ezmlm-cron.c

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#include <sys/types.h>
#include <sys/stat.h>
#include <pwd.h>
#include <unistd.h>
#include "stralloc.h"
#include "getoptb.h"
#include "buffer.h"
#include "error.h"
#include "str.h"
#include "fmt.h"
#include "wait.h"
#include "readwrite.h"
#include "sig.h"
#include "case.h"
#include "scan.h"
#include "open.h"
#include "lock.h"
#include "byte.h"
#include "getln.h"
#include "auto_qmail.h"
#include "auto_cron.h"
#include "auto_version.h"
#include "errtxt.h"
#include "idx.h"
#include "wrap.h"
#include "logmsg.h"
#include "lockfile.h"
 
#define WHO "ezmlm-cron"
 
static void die_usage() { logmsg(WHO,100,USAGE,"ezmlm-cron [-cCdDlLvV] [-w dow] [-t hh:mm] [-i hrs] listadr code"); }
static void die_dow() { logmsg(WHO,100,FATAL,ERR_DOW); }
static void die_nomem() { logmsg(WHO,111,FATAL,ERR_NOMEM); }
 
unsigned long deltah = 24L;       /* default interval 24h */
unsigned long hh = 4L;                /* default time 04:12 */
unsigned long mm = 12L;
const char *dow = "*";               /* day of week */
const char *qmail_inject = "/bin/qmail-inject ";
char strnum[FMT_ULONG];
unsigned long uid,euid;
 
stralloc line = {0};
stralloc rp = {0};
stralloc addr = {0};
stralloc user = {0};
stralloc euser = {0};
stralloc dir = {0};
stralloc listaddr = {0};
 
struct passwd *ppasswd;
 
int opt, match;
int hostmatch;
int localmatch;
unsigned long dh,t;
int founduser = 0;
int listmatch = 0;
int flagconfig = 0;
int flagdelete = 0;
int flaglist = 0;
int flagdigit = 0;
int flagours;
int foundlocal;
int foundmatch = 0;
int nolists = 0;
unsigned long maxlists;
unsigned int pos, pos2, poslocal, len;
unsigned int lenhost, lenlocal;
unsigned int part0start, part0len;
int fdlock, fdin, fdout;
 
char *local = (char *) 0;  /* list = local@host */
const char *host = (char *) 0;
const char *code = (char *) 0;      /* digest code */
const char *cp;
 
void die_syntax()
{
  if (!stralloc_0(&line)) die_nomem();
  logmsg(WHO,100,FATAL,B(TXT_EZCRONRC ERR_SYNTAX,line.s));
}
 
void die_argument() { logmsg(WHO,100,FATAL,ERR_NOT_CLEAN); }

 
int isclean(char *addr,int flagaddr)
{
  unsigned int pos;
  char ch;
  char *cp;
 
  if (flagaddr) {                                  /* shoud have one '@' */
    pos = str_chr(addr,'@');
    if (!pos || !addr[pos])
      return 0;                                    /* at least 1 char for local */
    if (!addr[pos+1])
      return 0;                                    /* host must be at least 1 char */
    pos++;
    case_lowerb(addr+pos,str_len(addr)-pos);
  } else
    pos = 0;
 
  pos +=  str_chr(addr + pos,'@');
  if (addr[pos])                               /* but no more */
    return 0;
  cp = addr;
 
  while ((ch = *(cp++)))
    if (!(ch >= 'a' && ch <= 'z') &&
        !(ch >= 'A' && ch <= 'Z') &&
        !(ch >= '0' && ch <= '9') &&
        ch != '.' && ch != '-' && ch != '_' && ch != '@')
      return 0;
  return 1;
}
 
char inbuf[512];
buffer bi;
char outbuf[512];
buffer bo;
 
int main(int argc,char **argv)
{
  int child;
  const char *sendargs[4];
 
  umask(077);
  sig_pipeignore();
 
