/src/curl/lib/api.c

Source
/***************************************************************************
 *                                  _   _ ____  _
 *  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"

#include "urldata.h"
#include "api.h"
#include "curl_threads.h"
#include "multiif.h"
#include "vtls/vtls_scache.h"

struct Curl_eapi_fn_props {
  Curl_eapi_fn fn;
  uint8_t data_is_killed; /* easy handle is killed in call */
  uint8_t recurse;        /* may be called when another call is in progress */
  uint8_t no_event_cb;    /* may not be called during a multi event callback */
  uint8_t no_scache_lock; /* may not be called with easy's vtls_scache
                             locked by current thread */
};

static const struct Curl_eapi_fn_props eapi_fn_props[CURL_EAPI_FN_LAST] = {
  /* function                   kill rec !ev !scach */
  { CURL_EAPI_FN_easy_cleanup,     1,  0,  0,  0 },
  { CURL_EAPI_FN_easy_duphandle,   0,  1,  0,  0 },
  { CURL_EAPI_FN_easy_getinfo,     0,  1,  0,  0 },
  { CURL_EAPI_FN_easy_header,      0,  1,  0,  0 },
  { CURL_EAPI_FN_easy_nextheader,  0,  1,  0,  0 },
  { CURL_EAPI_FN_easy_pause,       0,  1,  1,  0 },
  { CURL_EAPI_FN_easy_perform_ev,  0,  0,  0,  1 },
  { CURL_EAPI_FN_easy_perform,     0,  0,  0,  1 },
  { CURL_EAPI_FN_easy_recv,        0,  0,  0,  1 },
  { CURL_EAPI_FN_easy_reset,       0,  0,  0,  0 },
  { CURL_EAPI_FN_easy_send,        0,  0,  0,  1 },
  { CURL_EAPI_FN_easy_setopt,      0,  1,  0,  0 },
  { CURL_EAPI_FN_easy_ssls_export, 0,  0,  0,  1 },
  { CURL_EAPI_FN_easy_ssls_import, 0,  0,  0,  1 },
  { CURL_EAPI_FN_easy_upkeep,      0,  0,  0,  1 },
  { CURL_EAPI_FN_ws_recv,          0,  1,  0,  1 },
  { CURL_EAPI_FN_ws_send,          0,  1,  0,  1 },
  { CURL_EAPI_FN_ws_start_frame,   0,  1,  0,  0 },
};

struct Curl_mapi_fn_props {
  Curl_mapi_fn fn;
  uint8_t multi_is_killed; /* multi handle is killed during call */
  uint8_t recurse;         /* may be called when another call is in progress */
  uint8_t allow_ntfy_cb;   /* may be called during a notify callback */
  uint8_t no_scache_lock;  /* may not be called with multi's vtls_scache
                              locked by current thread */
};

static const struct Curl_mapi_fn_props mapi_fn_props[CURL_MAPI_FN_LAST] = {
  /* function                       kill rec ntfy !scach */
  { CURL_MAPI_FN_multi_add_handle,     0,  0,   1,  0 },
  { CURL_MAPI_FN_multi_assign,         0,  1,   1,  0 },
  { CURL_MAPI_FN_multi_cleanup,        1,  0,   0,  1 },
  { CURL_MAPI_FN_multi_fdset,          0,  0,   1,  0 },
  { CURL_MAPI_FN_multi_get_handles,    0,  1,   1,  0 },
  { CURL_MAPI_FN_multi_get_offt,       0,  1,   1,  0 },
  { CURL_MAPI_FN_multi_info_read,      0,  1,   1,  0 },
  { CURL_MAPI_FN_multi_notify_disable, 0,  1,   1,  0 },
  { CURL_MAPI_FN_multi_notify_enable,  0,  1,   1,  0 },
  { CURL_MAPI_FN_multi_perform,        0,  0,   0,  1 },
  { CURL_MAPI_FN_multi_poll,           0,  0,   1,  0 },
  { CURL_MAPI_FN_multi_remove_handle,  0,  0,   1,  0 },
  { CURL_MAPI_FN_multi_setopt,         0,  0,   1,  0 },
  { CURL_MAPI_FN_multi_socket_action,  0,  0,   0,  1 },
  { CURL_MAPI_FN_multi_socket_all,     0,  0,   0,  1 },
  { CURL_MAPI_FN_multi_socket,         0,  0,   0,  1 },
  { CURL_MAPI_FN_multi_timeout,        0,  0,   1,  1 },
  { CURL_MAPI_FN_multi_wait,           0,  0,   1,  0 },
  { CURL_MAPI_FN_multi_waitfds,        0,  0,   1,  0 },
};

