util_funcs.c

ucd-snmp源代码

/*
 * util_funcs.c
 */

#include <config.h>

#if HAVE_IO_H
#include <io.h>
#endif
#include <stdio.h>
#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if HAVE_MALLOC_H
#include <malloc.h>
#endif
#include <sys/types.h>
#ifdef __alpha
#ifndef _BSD
#define _BSD
#define _myBSD
#endif
#endif
#if HAVE_SYS_WAIT_H
# include <sys/wait.h>
#endif
#ifdef __alpha
#ifdef _myBSD
#undef _BSD
#undef _myBSD
#endif
#endif
#ifndef WEXITSTATUS
# define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
#endif
#ifndef WIFEXITED
# define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
#endif
#if TIME_WITH_SYS_TIME
# ifdef WIN32
#  include <sys/timeb.h>
# else
#  include <sys/time.h>
# endif
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <errno.h>
#include <signal.h>
#if HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#include <ctype.h>
#if HAVE_WINSOCK_H
#include <winsock.h>
#endif
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_BASETSD_H
#include <basetsd.h>
#define ssize_t SSIZE_T
#endif
#if HAVE_RAISE
#define alarm raise
#endif
#include "mibincl.h"
#include "struct.h"
#include "util_funcs.h"
#include "system.h"
#if HAVE_LIMITS_H
#include "limits.h"
#endif
#ifdef USING_UCD_SNMP_ERRORMIB_MODULE
#include "ucd-snmp/errormib.h"
#else
#define setPerrorstatus(x) snmp_log_perror(x)
#endif
#include "read_config.h"

#ifdef EXCACHETIME
static long cachetime;
#endif

extern int numprocs, numextens;

void
Exit(int var)
{
  snmp_log(LOG_ERR, "Server Exiting with code %d\n",var);
  exit(var);
}

static const char *
make_tempfile(void)
{
  static char	name[32];
  int		fd = -1;

  strcpy(name, "/tmp/snmpdXXXXXX");
#ifdef HAVE_MKSTEMP
  fd = mkstemp(name);
#else
  if (mktemp(name))
    fd = open(name, O_CREAT|O_EXCL|O_WRONLY);
#endif
  if (fd >= 0) {
    close(fd);
    return name;
  }
  return NULL;
}

int shell_command(struct extensible *ex)
{
#if HAVE_SYSTEM
  const char *ofname;
  char shellline[STRMAX];
  FILE *shellout;
  
  ofname = make_tempfile();
  if (ofname == NULL) {
    ex->output[0] = 0;
    ex->result = 127;
    return ex->result;
  }

  sprintf(shellline,"%s > %s",ex->command, ofname);
  ex->result = system(shellline);
  ex->result = WEXITSTATUS(ex->result);
  shellout = fopen(ofname,"r");
  if(shellout != NULL) {
    if (fgets(ex->output,sizeof(ex->output),shellout) == NULL) {
      ex->output[0] = 0;
    }
    fclose(shellout);
  }
  unlink(ofname);
#else
  ex->output[0] = 0;
  ex->result = 0;
#endif
  return(ex->result);
}

#define MAXOUTPUT 300

int exec_command(struct extensible *ex)
{
#if HAVE_EXECV
  int fd;
  FILE *file;
  
  if ((fd = get_exec_output(ex))) {
    file = fdopen(fd,"r");
    if (fgets(ex->output,sizeof(ex->output),file) == NULL) {
      ex->output[0] = 0;
    }
    fclose(file);
    wait_on_exec(ex);
  } else
#endif
  {
    ex->output[0] = 0;
    ex->result = 0;
  }
  return(ex->result);
}

void wait_on_exec(struct extensible *ex)
{
#ifndef EXCACHETIME
    if (ex->pid && waitpid(ex->pid,&ex->result,0) < 0) {
      setPerrorstatus("waitpid");
    }
    ex->pid = 0;
#endif
}

#define MAXARGS 30

int get_exec_output(struct extensible *ex)
{
#if HAVE_EXECV
  int fd[2],i, cnt;
  char ctmp[STRMAX], *cptr1, *cptr2, argvs[STRMAX], **argv, **aptr;
#ifdef EXCACHETIME
  char cachefile[STRMAX];
  char cache[MAXCACHESIZE];
  ssize_t cachebytes;
  long curtime;
  static char lastcmd[STRMAX];
  int cfd;
  static int lastresult;
  int readcount;
#endif