  while ((opt = getoptb(argc,argv,"cCdDi:lLt:w:vV")) != opteof)
    switch (opt) {
      case 'c': flagconfig = 1; break;
      case 'C': flagconfig = 0; break;
      case 'd': flagdelete = 1; break;
      case 'D': flagdelete = 0; break;
      case 'i': scan_ulong(optarg,&deltah); break;
      case 'l': flaglist = 1; break;
      case 'L': flaglist = 0; break;
      case 't': pos = scan_ulong(optarg,&hh);
                if (!optarg[pos++] == ':') die_usage();
                pos = scan_ulong(optarg + pos,&mm);
                break;
      case 'w': dow = optarg;
                cp = optarg - 1;
                while (*(++cp)) {
                  if (*cp >= '0' && *cp <= '7') {
                    if (flagdigit) die_dow();
                    flagdigit = 1;
                  } else if (*cp == ',') {
                    if (!flagdigit) die_dow();
                    flagdigit = 0;
                  } else
                    die_dow();
                }
                break;
      case 'v':
      case 'V': logmsg(WHO,0,VERSION,auto_version); 
      default:  die_usage();
    }
  if (flaglist + flagdelete + flagconfig > 1)
    logmsg(WHO,100,FATAL,ERR_EXCLUSIVE);
  uid = getuid();
  if (uid && !(euid = geteuid()))
    logmsg(WHO,100,FATAL,ERR_SUID);
  if (!(ppasswd = getpwuid(uid)))
    logmsg(WHO,100,FATAL,ERR_UID);
  if (!stralloc_copys(&user,ppasswd->pw_name)) die_nomem();
  if (!stralloc_0(&user)) die_nomem();
  if (!(ppasswd = getpwuid(euid)))
    logmsg(WHO,100,FATAL,ERR_EUID);
  if (!stralloc_copys(&dir,ppasswd->pw_dir)) die_nomem();
  if (!stralloc_0(&dir)) die_nomem();
  if (!stralloc_copys(&euser,ppasswd->pw_name)) die_nomem();
  if (!stralloc_0(&euser)) die_nomem();
 
  if (chdir(dir.s) == -1)
    logmsg(WHO,111,FATAL,B(ERR_SWITCH,dir.s));
 
  local = argv[optind++];               /* list address, optional for -c & -l */
  if (!local) {
    if (!flagconfig && !flaglist) die_usage();
    lenlocal = 0;
    lenhost = 0;
  } else {
    if (!stralloc_copys(&listaddr,local)) die_nomem();
    if (!isclean(local,1)) die_argument();
    pos = str_chr(local,'@');
    lenlocal = pos;
    local[pos] = '\0';
    host = local + pos + 1;
    lenhost = str_len(host);
    code = argv[optind];
    if (!code) {                               /* ignored for -l, -c, and -d */
      if (flagdelete || flaglist || flagconfig)
                                                               /* get away with not putting code for delete */
        code = "a";                    /* a hack - so what! */
      else
        die_usage();
    } else
      if (!isclean(code,0))
        die_argument();
  }
  if ((fdin = open_read(TXT_EZCRONRC)) == -1)
    logmsg(WHO,111,FATAL,B(ERR_OPEN,dir.s,"/","TXT_EZCRONRC"));
        /* first line is special */
  buffer_init(&bi,buffer_unixread,fdin,inbuf,sizeof(inbuf));
  if (getln(&bi,&line,&match,'\n') == -1)
    logmsg(WHO,111,FATAL,B(ERR_OPEN,dir.s,"/","TXT_EZCRONRC"));
 
  if (!match)
    logmsg(WHO,111,FATAL,B(ERR_OPEN,dir.s,"/","TXT_EZCRONRC"));
        /* (since we have match line.len has to be >= 1) */
  line.s[line.len - 1] = '\0';
  if (!isclean(line.s,0))         /* host for bounces */
    logmsg(WHO,100,INFO,B(ERR_CFHOST,dir.s,"/","TXT_EZCRONRC"));
  if (!stralloc_copys(&rp,line.s)) die_nomem();
 