struct Curl_cbapi_fn_props {
  Curl_cbapi_fn fn;
  uint8_t is_event_cb;     /* is a multi event processing callback */
};

static const struct Curl_cbapi_fn_props
cbapi_fn_props[CURL_CBAPI_FN_LAST - CURL_CBAPI_FN_START] = {
  { CURL_CBAPI_FN_easy_chunk_bgn,             0 },
  { CURL_CBAPI_FN_easy_chunk_end,             0 },
  { CURL_CBAPI_FN_easy_closesocket,           0 },
  { CURL_CBAPI_FN_easy_cr_in_read,            0 },
  { CURL_CBAPI_FN_easy_cr_in_resume_from,     0 },
  { CURL_CBAPI_FN_easy_cw_out_cb,             0 },
  { CURL_CBAPI_FN_easy_fdebug,                0 },
  { CURL_CBAPI_FN_easy_fnmatch_data,          0 },
  { CURL_CBAPI_FN_easy_fopensocket,           0 },
  { CURL_CBAPI_FN_easy_fprereq,               0 },
  { CURL_CBAPI_FN_easy_fprogress,             0 },
  { CURL_CBAPI_FN_easy_fread_func,            0 },
  { CURL_CBAPI_FN_easy_fsockopt,              0 },
  { CURL_CBAPI_FN_easy_fsslctx,               0 },
  { CURL_CBAPI_FN_easy_fwrite_rtp,            0 },
  { CURL_CBAPI_FN_easy_fxferinfo,             0 },
  { CURL_CBAPI_FN_easy_ioctl_func,            0 },
  { CURL_CBAPI_FN_easy_resolver_start,        0 },
  { CURL_CBAPI_FN_easy_seek_func,             0 },
  { CURL_CBAPI_FN_easy_ssh_hostkeyfunc,       0 },
  { CURL_CBAPI_FN_easy_ssh_keyfunc,           0 },
  { CURL_CBAPI_FN_easy_trailer_callback,      0 },

  { CURL_CBAPI_FN_multi_ntfy_cb,              0 },
  { CURL_CBAPI_FN_multi_push_cb,              0 },
  { CURL_CBAPI_FN_multi_socket_cb,            1 },
  { CURL_CBAPI_FN_multi_timer_cb,             1 },
};

static bool eapi_in_event_cb(struct Curl_easy *data)
{
  struct Curl_multi *multi = data->multi;
  if(multi && multi->callstack.count) {
    size_t i;
    for(i = 0; i < multi->callstack.count; ++i) {
      if(multi->callstack.calls[i] >= CURL_CBAPI_FN_START) {
        uint16_t fn = multi->callstack.calls[i];
        if((fn < CURL_CBAPI_FN_LAST) &&
           cbapi_fn_props[fn - CURL_CBAPI_FN_START].is_event_cb)
          return TRUE;
      }
    }
  }
  return FALSE;
}

static bool mapi_in_ntfy_cb(struct Curl_multi *multi)
{
  if(multi && multi->callstack.count) {
    size_t i;
    for(i = 0; i < multi->callstack.count; ++i) {
      if(multi->callstack.calls[i] == CURL_CBAPI_FN_multi_ntfy_cb)
        return TRUE;
    }
  }
  return FALSE;
}

bool Curl_api_multi_is_in_callback(struct Curl_multi *multi)
{
  if(multi && multi->callstack.count) {
    size_t i;
    for(i = 0; i < multi->callstack.count; ++i) {
      if(multi->callstack.calls[i] >= CURL_CBAPI_FN_START)
        return TRUE;
    }
  }
  return FALSE;
}

bool Curl_api_is_in_callback(struct Curl_easy *data)
{
  if(data && data->multi) {
    return Curl_api_multi_is_in_callback(data->multi);
  }
  return FALSE;
}

bool Curl_eapi_enter(struct Curl_eapi_guard *guard,
                     CURL *curl,
                     Curl_eapi_fn fn,
                     CURLcode *presult)
{
  struct Curl_easy *data = curl;
  const struct Curl_eapi_fn_props *fn_props;
  CURLcode result = CURLE_OK;

  guard->depth = 0;

