diff options
| -rw-r--r-- | lib/strerror.c | 56 |
1 files changed, 34 insertions, 22 deletions
diff --git a/lib/strerror.c b/lib/strerror.c index 4b1df9446..03ddc1a2b 100644 --- a/lib/strerror.c +++ b/lib/strerror.c @@ -485,12 +485,16 @@ get_winsock_error (int err, char *buf, size_t len) } #endif /* WIN32 && !__CYGWIN__ */ -#ifndef WIN32 -extern int sys_nerr; -#endif - /* * Our thread-safe and smart strerror() replacement. + * + * The 'err' argument passed in to this function MUST be a true errno number + * as reported on this system. We do no range checking on the number before + * we pass it to the "number-to-message" convertion function and there might + * be systems that don't do proper range checking in there themselves. + * + * We don't do range checking (on systems other than Windows) since there is + * no good reliable and portable way to do it. */ const char *Curl_strerror(struct connectdata *conn, int err) { @@ -498,37 +502,45 @@ const char *Curl_strerror(struct connectdata *conn, int err) size_t max; curlassert(conn); + curlassert(err >= 0); buf = conn->syserr_buf; max = sizeof(conn->syserr_buf)-1; *buf = '\0'; + +#if defined(WIN32) && !defined(__CYGWIN__) + /* 'sys_nerr' is the maximum errno number, it is not widely portable */ if (err >= 0 && err < sys_nerr) { - /* These should be atomic and hopefully thread-safe */ + if (!get_winsock_error (err, buf, max) && + !FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM, NULL, err, + LANG_NEUTRAL, buf, max, NULL)) + snprintf(buf, max, "Unknown error %d (%#x)", err, err); + } +#else /* not native Windows 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.*/ + 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 + { /* HAVE_GLIBC_STRERROR_R */ char buffer[256]; char *msg = strerror_r(err, buffer, sizeof(buffer)); strncpy(buf, msg, max); -#endif -#else - strncpy(buf, strerror(err), max); -#endif - *(buf+max) = '\0'; - } - else { -#if defined(WIN32) && !defined(__CYGWIN__) - if (!get_winsock_error (err, buf, max) && - !FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM, NULL, err, - LANG_NEUTRAL, buf, max, NULL)) -#endif - snprintf(buf, max, "Unknown error %d (%#x)", err, err); } +#endif /* end of HAVE_GLIBC_STRERROR_R */ +#else /* HAVE_STRERROR_R */ + strncpy(buf, strerror(err), max); +#endif /* end of HAVE_STRERROR_R */ +#endif /* end of ! Windows */ + + buf[max] = '\0'; /* make sure the string is zero terminated */ /* strip trailing '\r\n' or '\n'. */ if ((p = strrchr(buf,'\n')) != NULL && (p - buf) >= 2) |