Commit c3d1b07c authored by Yang Tse's avatar Yang Tse
Browse files

ensure that errno is not modified inside Curl_strerror()

parent 77bafd82

lib/strerror.c

+39 −33
Original line number Diff line number Diff line
@@ -24,10 +24,11 @@ 
#include "setup.h"



#ifdef HAVE_STRERROR_R

#if !defined(HAVE_POSIX_STRERROR_R) && !defined(HAVE_GLIBC_STRERROR_R)

#error "you MUST have either POSIX or glibc strerror_r if strerror_r is found"

#endif /* !POSIX && !glibc */

#endif /* HAVE_STRERROR_R */

#  if (!defined(HAVE_POSIX_STRERROR_R) && !defined(HAVE_GLIBC_STRERROR_R)) || \

       (defined(HAVE_POSIX_STRERROR_R) &&  defined(HAVE_GLIBC_STRERROR_R))

#    error "strerror_r MUST be either POSIX-style or glibc-style"

#  endif

#endif



#include <curl/curl.h>

#include <stdlib.h>
@@ -43,14 +44,6 @@ 
#define _MPRINTF_REPLACE /* use our functions only */

#include <curl/mprintf.h>



#if defined(HAVE_STRERROR_R) && defined(HAVE_NO_STRERROR_R_DECL)

#ifdef HAVE_POSIX_STRERROR_R

/* seen on AIX 5100-02 gcc 2.9 */

extern int strerror_r(int errnum, char *strerrbuf, size_t buflen);

#else

extern char *strerror_r(int errnum, char *buf, size_t buflen);

#endif

#endif



const char *

curl_easy_strerror(CURLcode error)
@@ -590,6 +583,7 @@ const char *Curl_strerror(struct connectdata *conn, int err) 
{

  char *buf, *p;

  size_t max;

  int old_errno = ERRNO;



  DEBUGASSERT(conn);

  DEBUGASSERT(err >= 0);
@@ -601,17 +595,15 @@ const char *Curl_strerror(struct connectdata *conn, int err) 
#ifdef USE_WINSOCK



#ifdef _WIN32_WCE

  buf[0]=0;

  {

    wchar_t wbuf[256];

    wbuf[0] = L'\0';



    FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, err,

                  LANG_NEUTRAL, wbuf, sizeof(wbuf)/sizeof(wchar_t), NULL);

    wcstombs(buf,wbuf,max);

  }



#else



  /* 'sys_nerr' is the maximum errno number, it is not widely portable */

  if(err >= 0 && err < sys_nerr)

    strncpy(buf, strerror(err), max);
@@ -622,34 +614,43 @@ const char *Curl_strerror(struct connectdata *conn, int err) 
      snprintf(buf, max, "Unknown error %d (%#x)", err, err);

  }

#endif



#else /* not USE_WINSOCK coming up */



  /* These should be atomic and hopefully thread-safe */

#ifdef HAVE_STRERROR_R

  /* There are two different APIs for strerror_r(). The POSIX and the GLIBC

     versions. */

#ifdef HAVE_POSIX_STRERROR_R

  strerror_r(err, buf, max);

  /* this may set errno to ERANGE if insufficient storage was supplied via

     'strerrbuf' and 'buflen' to contain the generated message string, or

     EINVAL if the value of 'errnum' is not a valid error number.*/

#else

#if defined(HAVE_STRERROR_R) && defined(HAVE_POSIX_STRERROR_R)

 /*

  * The POSIX-style strerror_r() may set errno to ERANGE if insufficient

  * storage is supplied via 'strerrbuf' and 'buflen' to hold the generated

  * message string, or EINVAL if 'errnum' is not a valid error number.

  */

  if(0 != strerror_r(err, buf, max)) {

    if('\0' == buf[0])

      snprintf(buf, max, "Unknown error %d", err);

  }

#elif defined(HAVE_STRERROR_R) && defined(HAVE_GLIBC_STRERROR_R)

 /*

  * The glibc-style strerror_r() only *might* use the buffer we pass to

  * the function, but it always returns the error message as a pointer,

  * so we must copy that string unconditionally (if non-NULL).

  */

  {

    /* HAVE_GLIBC_STRERROR_R */

    char buffer[256];

    char *msg = strerror_r(err, buffer, sizeof(buffer));

    /* this version of strerror_r() only *might* use the buffer we pass to

       the function, but it always returns the error message as a pointer,

       so we must copy that string unconditionally (if non-NULL) */

    if(msg)

      strncpy(buf, msg, max);

    else

      snprintf(buf, max, "Unknown error %d", err);

  }

#endif /* end of HAVE_GLIBC_STRERROR_R */

#else /* HAVE_STRERROR_R */

  strncpy(buf, strerror(err), max);

#endif /* end of HAVE_STRERROR_R */

#else

  {

    char *msg = strerror(err);

    if(msg)

      strncpy(buf, msg, max);

    else

      snprintf(buf, max, "Unknown error %d", err);

  }

#endif



#endif /* end of ! USE_WINSOCK */



  buf[max] = '\0'; /* make sure the string is zero terminated */
@@ -659,6 +660,10 @@ const char *Curl_strerror(struct connectdata *conn, int err) 
     *p = '\0';

  if((p = strrchr(buf,'\r')) != NULL && (p - buf) >= 1)

     *p = '\0';



  if(old_errno != ERRNO)

    SET_ERRNO(old_errno);



  return buf;

}
@@ -680,6 +685,7 @@ const char *Curl_idn_strerror (struct connectdata *conn, int err) 


  buf = conn->syserr_buf;

  max = sizeof(conn->syserr_buf)-1;

  *buf = '\0';



#ifndef CURL_DISABLE_VERBOSE_STRINGS

  switch ((Idna_rc)err) {