  /* Verify that we got an easy handle we can work with. */
  if(!GOOD_EASY_HANDLE(data)) {
    result = CURLE_BAD_FUNCTION_ARGUMENT;
    goto out;
  }
  /* verify that is either not added to a multi handle OR has a
   * GOOD multi handle that knows `data` for `data->mid`. */
  if(data->mid != UINT32_MAX) {
    if(GOOD_MULTI_HANDLE(data->multi)) {
      if(!Curl_multi_knows_easy(data->multi, data)) {
        /* But multi does not know it, something is fishy, better deny call */
        DEBUGASSERT(0);
        result = CURLE_BAD_FUNCTION_ARGUMENT;
        goto out;
      }
    }
    else {
      DEBUGASSERT(0); /* data needs to have a GOOD multi handle */
      result = CURLE_BAD_FUNCTION_ARGUMENT;
      goto out;
    }
  }
  else if(data->multi) {
    DEBUGASSERT(0); /* data should not have a multi handle */
    result = CURLE_BAD_FUNCTION_ARGUMENT;
    goto out;
  }
  /* verify that the call `fn` we're about to enter is known
   * and check call properties to be admitting. */
  if(fn >= CURL_EAPI_FN_LAST) {
    result = CURLE_BAD_FUNCTION_ARGUMENT;
    goto out;
  }
  fn_props = &eapi_fn_props[fn];
  DEBUGASSERT(fn_props->fn == fn);
  if(!fn_props->recurse) {
    if(data->callstack.count) {
#ifdef CURLVERBOSE
      DEBUGF(curl_mfprintf(stderr,
        "EAPI guard: calling %hu with call to %u ongoing\n", (uint16_t)fn,
        data->callstack.calls[data->callstack.count-1]));
#endif
      result = CURLE_RECURSIVE_API_CALL;
      goto out;
    }
    if(data->multi && data->multi->callstack.count) {
#ifdef CURLVERBOSE

      DEBUGF(curl_mfprintf(stderr,
        "EAPI guard: calling %hu with multi call to %u ongoing\n",
        (uint16_t)fn,
        data->multi->callstack.calls[data->multi->callstack.count-1]));
#endif
      result = CURLE_RECURSIVE_API_CALL;
      goto out;
    }
  }

  if(fn_props->no_event_cb && eapi_in_event_cb(data)) {
    /* Not allowed to be invoked while an event cb is ongoing */
#ifdef CURLVERBOSE
      DEBUGF(curl_mfprintf(stderr,
        "EAPI guard: calling %hu while event callback ongoing\n",
        (uint16_t)fn));
#endif
    result = CURLE_RECURSIVE_API_CALL;
    goto out;
  }

#if defined(USE_SSL) && defined(USE_MUTEX)
  if(fn_props->no_scache_lock &&
     Curl_ssl_scache_is_locked_by_current_thread(data)) {
#ifdef CURLVERBOSE
      DEBUGF(curl_mfprintf(stderr,
        "EAPI guard: calling %hu while vtls_scache is locked by "
        "current thread\n", (uint16_t)fn));
#endif
    result = CURLE_RECURSIVE_API_CALL;
    goto out;
  }
#endif

  /* all fine, add to data's callstack */
  if(data->callstack.count >= CURL_EAPI_MAX_RECURSION) {
    result = CURLE_RECURSIVE_API_CALL;
    goto out;
  }
  data->callstack.calls[data->callstack.count] = (uint16_t)fn;
  ++data->callstack.count;
  guard->depth = data->callstack.count;
  guard->data = fn_props->data_is_killed ? NULL : data;

out:
  if(presult)
    *presult = result;
  return guard->depth > 0;
}

void Curl_eapi_leave(struct Curl_eapi_guard *guard)
{
  if(guard->depth) {
    /* guard->data is set when handle is supposed to stay alive during call */
    if(guard->data && GOOD_EASY_HANDLE(guard->data)) {
      if(guard->depth > guard->data->callstack.count) {
        DEBUGASSERT(0); /* something very wrong */
      }
      else {
        if(guard->depth < guard->data->callstack.count) {
          DEBUGASSERT(0); /* someone forgot to clean up */
        }
        /* reset to depth the guard was entered in */
        guard->data->callstack.count = (uint16_t)(guard->depth - 1);
      }
    }
  }
}

