minix/servers/rs/service.c

278 lines
8.2 KiB
C

/* Utility to start or stop system services. Requests are sent to the
* reincarnation server that does the actual work.
*
* Changes:
* Jul 22, 2005: Created (Jorrit N. Herder)
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <minix/config.h>
#include <minix/com.h>
#include <minix/const.h>
#include <minix/type.h>
#include <minix/ipc.h>
#include <minix/syslib.h>
#include <sys/types.h>
#include <sys/stat.h>
/* This array defines all known requests. */
PRIVATE char *known_requests[] = {
"up",
"down",
"refresh",
"rescue",
"shutdown",
"catch for illegal requests"
};
#define ILLEGAL_REQUEST sizeof(known_requests)/sizeof(char *)
/* Global error number set for failed system calls. */
#define OK 0
extern int errno;
/* Define names for arguments provided to this utility. The first few
* arguments are required and have a known index. Thereafter, some optional
* argument pairs like "-args arglist" follow.
*/
#define ARG_NAME 0 /* own application name */
#define ARG_REQUEST 1 /* request to perform */
#define ARG_PATH 2 /* rescue dir or system service */
#define ARG_PID 2 /* pid of system service */
#define MIN_ARG_COUNT 2 /* require an action */
#define ARG_ARGS "-args" /* list of arguments to be passed */
#define ARG_DEV "-dev" /* major device number for drivers */
#define ARG_PRIV "-priv" /* required privileges */
#define ARG_PERIOD "-period" /* heartbeat period in ticks */
/* The function parse_arguments() verifies and parses the command line
* parameters passed to this utility. Request parameters that are needed
* are stored globally in the following variables:
*/
PRIVATE int req_type;
PRIVATE int req_pid;
PRIVATE char *req_path;
PRIVATE char *req_args;
PRIVATE int req_major;
PRIVATE long req_period;
PRIVATE char *req_priv;
/* Buffer to build "/command arg1 arg2 ..." string to pass to RS server. */
PRIVATE char command[4096];
/* An error occurred. Report the problem, print the usage, and exit.
*/
PRIVATE void print_usage(char *app_name, char *problem)
{
printf("Warning, %s\n", problem);
printf("Usage:\n");
printf(" %s up <binary> [%s <args>] [%s <special>] [%s <ticks>]\n",
app_name, ARG_ARGS, ARG_DEV, ARG_PERIOD);
printf(" %s down <pid>\n", app_name);
printf(" %s refresh <pid>\n", app_name);
printf(" %s rescue <dir>\n", app_name);
printf(" %s shutdown\n", app_name);
printf("\n");
}
/* A request to the RS server failed. Report and exit.
*/
PRIVATE void failure(int num)
{
printf("Request to RS failed: %s (%d)\n", strerror(num), num);
exit(num);
}
/* Parse and verify correctness of arguments. Report problem and exit if an
* error is found. Store needed parameters in global variables.
*/
PRIVATE int parse_arguments(int argc, char **argv)
{
struct stat stat_buf;
char *hz;
int req_nr;
int i;
/* Verify argument count. */
if (argc < MIN_ARG_COUNT) {
print_usage(argv[ARG_NAME], "wrong number of arguments");
exit(EINVAL);
}
/* Verify request type. */
for (req_type=0; req_type< ILLEGAL_REQUEST; req_type++) {
if (strcmp(known_requests[req_type],argv[ARG_REQUEST])==0) break;
}
if (req_type == ILLEGAL_REQUEST) {
print_usage(argv[ARG_NAME], "illegal request type");
exit(ENOSYS);
}
req_nr = RS_RQ_BASE + req_type;
if (req_nr == RS_UP) {
/* Verify argument count. */
if (argc - 1 < ARG_PATH) {
print_usage(argv[ARG_NAME], "action requires a binary to start");
exit(EINVAL);
}
/* Verify the name of the binary of the system service. */
req_path = argv[ARG_PATH];
if (req_path[0] != '/') {
print_usage(argv[ARG_NAME], "binary should be absolute path");
exit(EINVAL);
}
if (stat(req_path, &stat_buf) == -1) {
perror(req_path);