#ifdef EXCACHETIME
  sprintf(cachefile, "%s/%s", PERSISTENT_DIRECTORY,CACHEFILE);
  curtime = time(NULL);
  if (curtime > (cachetime + EXCACHETIME) ||
      strcmp(ex->command, lastcmd) != 0) {
    strcpy(lastcmd,ex->command);
    cachetime = curtime;
#endif
    if (pipe(fd)) 
      {
        setPerrorstatus("pipe");
#ifdef EXCACHETIME
        cachetime = 0;
#endif
        return 0;
      }
    if ((ex->pid = fork()) == 0) 
      {
        close(1);
        if (dup(fd[1]) != 1)
          {
            setPerrorstatus("dup");
            return 0;
          }

        /* write standard output and standard error to pipe. */
        /* close all other file descriptors. */
        for (cnt=getdtablesize()-1; cnt>=2; --cnt)
                (void) close(cnt);
        (void) dup(1);                 /* stderr */

        /* set standard input to /dev/null */
        close(0);
        (void) open("/dev/null", O_RDWR);

        for(cnt=1,cptr1 = ex->command, cptr2 = argvs; cptr1 && *cptr1 != 0;
            cptr2++, cptr1++) {
          *cptr2 = *cptr1;
          if (*cptr1 == ' ') {
            *(cptr2++) = 0;
            if ((cptr1 = skip_white(cptr1)) == NULL)
                break;
            if (cptr1) {
                *cptr2 = *cptr1;
                if (*cptr1 != 0) cnt++;
            }
          }
        }
        *cptr2 = 0;
        *(cptr2+1) = 0;
        argv = (char **) malloc((cnt+2) * sizeof(char *));
        if (argv == NULL)
          return 0; /* memory alloc error */
        aptr = argv;
        *(aptr++) = argvs;
        for (cptr2 = argvs, i=1; i != cnt; cptr2++)
          if (*cptr2 == 0) {
            *(aptr++) = cptr2 + 1;
            i++;
          }
        while (*cptr2 != 0) cptr2++;
        *(aptr++) = NULL;
        copy_word(ex->command,ctmp);
        execv(ctmp,argv);
        perror(ctmp);
        exit(1);
      }
    else
      {
        close(fd[1]);
        if (ex->pid < 0) {
          close(fd[0]);
          setPerrorstatus("fork");
#ifdef EXCACHETIME
          cachetime = 0;
#endif
          return 0;
        }
#ifdef EXCACHETIME
        unlink(cachefile);
	/* XXX  Use SNMP_FILEMODE_CLOSED instead of 644? */
        if ((cfd = open(cachefile,O_WRONLY|O_TRUNC|O_CREAT,0644)) < 0) {
          setPerrorstatus(cachefile);
          cachetime = 0;
          return 0;
        }
        fcntl(fd[0],F_SETFL,O_NONBLOCK);  /* don't block on reads */
#ifdef HAVE_USLEEP
        for (readcount = 0; readcount <= MAXREADCOUNT*100 &&
               (cachebytes = read(fd[0],(void *)cache,MAXCACHESIZE));
             readcount++) {
#else
        for (readcount = 0; readcount <= MAXREADCOUNT &&
               (cachebytes = read(fd[0],(void *)cache,MAXCACHESIZE));
             readcount++) {
#endif
          if (cachebytes > 0)
            write(cfd,(void *) cache, cachebytes);
          else if (cachebytes == -1 && errno != EAGAIN) {
            setPerrorstatus("read");
            break;
          }
          else
#ifdef HAVE_USLEEP
            usleep (10000);	/* sleeps for 0.01 sec */
#else
	    sleep (1);
#endif
        }
        close(cfd);
        close(fd[0]);
        /* wait for the child to finish */
        if (ex->pid > 0 && waitpid(ex->pid,&ex->result,0) < 0) {
          setPerrorstatus("waitpid()");
          cachetime = 0;
          return 0;
        }
        ex->pid = 0;
        ex->result = WEXITSTATUS(ex->result);
        lastresult = ex->result;
#else /* !EXCACHETIME */
        return(fd[0]);
#endif
      }
#ifdef EXCACHETIME
  }
  else {
      ex->result = lastresult;
  }
  if ((cfd = open(cachefile,O_RDONLY)) < 0) {
    setPerrorstatus(cachefile);
    return 0;
  }
  return(cfd);
#endif

