subs.c

   1
   2 /*
   3  * SUBS.C
   4  *
   5  * Copyright 1994 Matthew Dillon (dillon@apollo.backplane.com)
   6  * Copyright 2009 James Pryor <profjim@jimpryor.net>
   7  * May be distributed under the GNU General Public License
   8  */
   9
  10 #include "defs.h"
  11
  12 Prototype void logn(int level, const char *ctl, ...);
  13 Prototype void logfd(int level, int fd, const char *ctl, ...);
  14 Prototype void fdprintf(int fd, const char *ctl, ...);
  15 Prototype int  ChangeUser(const char *user, short dochdir);
  16 Prototype void vlog(int level, int fd, const char *ctl, va_list va);
  17 Prototype void startlogger(void);
  18 Prototype void initsignals(void);
  19 Prototype char Hostname[64];
  20
  21 int slog(char *buf, const char *ctl, int nmax, va_list va, short useDate);
  22 char Hostname[64];
  23
  24
  25 void
  26 logn(int level, const char *ctl, ...)
  27 {
  28         va_list va;
  29
  30         va_start(va, ctl);
  31         vlog(level, 2, ctl, va);
  32         va_end(va);
  33 }
  34
  35 void
  36 logfd(int level, int fd, const char *ctl, ...)
  37 {
  38         va_list va;
  39
  40         va_start(va, ctl);
  41         vlog(level, fd, ctl, va);
  42         va_end(va);
  43 }
  44
  45 void
  46 fdprintf(int fd, const char *ctl, ...)
  47 {
  48         va_list va;
  49         char buf[2048];
  50
  51         va_start(va, ctl);
  52         vsnprintf(buf, sizeof(buf), ctl, va);
  53         write(fd, buf, strlen(buf));
  54         va_end(va);
  55 }
  56
  57 void
  58 vlog(int level, int fd, const char *ctl, va_list va)
  59 {
  60         char buf[2048];
  61         int  logfd;
  62     short n;
  63     static short useDate = 1;
  64
  65         if (level <= LogLevel) {
  66                 vsnprintf(buf,sizeof(buf), ctl, va);
  67                 if (ForegroundOpt == 1)
  68                         /* when -d or -f, we always (and only) log to stderr
  69                          * fd will be 2 except when 2 is bound to a execing subprocess, then it will be 8
  70                          */
  71                         write(fd, buf, strlen(buf));
  72                 else
  73                         if (LoggerOpt == 0) syslog(level, "%s", buf);
  74                         else {
  75                                 if ((logfd = open(LogFile,O_WRONLY|O_CREAT|O_APPEND,0600)) >= 0) {
  76                                         write(logfd, buf, n = slog(buf, ctl, sizeof(buf), va, useDate));
  77                                         useDate = (n && buf[n-1] == '\n');
  78                                         close(logfd);
  79                                 } else {
  80                                         int e = errno;
  81                                         fdprintf(fd, "failed to open logfile '%s' reason: %s\n",
  82                                                         LogFile,
  83                                                         strerror(e)
  84                                                         );
  85                                         exit(e);
  86                                 }
  87                         }
  88         }
  89 }
  90
  91 int
  92 slog(char *buf, const char *ctl, int nmax, va_list va, short useDate)
  93 {
  94     time_t t = time(NULL);
  95     struct tm *tp = localtime(&t);
  96     buf[0] = 0;
  97     if (useDate) {
  98                 char hdr[128];
  99                 hdr[0] = 0;
 100                 strftime(hdr, 128, LOG_DATE_FMT, tp);
 101                 if (!gethostname(Hostname, 63))
 102                         Hostname[63] = 0;  // if hostname is larger than buffer, gethostname() doesn't promise to null-terminate it
 103                 else
 104                         Hostname[0] = 0;   // gethostname() call failed
 105                 snprintf(buf, 194, hdr, Hostname);
 106         }
 107     vsnprintf(buf + strlen(buf), nmax, ctl, va);
 108     return(strlen(buf));
 109 }
 110
 111 int
 112 ChangeUser(const char *user, short dochdir)
 113 {
 114         struct passwd *pas;
 115
 116         /*
 117          * Obtain password entry and change privilages
 118          */
 119
 120         if ((pas = getpwnam(user)) == 0) {
 121                 logn(LOG_ERR, "failed to get uid for %s\n", user);
 122                 return(-1);
 123         }
 124         setenv("USER", pas->pw_name, 1);
 125         setenv("HOME", pas->pw_dir, 1);
 126         setenv("SHELL", "/bin/sh", 1);
 127
 128         /*
 129          * Change running state to the user in question
 130          */
 131
 132         if (initgroups(user, pas->pw_gid) < 0) {
 133                 logn(LOG_ERR, "initgroups failed: %s %s\n", user, strerror(errno));
 134                 return(-1);
 135         }
 136         if (setregid(pas->pw_gid, pas->pw_gid) < 0) {
 137                 logn(LOG_ERR, "setregid failed: %s %d\n", user, pas->pw_gid);
 138                 return(-1);
 139         }
 140         if (setreuid(pas->pw_uid, pas->pw_uid) < 0) {
 141                 logn(LOG_ERR, "setreuid failed: %s %d\n", user, pas->pw_uid);
 142                 return(-1);
 143         }
 144         if (dochdir) {
 145                 if (chdir(pas->pw_dir) < 0) {
 146                         logn(LOG_ERR, "chdir failed: %s %s\n", user, pas->pw_dir);
 147                         if (chdir(TempDir) < 0) {
 148                                 logn(LOG_ERR, "chdir failed: %s %s\n", user, TempDir);
 149                                 return(-1);
 150                         }
 151                 }
 152         }
 153         return(pas->pw_uid);
 154 }
 155
 156
 157 void
 158 startlogger (void) {
 159         int logfd;
 160
 161         if (LoggerOpt == 0)
 162                 openlog(LOG_IDENT, LOG_CONS|LOG_PID,LOG_CRON);
 163
 164         else { /* test logfile */
 165                 if ((logfd = open(LogFile,O_WRONLY|O_CREAT|O_APPEND,0600)) >= 0)
 166                         close(logfd);
 167                 else
 168                         errx(errno, "failed to open logfile '%s' reason: %s",
 169                                         LogFile,
 170                                         strerror(errno)
 171                                 );
 172         }
 173 }
 174
 175 void
 176 initsignals (void) {
 177         signal(SIGHUP,SIG_IGN); /* JP: hmm.. but, if kill -HUP original
 178                                                          * version - has died. ;(
 179                                                          */
 180 }