release/src-rt-6.x.4708/router/busybox/libbb/verror_msg.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9 #include "libbb.h"
  10 #if ENABLE_FEATURE_SYSLOG
  11 # include <syslog.h>
  12 #endif
  13
  14 #if ENABLE_FEATURE_SYSLOG
  15 smallint syslog_level = LOG_ERR;
  16 #endif
  17 smallint logmode = LOGMODE_STDIO;
  18 const char *msg_eol = "\n";
  19
  20 void FAST_FUNC bb_verror_msg(const char *s, va_list p, const char* strerr)
  21 {
  22         char *msg, *msg1;
  23         int applet_len, strerr_len, msgeol_len, used;
  24
  25         if (!logmode)
  26                 return;
  27
  28         if (!s) /* nomsg[_and_die] uses NULL fmt */
  29                 s = ""; /* some libc don't like printf(NULL) */
  30
  31         used = vasprintf(&msg, s, p);
  32         if (used < 0)
  33                 return;
  34
  35         /* This is ugly and costs +60 bytes compared to multiple
  36          * fprintf's, but is guaranteed to do a single write.
  37          * This is needed for e.g. httpd logging, when multiple
  38          * children can produce log messages simultaneously. */
  39
  40         applet_len = strlen(applet_name) + 2; /* "applet: " */
  41         strerr_len = strerr ? strlen(strerr) : 0;
  42         msgeol_len = strlen(msg_eol);
  43         /* can't use xrealloc: it calls error_msg on failure,
  44          * that may result in a recursion */
  45         /* +3 is for ": " before strerr and for terminating NUL */
  46         msg1 = realloc(msg, applet_len + used + strerr_len + msgeol_len + 3);
  47         if (!msg1) {
  48                 msg[used++] = '\n'; /* overwrites NUL */
  49                 applet_len = 0;
  50         } else {
  51                 msg = msg1;
  52                 /* TODO: maybe use writev instead of memmoving? Need full_writev? */
  53                 memmove(msg + applet_len, msg, used);
  54                 used += applet_len;
  55                 strcpy(msg, applet_name);
  56                 msg[applet_len - 2] = ':';
  57                 msg[applet_len - 1] = ' ';
  58                 if (strerr) {
  59                         if (s[0]) { /* not perror_nomsg? */
  60                                 msg[used++] = ':';
  61                                 msg[used++] = ' ';
  62                         }
  63                         strcpy(&msg[used], strerr);
  64                         used += strerr_len;
  65                 }
  66                 strcpy(&msg[used], msg_eol);
  67                 used += msgeol_len;
  68         }
  69
  70         if (logmode & LOGMODE_STDIO) {
  71                 fflush_all();
  72                 full_write(STDERR_FILENO, msg, used);
  73         }
  74 #if ENABLE_FEATURE_SYSLOG
  75         if (logmode & LOGMODE_SYSLOG) {
  76                 syslog(syslog_level, "%s", msg + applet_len);
  77         }
  78 #endif
  79         free(msg);
  80 }
  81
  82 #ifdef VERSION_WITH_WRITEV
  83 /* Code size is approximately the same, but currently it's the only user
  84  * of writev in entire bbox. __libc_writev in uclibc is ~50 bytes. */
  85 void FAST_FUNC bb_verror_msg(const char *s, va_list p, const char* strerr)
  86 {
  87         int strerr_len, msgeol_len;
  88         struct iovec iov[3];
  89
  90 #define used   (iov[2].iov_len)
  91 #define msgv   (iov[2].iov_base)
  92 #define msgc   ((char*)(iov[2].iov_base))
  93 #define msgptr (&(iov[2].iov_base))
  94
  95         if (!logmode)
  96                 return;
  97
  98         if (!s) /* nomsg[_and_die] uses NULL fmt */
  99                 s = ""; /* some libc don't like printf(NULL) */
 100
 101         /* Prevent "derefing type-punned ptr will break aliasing rules" */
 102         used = vasprintf((char**)(void*)msgptr, s, p);
 103         if (used < 0)
 104                 return;
 105
 106         /* This is ugly and costs +60 bytes compared to multiple
 107          * fprintf's, but is guaranteed to do a single write.
 108          * This is needed for e.g. httpd logging, when multiple
 109          * children can produce log messages simultaneously. */
 110
 111         strerr_len = strerr ? strlen(strerr) : 0;
 112         msgeol_len = strlen(msg_eol);
 113         /* +3 is for ": " before strerr and for terminating NUL */
 114         msgv = xrealloc(msgv, used + strerr_len + msgeol_len + 3);
 115         if (strerr) {
 116                 msgc[used++] = ':';
 117                 msgc[used++] = ' ';
 118                 strcpy(msgc + used, strerr);
 119                 used += strerr_len;
 120         }
 121         strcpy(msgc + used, msg_eol);
 122         used += msgeol_len;
 123
 124         if (logmode & LOGMODE_STDIO) {
 125                 iov[0].iov_base = (char*)applet_name;
 126                 iov[0].iov_len = strlen(applet_name);
 127                 iov[1].iov_base = (char*)": ";
 128                 iov[1].iov_len = 2;
 129                 /*iov[2].iov_base = msgc;*/
 130                 /*iov[2].iov_len = used;*/
 131                 fflush_all();
 132                 writev(STDERR_FILENO, iov, 3);
 133         }
 134 # if ENABLE_FEATURE_SYSLOG
 135         if (logmode & LOGMODE_SYSLOG) {
 136                 syslog(LOG_ERR, "%s", msgc);
 137         }
 138 # endif
 139         free(msgc);
 140 }
 141 #endif
 142
 143
 144 void FAST_FUNC bb_error_msg_and_die(const char *s, ...)
 145 {
 146         va_list p;
 147
 148         va_start(p, s);
 149         bb_verror_msg(s, p, NULL);
 150         va_end(p);
 151         xfunc_die();
 152 }
 153
 154 void FAST_FUNC bb_error_msg(const char *s, ...)
 155 {
 156         va_list p;
 157
 158         va_start(p, s);
 159         bb_verror_msg(s, p, NULL);
 160         va_end(p);
 161 }