/***************************************************************************

 *                                  _   _ ____  _

 *  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 "curl_setup.h"

#ifdef CURL_MEMDEBUG

#include <stddef.h>  /* for offsetof() */

#include "urldata.h"

#include "curl_threads.h"

#include "curlx/fopen.h"  /* for CURLX_FOPEN_LOW(), CURLX_FREOPEN_LOW() */

#ifdef USE_BACKTRACE

#include <backtrace.h>

#endif

struct memdebug {

  size_t size;

  union {

    curl_off_t o;

    double d;

    void *p;

  } mem[1];

  /* I am hoping this is the thing with the strictest alignment

   * requirements. That also means we waste some space :-( */

};

/*

 * Note that these debug functions are simple and they are meant to remain so.

 * For advanced analysis, record a log file and write perl scripts to analyze

 * them!

 *

 * Do not use these with multi-threaded test programs!

 */

FILE *curl_dbg_logfile = NULL;

static bool registered_cleanup = FALSE; /* atexit registered cleanup */

static bool memlimit = FALSE; /* enable memory limit */

static long memsize = 0;  /* set number of mallocs allowed */

#ifdef USE_BACKTRACE

static struct backtrace_state *btstate;

#endif

static char membuf[10000];

static size_t memwidx = 0; /* write index */

#ifdef USE_MUTEX

static bool dbg_mutex_init = 0;

static curl_mutex_t dbg_mutex;

#endif

static bool curl_dbg_lock(void)

{

#ifdef USE_MUTEX

  if(dbg_mutex_init) {

    Curl_mutex_acquire(&dbg_mutex);

    return TRUE;

  }

#endif

  return FALSE;

}

static void curl_dbg_unlock(bool was_locked)

{

#ifdef USE_MUTEX

  if(was_locked)

    Curl_mutex_release(&dbg_mutex);

#else

  (void)was_locked;

#endif

}

static void curl_dbg_log_locked(const char *format, ...) CURL_PRINTF(1, 2);

/* LeakSantizier (LSAN) calls _exit() instead of exit() when a leak is detected

   on exit so the logfile must be closed explicitly or data could be lost.

   Though _exit() does not call atexit handlers such as this, LSAN's call to

   _exit() comes after the atexit handlers are called. curl/curl#6620 */

static void curl_dbg_cleanup(void)

{

  bool locked = curl_dbg_lock();

  if(curl_dbg_logfile &&

     curl_dbg_logfile != stderr &&

     curl_dbg_logfile != stdout) {

    if(memwidx)

      fwrite(membuf, 1, memwidx, curl_dbg_logfile);

    /* !checksrc! disable BANNEDFUNC 1 */

    fclose(curl_dbg_logfile);

  }

  curl_dbg_logfile = NULL;

  curl_dbg_unlock(locked);

#ifdef USE_MUTEX

  if(dbg_mutex_init) {

    Curl_mutex_destroy(&dbg_mutex);

    dbg_mutex_init = FALSE;

  }

#endif

}

#ifdef USE_BACKTRACE

static void error_bt_callback(void *data, const char *message,

                              int error_number)

{

  (void)data;

  if(error_number == -1)

    curl_dbg_log("compile with -g\n\n");

  else

    curl_dbg_log("Backtrace error %d: %s\n", error_number, message);

}

static int full_callback(void *data, uintptr_t pc, const char *pathname,

                         int line_number, const char *function)

{

  (void)data;

  (void)pc;

  if(pathname || function || line_number)

    curl_dbg_log("BT %s:%d -- %s\n", pathname, line_number, function);

  return 0;

}

static void dump_bt(void)

{

  backtrace_full(btstate, 0, full_callback, error_bt_callback, NULL);

}

#else

#define dump_bt() /* nothing to do */

#endif

/* this sets the log filename */

void curl_dbg_memdebug(const char *logname)

{

  if(!curl_dbg_logfile) {

    if(logname && *logname)

      curl_dbg_logfile = CURLX_FOPEN_LOW(logname, FOPEN_WRITETEXT);

#ifdef MEMDEBUG_LOG_SYNC

    /* Flush the log file after every line so the log is not lost in a crash */

    if(curl_dbg_logfile)

      setbuf(curl_dbg_logfile, (char *)NULL);