CURLHcode Curl_eapi_hcode(CURLcode result)
{
  switch(result) {
  case CURLE_OK:
    return CURLHE_OK;
  case CURLE_BAD_FUNCTION_ARGUMENT:
    return CURLHE_BAD_ARGUMENT;
  case CURLE_OUT_OF_MEMORY:
    return CURLHE_OUT_OF_MEMORY;
  case CURLE_NOT_BUILT_IN:
    return CURLHE_NOT_BUILT_IN;
  default:
    /* Unfortunately, we cannot convert RECURSIVE_API_CALL,
     * but since the header API is reentrant, this should not happen. */
    return CURLHE_BAD_ARGUMENT;
  }
}

bool Curl_mapi_enter(struct Curl_mapi_guard *guard,
                     CURLM *m,
                     Curl_mapi_fn fn,
                     CURLMcode *pmresult)
{
  struct Curl_multi *multi = m;
  const struct Curl_mapi_fn_props *fn_props;
  CURLMcode mresult = CURLM_OK;

  guard->depth = 0;

  /* Verify that we got an easy handle we can work with. */
  if(!GOOD_MULTI_HANDLE(multi)) {
    mresult = CURLM_BAD_HANDLE;
    goto out;
  }
  if(fn >= CURL_MAPI_FN_LAST) {
    mresult = CURLM_BAD_FUNCTION_ARGUMENT;
    goto out;
  }
  fn_props = &mapi_fn_props[fn];
  DEBUGASSERT(fn_props->fn == fn);
  if(fn_props->allow_ntfy_cb && mapi_in_ntfy_cb(multi)) {
    /* explicitly allowed, even though normal recursion may not */
  }
  else if(!fn_props->recurse && multi->callstack.count) {
#ifdef CURLVERBOSE
      DEBUGF(curl_mfprintf(stderr,
        "MAPI guard: calling %hu with call to %u ongoing\n", (uint16_t)fn,
        multi->callstack.calls[multi->callstack.count-1]));
#endif
    mresult = CURLM_RECURSIVE_API_CALL;
    goto out;
  }

#if defined(USE_SSL) && defined(USE_MUTEX)
  if(fn_props->no_scache_lock && multi->ssl_scache &&
     Curl_ssl_scache_is_locked_by_current_thread(multi->admin)) {
#ifdef CURLVERBOSE
      DEBUGF(curl_mfprintf(stderr,
        "MAPI guard: calling %hu while its vtls_scache is locked by "
        "current thread\n", (uint16_t)fn));
#endif
    mresult = CURLM_RECURSIVE_API_CALL;
    goto out;
  }
#endif

  /* all fine, add to data's callstack */
  if(multi->callstack.count >= CURL_MAPI_MAX_RECURSION) {
    mresult = CURLM_RECURSIVE_API_CALL;
    goto out;
  }
  multi->callstack.calls[multi->callstack.count] = (uint16_t)fn;
  ++multi->callstack.count;
  guard->depth = multi->callstack.count;
  guard->multi = fn_props->multi_is_killed ? NULL : multi;

out:
  if(pmresult)
    *pmresult = mresult;
  return guard->depth > 0;
}

void Curl_mapi_leave(struct Curl_mapi_guard *guard)
{
  if(guard->depth) {
    /* guard->data is set when handle is supposed to stay alive during call */
    if(guard->multi && GOOD_MULTI_HANDLE(guard->multi)) {
      if(guard->depth > guard->multi->callstack.count) {
        DEBUGASSERT(0); /* something very wrong */
      }
      else {
        if(guard->depth < guard->multi->callstack.count) {
          DEBUGASSERT(0); /* someone forgot to clean up */
        }
        /* reset to depth the guard was entered in */
        guard->multi->callstack.count = (uint16_t)(guard->depth - 1);
      }
    }
  }
}

void Curl_cbapi_enter(struct Curl_mapi_guard *guard,
                      struct Curl_easy *data,
                      struct Curl_multi *multi,
                      Curl_cbapi_fn fn)
{
  guard->depth = 0;

  if(!multi)
    multi = data ? data->multi : NULL;
  /* if not multi is involved here, just leave */
  if(!multi)
    return;
  /* invalid callback specifier? */
  if((fn >= CURL_CBAPI_FN_LAST) || (fn < CURL_CBAPI_FN_START)) {
    DEBUGASSERT(0);
    return;
  }
  DEBUGASSERT(cbapi_fn_props[fn - CURL_CBAPI_FN_START].fn == fn);
  if(multi->callstack.count) {
    size_t i;
    for(i = multi->callstack.count; i; --i) {
      if(multi->callstack.calls[i - 1] == fn) {
        /* recursive invocation of the same callback */
        DEBUGASSERT(0);
        return;
      }
    }
  }