fprintf(stderr, "couldn't get stat binary\n");
exit(errno);
}
if (! (stat_buf.st_mode & S_IFREG)) {
print_usage(argv[ARG_NAME], "binary is not a regular file");
exit(EINVAL);
}
/* Check optional arguments that come in pairs like "-args arglist". */
for (i=MIN_ARG_COUNT+1; i<argc; i=i+2) {
if (! (i+1 < argc)) {
print_usage(argv[ARG_NAME], "optional argument not complete");
exit(EINVAL);
}
if (strcmp(argv[i], ARG_ARGS)==0) {
req_args = argv[i+1];
}
else if (strcmp(argv[i], ARG_PERIOD)==0) {
req_period = strtol(argv[i+1], &hz, 10);
if (strcmp(hz,"HZ")==0) req_period *= HZ;
if (req_period < 1) {
print_usage(argv[ARG_NAME], "period is at least be one tick");
exit(EINVAL);
}
}
else if (strcmp(argv[i], ARG_DEV)==0) {
if (stat(argv[i+1], &stat_buf) == -1) {
print_usage(argv[ARG_NAME], "couldn't get status of device");
exit(errno);
}
if ( ! (stat_buf.st_mode & (S_IFBLK | S_IFCHR))) {
print_usage(argv[ARG_NAME], "special file is not a device");
exit(EINVAL);
}
req_major = (stat_buf.st_rdev >> MAJOR) & BYTE;
}
else if (strcmp(argv[i], ARG_ARGS)==0) {
req_priv = argv[i+1];
}
else {
print_usage(argv[ARG_NAME], "unknown optional argument given");
exit(EINVAL);
}
}
}
else if (req_nr == RS_DOWN || req_nr == RS_REFRESH) {
/* Verify argument count. */
if (argc - 1 < ARG_PID) {
print_usage(argv[ARG_NAME], "action requires a pid to stop");
exit(EINVAL);
}
if (! (req_pid = atoi(argv[ARG_PID])) > 0) {
print_usage(argv[ARG_NAME], "pid must be greater than zero");
exit(EINVAL);
}
}
else if (req_nr == RS_RESCUE) {
/* Verify argument count. */
if (argc - 1 < ARG_PATH) {
print_usage(argv[ARG_NAME], "action requires rescue directory");
exit(EINVAL);
}
req_path = argv[ARG_PATH];
if (req_path[0] != '/') {
print_usage(argv[ARG_NAME], "rescue dir should be absolute path");
exit(EINVAL);
}
if (stat(argv[ARG_PATH], &stat_buf) == -1) {
print_usage(argv[ARG_NAME], "couldn't get status of directory");
exit(errno);
}
if ( ! (stat_buf.st_mode & S_IFDIR)) {
print_usage(argv[ARG_NAME], "file is not a directory");
exit(EINVAL);
}
}
else if (req_nr == RS_SHUTDOWN) {
/* no extra arguments required */
}
/* Return the request number if no error were found. */
return(req_nr);
}
/* Main program.
*/
PUBLIC int main(int argc, char **argv)
{
message m;
int result;
int request;
int s;
/* Verify and parse the command line arguments. All arguments are checked
* here. If an error occurs, the problem is reported and exit(2) is called.
* all needed parameters to perform the request are extracted and stored
* global variables.
*/
request = parse_arguments(argc, argv);
/* Arguments seem fine. Try to perform the request. Only valid requests
* should end up here. The default is used for not yet supported requests.
*/
switch(request) {
case RS_UP:
/* Build space-separated command string to be passed to RS server. */
strcpy(command, req_path);
command[strlen(req_path)] = ' ';
strcpy(command+strlen(req_path)+1, req_args);
/* Build request message and send the request. */
m.RS_CMD_ADDR = command;
m.RS_CMD_LEN = strlen(command);
m.RS_DEV_MAJOR = req_major;
m.RS_PERIOD = req_period;
if (OK != (s=_taskcall(RS_PROC_NR, request, &m)))
failure(s);
result = m.m_type;
break;
case RS_DOWN:
case RS_REFRESH:
m.RS_PID = req_pid;
if (OK != (s=_taskcall(RS_PROC_NR, request, &m)))
failure(s);
break;
case RS_RESCUE:
m.RS_CMD_ADDR = req_path;
m.RS_CMD_LEN = strlen(req_path);
if (OK != (s=_taskcall(RS_PROC_NR, request, &m)))
failure(s);
break;
case RS_SHUTDOWN:
if (OK != (s=_taskcall(RS_PROC_NR, request, &m)))
failure(s);
break;
default:
print_usage(argv[ARG_NAME], "request is not yet supported");
result = EGENERIC;
}
return(result);
}