src/tool_msgs.c - master - githubmirror/curl

src/tool_msgs.c
137 строк4 KB
Daniel Stenberg
tool_msgs: avoid null pointer deref for early errors
18 мар 2026, 12:40
18 мар 2026, 12:40acb4fcb
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * SPDX-License-Identifier: curl
 *
 ***************************************************************************/
#include "tool_setup.h"

#include "tool_cfgable.h"
#include "tool_msgs.h"
#include "terminal.h"

#define WARN_PREFIX  "Warning: "
#define NOTE_PREFIX  "Note: "
#define ERROR_PREFIX "curl: "

static void voutf(const char *prefix, const char *fmt, va_list ap)
  CURL_PRINTF(2, 0);

static void voutf(const char *prefix, const char *fmt, va_list ap)
{
  size_t len;
  char *ptr;
  char buffer[1024];
  size_t termw = get_terminal_columns();
  size_t prefw = strlen(prefix);
  size_t width = termw > prefw ? termw - prefw : SIZE_MAX;
  DEBUGASSERT(!strchr(fmt, '\n'));
  len = curl_mvsnprintf(buffer, sizeof(buffer), fmt, ap);
  ptr = buffer;
  while(len > 0) {
    fputs(prefix, tool_stderr);

    if(len > width) {
      size_t cut = width - 1;

      while(!ISBLANK(ptr[cut]) && cut) {
        cut--;
      }
      if(cut == 0)
        /* not a single cutting position was found, cut it at the max text
           width then! */
        cut = width - 1;

      (void)fwrite(ptr, cut + 1, 1, tool_stderr);
      fputs("\n", tool_stderr);
      ptr += cut + 1; /* skip the space too */
      len -= cut + 1;
    }
    else {
      fputs(ptr, tool_stderr);
      fputs("\n", tool_stderr);
      len = 0;
    }
  }
}

/*
 * Emit 'note' formatted message on configured 'errors' stream, if verbose was
 * selected.
 */
void notef(const char *fmt, ...)
{
  if(global && global->tracetype) {
    va_list ap;
    va_start(ap, fmt);
    voutf(NOTE_PREFIX, fmt, ap);
    va_end(ap);
  }
}

/*
 * Emit warning formatted message on configured 'errors' stream unless
 * mute (--silent) was selected.
 */
void warnf(const char *fmt, ...)
{
  if(!global || !global->silent) {
    va_list ap;
    va_start(ap, fmt);
    voutf(WARN_PREFIX, fmt, ap);
    va_end(ap);
  }
}

/*
 * Emit help formatted message on given stream. This is for errors with or
 * related to command line arguments.
 */
void helpf(const char *fmt, ...)
{
  if(fmt) {
    va_list ap;
    va_start(ap, fmt);
    DEBUGASSERT(!strchr(fmt, '\n'));
    fputs("curl: ", tool_stderr); /* prefix it */
    curl_mvfprintf(tool_stderr, fmt, ap);
    va_end(ap);
    fputs("\n", tool_stderr); /* newline it */
  }
  curl_mfprintf(tool_stderr, "curl: try 'curl --help' "
#ifdef USE_MANUAL
                             "or 'curl --manual' "
#endif
                             "for more information\n");
}

/*
 * Emit error message on error stream if not muted. When errors are not tied
 * to command line arguments, use helpf() for such errors.
 */
void errorf(const char *fmt, ...)
{
  if(!global || !global->silent || global->showerror) {
    va_list ap;
    va_start(ap, fmt);
    voutf(ERROR_PREFIX, fmt, ap);
    va_end(ap);
  }
}