  /* all fine, add to data's callstack */
  /* if multi callstack already at max depth, leave */
  if(multi->callstack.count >= CURL_MAPI_MAX_RECURSION)
    return;
  multi->callstack.calls[multi->callstack.count] = (uint16_t)fn;
  ++multi->callstack.count;
  guard->depth = multi->callstack.count;
  guard->multi = multi;
}

void Curl_cbapi_leave(struct Curl_mapi_guard *guard)
{
  Curl_mapi_leave(guard);
}

Coverage Report

Created: 2026-08-13 07:18

Line	Count	Source
1		/***************************************************************************
2		* _ _ ____ _
3		* Project ___\| \| \| \| _ \\| \|
4		* / __\| \| \| \| \|_) \| \|
5		* \| (__\| \|_\| \| _ <\| \|___
6		* \___\|\___/\|_\| \_\_____\|
7		*
8		* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9		*
10		* This software is licensed as described in the file COPYING, which
11		* you should have received as part of this distribution. The terms
12		* are also available at https://curl.se/docs/copyright.html.
13		*
14		* You may opt to use, copy, modify, merge, publish, distribute and/or sell
15		* copies of the Software, and permit persons to whom the Software is
16		* furnished to do so, under the terms of the COPYING file.
17		*
18		* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19		* KIND, either express or implied.
20		*
21		* SPDX-License-Identifier: curl
22		*
23		***************************************************************************/
24		#include "curl_setup.h"
25
26		#include "urldata.h"
27		#include "api.h"
28		#include "curl_threads.h"
29		#include "multiif.h"
30		#include "vtls/vtls_scache.h"
31
32		struct Curl_eapi_fn_props {
33		Curl_eapi_fn fn;
34		uint8_t data_is_killed; /* easy handle is killed in call */
35		uint8_t recurse; /* may be called when another call is in progress */
36		uint8_t no_event_cb; /* may not be called during a multi event callback */
37		uint8_t no_scache_lock; /* may not be called with easy's vtls_scache
38		locked by current thread */
39		};
40
41		static const struct Curl_eapi_fn_props eapi_fn_props[CURL_EAPI_FN_LAST] = {
42		/* function kill rec !ev !scach */
43		{ CURL_EAPI_FN_easy_cleanup, 1, 0, 0, 0 },
44		{ CURL_EAPI_FN_easy_duphandle, 0, 1, 0, 0 },
45		{ CURL_EAPI_FN_easy_getinfo, 0, 1, 0, 0 },
46		{ CURL_EAPI_FN_easy_header, 0, 1, 0, 0 },
47		{ CURL_EAPI_FN_easy_nextheader, 0, 1, 0, 0 },
48		{ CURL_EAPI_FN_easy_pause, 0, 1, 1, 0 },
49		{ CURL_EAPI_FN_easy_perform_ev, 0, 0, 0, 1 },
50		{ CURL_EAPI_FN_easy_perform, 0, 0, 0, 1 },
51		{ CURL_EAPI_FN_easy_recv, 0, 0, 0, 1 },
52		{ CURL_EAPI_FN_easy_reset, 0, 0, 0, 0 },
53		{ CURL_EAPI_FN_easy_send, 0, 0, 0, 1 },
54		{ CURL_EAPI_FN_easy_setopt, 0, 1, 0, 0 },
55		{ CURL_EAPI_FN_easy_ssls_export, 0, 0, 0, 1 },
56		{ CURL_EAPI_FN_easy_ssls_import, 0, 0, 0, 1 },
57		{ CURL_EAPI_FN_easy_upkeep, 0, 0, 0, 1 },
58		{ CURL_EAPI_FN_ws_recv, 0, 1, 0, 1 },
59		{ CURL_EAPI_FN_ws_send, 0, 1, 0, 1 },
60		{ CURL_EAPI_FN_ws_start_frame, 0, 1, 0, 0 },
61		};
62