  match = 1;
  for(;;) {
    if (!match) break;             /* to allow last line without '\n' */
    if (getln(&bi,&line,&match,'\n') == -1)
      logmsg(WHO,111,FATAL,B(ERR_READ,dir.s,"/","TXT_EZCRONRC"));
    if (!line.len)
      break;
    line.s[line.len-1] = '\0';
    if (!case_startb(line.s,line.len,user.s))
      continue;
    pos = user.len - 1;
    if (pos >= line.len || line.s[pos] != ':')
      continue;
    founduser = 1;              /* got user line */
    break;
  }
  close(fdin);
  if (!founduser)
    logmsg(WHO,100,FATAL,ERR_BADUSER);
  
  if (flagconfig) {
    line.s[line.len-1] = '\n';          /* not very elegant ;-) */
    buffer_init(&bo,buffer_unixwrite,1,outbuf,sizeof(outbuf));
    if (buffer_put(&bo,line.s,line.len) == -1)
      logmsg(WHO,111,FATAL,B(ERR_WRITE,"stdout"));
    if (buffer_flush(&bo) == -1)
      logmsg(WHO,111,FATAL,B(ERR_WRITE,"stdout"));
    _exit(0);
  }
  ++pos;                                                       /* points to first ':' */
  len = str_chr(line.s+pos,':');          /* second ':' */
    if (!line.s[pos + len])
      die_syntax();
  if (!local) {                                             /* only -d and std left */
    localmatch = 1;
    hostmatch = 1;
  } else {
    hostmatch = 0;
    if (len <= str_len(local))
      if (!str_diffn(line.s+pos,local,len))
        localmatch = 1;
  }
  pos += len + 1;
  len = str_chr(line.s + pos,':');      /* third */
  if (!line.s[pos + len])
    die_syntax();
  if (local) {                                              /* check host */
    if (len == 0)                                     /* empty host => any host */
      hostmatch = 1;
    else
      if (len == str_len(host))
        if (!case_diffb(line.s+pos,len,host))
          hostmatch = 1;
  }
  pos += len + 1;
  pos += scan_ulong(line.s+pos,&maxlists);
  if (line.s[pos]) {                                 /* check additional lists */
    if (line.s[pos] != ':')
      die_syntax();
    if (line.s[pos+1+str_chr(line.s+pos+1,':')])
      die_syntax();                      /* reminder lists are not separated by ':'  */
                                                         /* otherwise a ':' or arg miscount will die silently */
    if (local) {
      while (++pos < line.len) {
        len = str_chr(line.s + pos,'@');
        if (len == lenlocal && !str_diffn(line.s + pos,local,len)) {
          pos += len;
          if (!line.s[pos]) break;
          pos++;
          len = str_chr(line.s+pos,',');
            if (len == lenhost && !case_diffb(line.s+pos,len,host)) {
              listmatch = 1;
              break;
            }
        }
        pos += len;
      }
    }
  }
  if (!listmatch) {
    if (!hostmatch)
      logmsg(WHO,100,FATAL,ERR_BADHOST);
    if (!localmatch)
      logmsg(WHO,100,FATAL,ERR_BADLOCAL);
  }
                                             /* assemble correct line */
  if (!flaglist) {
    if (!stralloc_copyb(&addr,strnum,fmt_ulong(strnum,mm))) die_nomem();
    if (!stralloc_cats(&addr," ")) die_nomem();
    dh = 0L;
    if (deltah <= 3L) dh = deltah;
    else if (deltah <= 6L) dh = 6L;
    else if (deltah <= 12L) dh = 12L;
    else if (deltah <= 24L) dh = 24L;
    else if (deltah <= 48L) {
      if (dow[0] == '*') dow = "1,3,5";
    } else if (deltah <= 72L) {
      if (dow[0] == '*') dow = "1,4";
    } else
    if (dow[0] == '*') dow = "1";
 
