diff options
Diffstat (limited to 'networking/udhcp/script.c')
| -rw-r--r-- | networking/udhcp/script.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/networking/udhcp/script.c b/networking/udhcp/script.c new file mode 100644 index 0000000..4ce23aa --- /dev/null +++ b/networking/udhcp/script.c @@ -0,0 +1,228 @@ +/* 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 <errno.h> + +#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); + } +} |