#endif

  }

#ifdef USE_MUTEX

  if(!dbg_mutex_init) {

    dbg_mutex_init = TRUE;

    Curl_mutex_init(&dbg_mutex);

  }

#endif

#ifdef USE_BACKTRACE

  btstate = backtrace_create_state(NULL, 0, error_bt_callback, NULL);

#endif

  if(!registered_cleanup)

    registered_cleanup = !atexit(curl_dbg_cleanup);

}

/* This function sets the number of malloc() calls that should return

   successfully! */

void curl_dbg_memlimit(long limit)

{

  if(!memlimit) {

    memlimit = TRUE;

    memsize = limit;

  }

}

/* returns TRUE if this is not allowed! */

static bool countcheck(const char *func, int line, const char *source)

{

  /* if source is NULL, then the call is made internally and this check

     should not be made */

  if(memlimit && source) {

    if(!memsize) {

      /* log to file */

      curl_dbg_log("LIMIT %s:%d %s reached memlimit\n", source, line, func);

      /* log to stderr also */

      curl_mfprintf(stderr, "LIMIT %s:%d %s reached memlimit\n",

                    source, line, func);

      dump_bt();

      fflush(curl_dbg_logfile); /* because it might crash now */

      /* !checksrc! disable ERRNOVAR 1 */

      errno = ENOMEM;

      return TRUE; /* RETURN ERROR! */

    }

    else

      memsize--; /* countdown */

  }

  return FALSE; /* allow this */

}

ALLOC_FUNC

void *curl_dbg_malloc(size_t wantedsize, int line, const char *source)

{

  struct memdebug *mem;

  size_t size;

  DEBUGASSERT(wantedsize != 0);

  if(countcheck("malloc", line, source))

    return NULL;

  /* alloc at least 64 bytes */

  size = sizeof(struct memdebug) + wantedsize;

  mem = Curl_cmalloc(size);

  if(mem) {

    mem->size = wantedsize;

  }

  if(source)

    curl_dbg_log("MEM %s:%d malloc(%zu) = %p\n",

                 source, line, wantedsize,

                 mem ? (void *)mem->mem : (void *)0);

  return mem ? mem->mem : NULL;

}

ALLOC_FUNC

void *curl_dbg_calloc(size_t wanted_elements, size_t wanted_size,

                      int line, const char *source)

{

  struct memdebug *mem;

  size_t size, user_size;

  DEBUGASSERT(wanted_elements != 0);

  DEBUGASSERT(wanted_size != 0);

  if(countcheck("calloc", line, source))

    return NULL;

  /* alloc at least 64 bytes */

  user_size = wanted_size * wanted_elements;

  size = sizeof(struct memdebug) + user_size;

  mem = Curl_ccalloc(1, size);

  if(mem)

    mem->size = user_size;

  if(source)

    curl_dbg_log("MEM %s:%d calloc(%zu,%zu) = %p\n",

                 source, line, wanted_elements, wanted_size,

                 mem ? (void *)mem->mem : (void *)0);

  return mem ? mem->mem : NULL;

}

ALLOC_FUNC

char *curl_dbg_strdup(const char *str, int line, const char *source)

{

  char *mem;

  size_t len;

  DEBUGASSERT(str != NULL);

  if(countcheck("strdup", line, source))

    return NULL;

  len = strlen(str) + 1;

  mem = curl_dbg_malloc(len, 0, NULL); /* NULL prevents logging */

  if(mem)

    memcpy(mem, str, len);

  if(source)

    curl_dbg_log("MEM %s:%d strdup(%p) (%zu) = %p\n",

                 source, line, (const void *)str, len, (const void *)mem);

  return mem;

}

#if defined(_WIN32) && defined(UNICODE)

ALLOC_FUNC

wchar_t *curl_dbg_wcsdup(const wchar_t *str, int line, const char *source)

{

  wchar_t *mem;

  size_t wsiz, bsiz;

  DEBUGASSERT(str != NULL);

  if(countcheck("wcsdup", line, source))

    return NULL;

  wsiz = wcslen(str) + 1;

  bsiz = wsiz * sizeof(wchar_t);

  mem = curl_dbg_malloc(bsiz, 0, NULL); /* NULL prevents logging */

  if(mem)

    memcpy(mem, str, bsiz);

  if(source)

    curl_dbg_log("MEM %s:%d wcsdup(%p) (%zu) = %p\n",

                source, line, (const void *)str, bsiz, (void *)mem);

  return mem;