#else /* !HAVE_EXECV */
  return 0;
#endif
}

int get_exec_pipes(char *cmd,
		   int *fdIn, 
		   int *fdOut, 
		   int *pid)

{
#if HAVE_EXECV
  int fd[2][2],i, cnt;
  char ctmp[STRMAX], *cptr1, *cptr2, argvs[STRMAX], **argv, **aptr;
  /* Setup our pipes */
  if (pipe(fd[0]) || pipe(fd[1]))
    {
      setPerrorstatus("pipe");
      return 0;
    }
  if ((*pid = fork()) == 0)   /* First handle for the child */
    {
      close(0);
      if (dup(fd[0][0]) != 0)
        {
          setPerrorstatus("dup 0");
          return 0;
        }
      close(1);
      if (dup(fd[1][1]) != 1)
        {
          setPerrorstatus("dup 1");
          return 0;
        }

        /* write standard output and standard error to pipe. */
        /* close all non-standard open file descriptors */
        for (cnt=getdtablesize()-1; cnt>=2; --cnt)
                (void) close(cnt);
        (void) dup(1);                 /* stderr */

      for(cnt=1,cptr1 = cmd, cptr2 = argvs; *cptr1 != 0;
          cptr2++, cptr1++) {
        *cptr2 = *cptr1;
        if (*cptr1 == ' ') {
          *(cptr2++) = 0;
          if ((cptr1 = skip_white(cptr1)) == NULL)
              break;
          *cptr2 = *cptr1;
          if (*cptr1 != 0) cnt++;
        }
      }
      *cptr2 = 0;
      *(cptr2+1) = 0;
      argv = (char **) malloc((cnt+2) * sizeof(char *));
      if (argv == NULL)
        return 0; /* memory alloc error */
      aptr = argv;
      *(aptr++) = argvs;
      for (cptr2 = argvs, i=1; i != cnt; cptr2++)
        if (*cptr2 == 0) {
          *(aptr++) = cptr2 + 1;
          i++;
        }
      while (*cptr2 != 0) cptr2++;
      *(aptr++) = NULL;
      copy_word(cmd,ctmp);
      execv(ctmp,argv);
      perror(ctmp);
      exit(1);
    }
  else
    {
      close(fd[0][0]);
      close(fd[1][1]);
      if (*pid < 0) {
        close(fd[0][1]);
        close(fd[1][0]);
        setPerrorstatus("fork");
        return 0;
      }
      *fdIn = fd[1][0];
      *fdOut = fd[0][1];
      return(1); /* We are returning 0 for error... */
    }
#endif /* !HAVE_EXECV */
  return 0;
}

int clear_cache(int action,
		u_char *var_val,
		u_char var_val_type,
		size_t var_val_len,
		u_char *statP,
		oid *name,
		size_t name_len)
{
  
  long tmp=0;

  if (var_val_type != ASN_INTEGER) {
    snmp_log(LOG_NOTICE, "Wrong type != int\n");
    return SNMP_ERR_WRONGTYPE;
  }
  tmp = *((long *) var_val);
  if (tmp == 1 && action == COMMIT) {
#ifdef EXCACHETIME
    cachetime = 0;                      /* reset the cache next read */
#endif 
  } 
  return SNMP_ERR_NOERROR;
}

char **argvrestartp, *argvrestartname, *argvrestart;

RETSIGTYPE restart_doit(int a)
{
    snmp_shutdown("snmpd");

  /* do the exec */
#if HAVE_EXECV
  execv(argvrestartname,argvrestartp);
  setPerrorstatus(argvrestartname);
#endif
}

int
restart_hook(int action,
	     u_char *var_val,
	     u_char var_val_type,
	     size_t var_val_len,
	     u_char *statP,
	     oid *name,