    if (!dh) {
      if (!stralloc_cats(&addr,"*")) die_nomem();
    } else {
      if (!stralloc_catb(&addr,strnum,fmt_ulong(strnum,hh))) die_nomem();
      for (t = hh + dh; t < hh + 24L; t+=dh) {
        if (!stralloc_cats(&addr,",")) die_nomem();
        if (!stralloc_catb(&addr,strnum,fmt_ulong(strnum,t % 24L))) die_nomem();
      }
    }
    if (!stralloc_cats(&addr," * * ")) die_nomem();
    if (!stralloc_cats(&addr,dow)) die_nomem();
    if (!stralloc_cats(&addr," ")) die_nomem();
    part0start = addr.len;                           /* /var/qmail/bin/qmail-inject */
    if (!stralloc_cats(&addr,auto_qmail)) die_nomem();
    if (!stralloc_cats(&addr,qmail_inject)) die_nomem();
    part0len = addr.len - part0start;
    if (!stralloc_cats(&addr,local)) die_nomem();
    if (!stralloc_cats(&addr,"-dig-")) die_nomem();
    if (!stralloc_cats(&addr,code)) die_nomem();
    if (!stralloc_cats(&addr,"@")) die_nomem();
    if (!stralloc_cats(&addr,host)) die_nomem();
                /* feed 'Return-Path: <user@host>' to qmail-inject */
    if (!stralloc_cats(&addr,"%Return-path: <")) die_nomem();
    if (!stralloc_cats(&addr,user.s)) die_nomem();
    if (!stralloc_cats(&addr,"@")) die_nomem();
    if (!stralloc_cat(&addr,&rp)) die_nomem();
    if (!stralloc_cats(&addr,">\n")) die_nomem();
  }
  if (!stralloc_0(&addr)) die_nomem();
 
  if (!flaglist) {
        /* now to rewrite crontab we need to lock */
    fdlock = lockfile("crontabl");
  }                                    /* if !flaglist */
  if ((fdin = open_read("crontab")) == -1) {
    if (errno != ENOENT)
      logmsg(WHO,111,FATAL,B(ERR_READ,dir.s,"/crontab"));
  } else
    buffer_init(&bi,buffer_unixread,fdin,inbuf,sizeof(inbuf));
  if (flaglist)
    buffer_init(&bo,buffer_unixwrite,1,outbuf,sizeof(outbuf));
  else {
    if ((fdout = open_trunc("crontabn")) == -1)
      logmsg(WHO,111,FATAL,B(ERR_WRITE,dir.s,"/crontabn "));
    buffer_init(&bo,buffer_unixwrite,fdout,outbuf,sizeof(outbuf));
  }
  line.len = 0;
 