}

#endif

/* We provide a realloc() that accepts a NULL as pointer, which then

   performs a malloc(). In order to work with ares. */

void *curl_dbg_realloc(void *ptr, size_t wantedsize,

                       int line, const char *source)

{

  struct memdebug *mem = NULL;

  bool was_locked;

  size_t size = sizeof(struct memdebug) + wantedsize;

  DEBUGASSERT(wantedsize != 0);

  if(countcheck("realloc", line, source))

    return NULL;

  /* need to realloc under lock, as we get out-of-order log

   * entries otherwise, since another thread might alloc the

   * memory released by realloc() before otherwise would log it. */

  was_locked = curl_dbg_lock();

#ifdef __INTEL_COMPILER

#  pragma warning(push)

#  pragma warning(disable:1684)

   /* 1684: conversion from pointer to same-sized integral type */

#endif

  if(ptr)

    mem = (void *)((char *)ptr - offsetof(struct memdebug, mem));

#ifdef __INTEL_COMPILER

#  pragma warning(pop)

#endif

  mem = Curl_crealloc(mem, size);

  if(source)

    curl_dbg_log_locked("MEM %s:%d realloc(%p, %zu) = %p\n",

                        source, line, (void *)ptr, wantedsize,

                        mem ? (void *)mem->mem : (void *)0);

  curl_dbg_unlock(was_locked);

  if(mem) {

    mem->size = wantedsize;

    return mem->mem;

  }

  return NULL;

}

void curl_dbg_free(void *ptr, int line, const char *source)

{

  if(ptr) {

    struct memdebug *mem;

    if(source)

      curl_dbg_log("MEM %s:%d free(%p)\n", source, line, (void *)ptr);

#ifdef __INTEL_COMPILER

#  pragma warning(push)

#  pragma warning(disable:1684)

   /* 1684: conversion from pointer to same-sized integral type */

#endif

    mem = (void *)((char *)ptr - offsetof(struct memdebug, mem));

#ifdef __INTEL_COMPILER

#  pragma warning(pop)

#endif

    /* free for real */

    Curl_cfree(mem);

  }

}

curl_socket_t curl_dbg_socket(int domain, int type, int protocol,

                              int line, const char *source)

{

  curl_socket_t sockfd;

  if(countcheck("socket", line, source))

    return CURL_SOCKET_BAD;

  /* !checksrc! disable BANNEDFUNC 1 */

  sockfd = socket(domain, type, protocol);

  if(source && (sockfd != CURL_SOCKET_BAD))

    curl_dbg_log("FD %s:%d socket() = %" FMT_SOCKET_T "\n",

                 source, line, sockfd);

  return sockfd;

}

#ifdef HAVE_SOCKETPAIR

int curl_dbg_socketpair(int domain, int type, int protocol,

                        curl_socket_t socket_vector[2],

                        int line, const char *source)

{

  /* !checksrc! disable BANNEDFUNC 1 */

  int res = socketpair(domain, type, protocol, socket_vector);

  if(source && (res == 0))

    curl_dbg_log("FD %s:%d socketpair() = "

                 "%" FMT_SOCKET_T " %" FMT_SOCKET_T "\n",

                 source, line, socket_vector[0], socket_vector[1]);

  return res;

}

#endif

curl_socket_t curl_dbg_accept(curl_socket_t s, void *saddr, void *saddrlen,

                              int line, const char *source)

{

  struct sockaddr *addr = (struct sockaddr *)saddr;

  curl_socklen_t *addrlen = (curl_socklen_t *)saddrlen;

  /* !checksrc! disable BANNEDFUNC 1 */

  curl_socket_t sockfd = accept(s, addr, addrlen);

  if(source && (sockfd != CURL_SOCKET_BAD))

    curl_dbg_log("FD %s:%d accept() = %" FMT_SOCKET_T "\n",

                 source, line, sockfd);

  return sockfd;

}

#ifdef HAVE_ACCEPT4

curl_socket_t curl_dbg_accept4(curl_socket_t s, void *saddr, void *saddrlen,

                               int flags,

                               int line, const char *source)

