmalloc(upper_length(temp[OPT_LEN - 2], &options[i]) + strlen(options[i].name) + 2); fill_options(envp[j], temp, &options[i]); j++; } } if (packet->siaddr) { envp[j] = xmalloc(sizeof("siaddr=255.255.255.255")); sprintip(envp[j++], "siaddr=", (unsigned char *) &packet->siaddr); } if (!(over & FILE_FIELD) && packet->file[0]) { /* watch out for invalid packets */ packet->file[sizeof(packet->file) - 1] = '\0'; envp[j] = xmalloc(sizeof("boot_file=") + strlen(packet->file)); sprintf(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'; envp[j] = xmalloc(sizeof("sname=") + strlen(packet->sname)); sprintf(envp[j++], "sname=%s", packet->sname); } envp[j] = NULL; 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; if (client_config.script == NULL) return; /* call script */ pid = fork(); if (pid) { waitpid(pid, NULL, 0); return; } else if (pid == 0) { envp = fill_envp(packet); /* close fd's? */ /* exec script */ DEBUG(LOG_INFO, "execle'ing %s", client_config.script); execle(client_config.script, client_config.script, name, NULL, envp); LOG(LOG_ERR, "script %s failed: %s", client_config.script, strerror(errno)); exit(1); } }