/*
 * Usage: as CGI script, but called by userv
 * environment variables are USERV_U_E_...
 */

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stat.h>

#include "ucgi.h"

void *xrealloc(void *ptr, size_t sz) {
  void *r;

  r= realloc(ptr,sz);
  if (!r) syserror("realloc failed");
  return r;
}

int main(int argc, const char **argv) {
  char *uservar, *scriptpath;
  const char *nextslash, *lastslash, *pathi, *ev, *en, *scriptdir;
  const char *const *ep;
  const char **arguments;
  size_t scriptdirlen, scriptpathlen, l, uservarnl;
  struct stat stab;

  ev= getenv("USERV_U_DEBUG");
  if (ev && *ev) debugmode= 1;
  
  if (argc > MAX_ARGS) error("too many arguments");

  scriptdir= *++argv;
  if (!scriptdir) error("no argv[1] (script directory)");
  scriptdirlen= strlen(scriptdir);

  for (ep= envok; (en= *ep); ep++) {
    l= strlen(en)+11;
    if (uservarnl<l) { uservarn= xrealloc(uservarn,l); uservarnl= l; }
    sprintf(uservarn,"USERV_U_E_%s",en);
    ev= getenv(uservarn); if (!ev) continue;
    if (strlen(ev) > MAX_ENVVAR_VALUE) error("environment variable too long");
    if (setenv(en,ev,1)) syserror("setenv");
    if (unsetenv(uservarn)) syserror("unsetenv");
  }

  pathi= getenv("PATH_INFO");
  if (!pathi) error("PATH_INFO not found");
  if (pathi[0] != '/') error("PATH_INFO must start with /");
  lastslash= pathi;
  for (;;) {
    nextslash= strchr(lastslash+1,'/');
    if (!nextslash) error("insufficient slashes in PATH_INFO beyond directory");
    if (nextslash[1]=='.' || nextslash[1]=='#' || !nextslash[1]) error("bad char begin");
    if (nextslash-pathi > MAX_SCRIPTPATH_LEN) error("PATH_INFO script dir too long");
    scriptpathlen= scriptdirlen+(nextslash-pathi);
    scriptpath= xrealloc(scriptpath,scriptpathlen);
    memcpy(scriptpath,pathi,scriptpathlen); scriptpath[scriptpathlen]= 0;
    if (scriptpath[scriptpathlen-1]=='~') error("bad char end");
    r= stat(scriptpath,&stab); if (r) syserror("stat script");
    if (S_ISREG(stab.st_mode)) break;
    if (!S_ISDIR(stab.st_mode)) syserror("script not directory or file");
    lastlash= nextslash;
  }
  if (setenv("PATH_INFO",nextslash,1)) syserror("setenv PATH_INFO");

  arguments= xmalloc(sizeof(const char*)*(argc+5));
  nargs= 0;
  
  arguments[nargs++]= scriptpath;
  while ((av= (*++argv))) arguments[nargs++]= av;
  arguments[nargs++]= 0;

  execvp(scriptpath,(char*const*)arguments);
  syserror("exec script");
  return -1;
}