{

  struct sockaddr *addr = (struct sockaddr *)saddr;

  curl_socklen_t *addrlen = (curl_socklen_t *)saddrlen;

  /* !checksrc! disable BANNEDFUNC 1 */

  curl_socket_t sockfd = accept4(s, addr, addrlen, flags);

  if(source && (sockfd != CURL_SOCKET_BAD))

    curl_dbg_log("FD %s:%d accept() = %" FMT_SOCKET_T "\n",

                 source, line, sockfd);

  return sockfd;

}

#endif

/* separate function to allow libcurl to mark a "faked" close */

void curl_dbg_mark_sclose(curl_socket_t sockfd, int line, const char *source)

{

  if(source)

    curl_dbg_log("FD %s:%d sclose(%" FMT_SOCKET_T ")\n",

                 source, line, sockfd);

}

/* this is our own defined way to close sockets on *ALL* platforms */

int curl_dbg_sclose(curl_socket_t sockfd, int line, const char *source)

{

  curl_dbg_mark_sclose(sockfd, line, source);

  return CURL_SCLOSE(sockfd);

}

ALLOC_FUNC

FILE *curl_dbg_fopen(const char *file, const char *mode,

                     int line, const char *source)

{

  FILE *res = CURLX_FOPEN_LOW(file, mode);

  if(source)

    curl_dbg_log("FILE %s:%d fopen(\"%s\",\"%s\") = %p\n",

                 source, line, file, mode, (void *)res);

  return res;

}

ALLOC_FUNC

FILE *curl_dbg_freopen(const char *file, const char *mode, FILE *fh,

                       int line, const char *source)

{

  FILE *res = CURLX_FREOPEN_LOW(file, mode, fh);

  if(source)

    curl_dbg_log("FILE %s:%d freopen(\"%s\",\"%s\",%p) = %p\n",

                 source, line, file, mode, (void *)fh, (void *)res);

  return res;

}

ALLOC_FUNC

FILE *curl_dbg_fdopen(int filedes, const char *mode,

                      int line, const char *source)

{

  FILE *res = CURLX_FDOPEN_LOW(filedes, mode);

  if(source)

    curl_dbg_log("FILE %s:%d fdopen(\"%d\",\"%s\") = %p\n",

                 source, line, filedes, mode, (void *)res);

  return res;

}

int curl_dbg_fclose(FILE *file, int line, const char *source)

{

  int res;

  DEBUGASSERT(file != NULL);

  if(source)

    curl_dbg_log("FILE %s:%d fclose(%p)\n", source, line, (void *)file);

  /* !checksrc! disable BANNEDFUNC 1 */

  res = fclose(file);

  return res;

}

static void curl_dbg_vlog(const char * const fmt,

                          va_list ap) CURL_PRINTF(1, 0);

static void curl_dbg_vlog(const char * const fmt, va_list ap)

{

  char buf[1024];

  size_t nchars = curl_mvsnprintf(buf, sizeof(buf), fmt, ap);

  if(nchars > (int)sizeof(buf) - 1)

    nchars = (int)sizeof(buf) - 1;

  if(nchars > 0) {

    if(sizeof(membuf) - nchars < memwidx) {

      /* flush */

      fwrite(membuf, 1, memwidx, curl_dbg_logfile);

      fflush(curl_dbg_logfile);

      memwidx = 0;

    }

    if(memwidx) {

      /* the previous line ends with a newline */

      DEBUGASSERT(membuf[memwidx - 1] == '\n');

    }

    memcpy(&membuf[memwidx], buf, nchars);

    memwidx += nchars;

  }

}

static void curl_dbg_log_locked(const char *format, ...)

{

  va_list ap;

  if(!curl_dbg_logfile)

    return;

  va_start(ap, format);

  curl_dbg_vlog(format, ap);

  va_end(ap);

}

/* this does the writing to the memory tracking log file */

void curl_dbg_log(const char *format, ...)

{

  bool was_locked;

  va_list ap;

  if(!curl_dbg_logfile)

    return;

  was_locked = curl_dbg_lock();

  va_start(ap, format);

  curl_dbg_vlog(format, ap);

  va_end(ap);

  curl_dbg_unlock(was_locked);

}

#endif /* CURL_MEMDEBUG */