  if (fdin != -1) {
    for (;;) {
      if (!flaglist && line.len) {
        line.s[line.len-1] = '\n';
        if (buffer_put(&bo,line.s,line.len) == -1)
          logmsg(WHO,111,FATAL,B(ERR_WRITE,dir.s,"/crontabn"));
      }
      if (getln(&bi,&line,&match,'\n') == -1)
        logmsg(WHO,111,FATAL,B(ERR_READ,dir.s,"/crontab"));
      if (!match)
        break;
      flagours = 0;                                     /* assume entry is not ours */
      foundlocal = 0;
      line.s[line.len - 1] = '\0';          /* match so at least 1 char */
      pos = 0;
      while (line.s[pos] == ' ' && line.s[pos] == '\t') ++pos;
      if (line.s[pos] == '#')
        continue;                                        /* cron comment */
      pos = str_chr(line.s,'/');
      if (!str_start(line.s+pos,auto_qmail)) continue;
      pos += str_len(auto_qmail);
      if (!str_start(line.s+pos,qmail_inject)) continue;
      pos += str_len(qmail_inject);
      poslocal = pos;
      pos = byte_rchr(line.s,line.len,'<');     /* should be Return-Path: < */
      if (pos == line.len)
        continue;                                        /* not ezmlm-cron line */
      pos++;
     len = str_chr(line.s+pos,'@');
      if (len == user.len - 1 && !str_diffn(line.s+pos,user.s,len)) {
        flagours = 1;
        ++nolists;                                /* belongs to this user */
      }
      if (!local) {
        foundlocal = 1;
      } else {
        pos = poslocal + str_chr(line.s+poslocal,'@');
        if (pos + lenhost +1 >= line.len) continue;
        if (case_diffb(line.s+pos+1,lenhost,host)) continue;
        if (line.s[pos+lenhost+1] != '%') continue;
                                /* check local */
        if (poslocal + lenlocal + 5 >= line.len) continue;
        if (!str_start(line.s+poslocal,local)) continue;
        pos2 = poslocal+lenlocal;
        if (!str_start(line.s+pos2,"-dig-")) continue;
        foundlocal = 1;
      }
      if (foundlocal) {
        foundmatch = 1;
        if (flaglist && (local || flagours)) {
          if (buffer_put(&bo,line.s,line.len) == -1)
            logmsg(WHO,111,FATAL,B(ERR_WRITE,"stdout"));
          if (buffer_put(&bo,"\n",1) == -1)
            logmsg(WHO,111,FATAL,B(ERR_WRITE,"stdout"));
        }
        line.len = 0;           /* same - kill line */
        if (flagours)
          --nolists;
      }
    }
    close(fdin);
  }
  if (flaglist) {
    if (buffer_flush(&bo) == -1)
      logmsg(WHO,111,FATAL,B(ERR_FLUSH,"stdout"));
    if (foundmatch)           /* means we had a match */
      _exit(0);
    else
      logmsg(WHO,100,FATAL,ERR_NO_MATCH);
  }
        /* only -d and regular use left */
 
  if (nolists >= maxlists && !flagdelete)
    logmsg(WHO,100,FATAL,ERR_LISTNO);
  if (!flagdelete)
    if (buffer_put(&bo,addr.s,addr.len-1) == -1)
      logmsg(WHO,111,FATAL,B(ERR_WRITE,dir.s,"/crontabn"));
  if (flagdelete && !foundlocal)
    logmsg(WHO,100,FATAL,ERR_NO_MATCH);
  if (buffer_flush(&bo) == -1)
    logmsg(WHO,111,FATAL,B(ERR_FLUSH,dir.s,"/crontabn"));
  if (fsync(fdout) == -1)
    logmsg(WHO,111,FATAL,B(ERR_SYNC,dir.s,"/crontabn"));
  if (close(fdout) == -1)
    logmsg(WHO,111,FATAL,B(ERR_CLOSE,dir.s,"/crontabn"));
  if (rename("crontabn","crontab") == -1)
    logmsg(WHO,111,FATAL,B(ERR_MOVE,dir.s,"/crontabn"));
  sendargs[0] = "sh";
  sendargs[1] = "-c";
 
  if (!stralloc_copys(&line,auto_cron)) die_nomem();
  if (!stralloc_cats(&line,"/crontab '")) die_nomem();
  if (!stralloc_cats(&line,dir.s)) die_nomem();
  if (!stralloc_cats(&line,"/crontab'")) die_nomem();
  if (!stralloc_0(&line)) die_nomem();
  sendargs[2] = line.s;
  sendargs[3] = 0;
  if ((child = wrap_fork()) == 0) {
    if (setreuid(euid,euid) == -1)
      logmsg(WHO,100,FATAL,ERR_SETUID);
    wrap_execvp(sendargs);
  }
  /* parent */
  switch (wrap_waitpid(child)) {
      case 0:  _exit(0);
      default: logmsg(WHO,111,FATAL,ERR_CRONTAB);
  }
  
  return 0;
}