63		struct Curl_mapi_fn_props {
64		Curl_mapi_fn fn;
65		uint8_t multi_is_killed; /* multi handle is killed during call */
66		uint8_t recurse; /* may be called when another call is in progress */
67		uint8_t allow_ntfy_cb; /* may be called during a notify callback */
68		uint8_t no_scache_lock; /* may not be called with multi's vtls_scache
69		locked by current thread */
70		};
71
72		static const struct Curl_mapi_fn_props mapi_fn_props[CURL_MAPI_FN_LAST] = {
73		/* function kill rec ntfy !scach */
74		{ CURL_MAPI_FN_multi_add_handle, 0, 0, 1, 0 },
75		{ CURL_MAPI_FN_multi_assign, 0, 1, 1, 0 },
76		{ CURL_MAPI_FN_multi_cleanup, 1, 0, 0, 1 },
77		{ CURL_MAPI_FN_multi_fdset, 0, 0, 1, 0 },
78		{ CURL_MAPI_FN_multi_get_handles, 0, 1, 1, 0 },
79		{ CURL_MAPI_FN_multi_get_offt, 0, 1, 1, 0 },
80		{ CURL_MAPI_FN_multi_info_read, 0, 1, 1, 0 },
81		{ CURL_MAPI_FN_multi_notify_disable, 0, 1, 1, 0 },
82		{ CURL_MAPI_FN_multi_notify_enable, 0, 1, 1, 0 },
83		{ CURL_MAPI_FN_multi_perform, 0, 0, 0, 1 },
84		{ CURL_MAPI_FN_multi_poll, 0, 0, 1, 0 },
85		{ CURL_MAPI_FN_multi_remove_handle, 0, 0, 1, 0 },
86		{ CURL_MAPI_FN_multi_setopt, 0, 0, 1, 0 },
87		{ CURL_MAPI_FN_multi_socket_action, 0, 0, 0, 1 },
88		{ CURL_MAPI_FN_multi_socket_all, 0, 0, 0, 1 },
89		{ CURL_MAPI_FN_multi_socket, 0, 0, 0, 1 },
90		{ CURL_MAPI_FN_multi_timeout, 0, 0, 1, 1 },
91		{ CURL_MAPI_FN_multi_wait, 0, 0, 1, 0 },
92		{ CURL_MAPI_FN_multi_waitfds, 0, 0, 1, 0 },
93		};
94
95		struct Curl_cbapi_fn_props {
96		Curl_cbapi_fn fn;
97		uint8_t is_event_cb; /* is a multi event processing callback */
98		};
99
100		static const struct Curl_cbapi_fn_props
101		cbapi_fn_props[CURL_CBAPI_FN_LAST - CURL_CBAPI_FN_START] = {
102		{ CURL_CBAPI_FN_easy_chunk_bgn, 0 },
103		{ CURL_CBAPI_FN_easy_chunk_end, 0 },
104		{ CURL_CBAPI_FN_easy_closesocket, 0 },
105		{ CURL_CBAPI_FN_easy_cr_in_read, 0 },
106		{ CURL_CBAPI_FN_easy_cr_in_resume_from, 0 },
107		{ CURL_CBAPI_FN_easy_cw_out_cb, 0 },
108		{ CURL_CBAPI_FN_easy_fdebug, 0 },
109		{ CURL_CBAPI_FN_easy_fnmatch_data, 0 },
110		{ CURL_CBAPI_FN_easy_fopensocket, 0 },
111		{ CURL_CBAPI_FN_easy_fprereq, 0 },
112		{ CURL_CBAPI_FN_easy_fprogress, 0 },
113		{ CURL_CBAPI_FN_easy_fread_func, 0 },
114		{ CURL_CBAPI_FN_easy_fsockopt, 0 },
115		{ CURL_CBAPI_FN_easy_fsslctx, 0 },
116		{ CURL_CBAPI_FN_easy_fwrite_rtp, 0 },
117		{ CURL_CBAPI_FN_easy_fxferinfo, 0 },
118		{ CURL_CBAPI_FN_easy_ioctl_func, 0 },
119		{ CURL_CBAPI_FN_easy_resolver_start, 0 },
120		{ CURL_CBAPI_FN_easy_seek_func, 0 },
121		{ CURL_CBAPI_FN_easy_ssh_hostkeyfunc, 0 },
122		{ CURL_CBAPI_FN_easy_ssh_keyfunc, 0 },
123		{ CURL_CBAPI_FN_easy_trailer_callback, 0 },
124
125		{ CURL_CBAPI_FN_multi_ntfy_cb, 0 },
126		{ CURL_CBAPI_FN_multi_push_cb, 0 },
127		{ CURL_CBAPI_FN_multi_socket_cb, 1 },
128		{ CURL_CBAPI_FN_multi_timer_cb, 1 },
129		};
130
131		static bool eapi_in_event_cb(struct Curl_easy *data)
132	0	{
133	0	struct Curl_multi *multi = data->multi;
134	0	if(multi && multi->callstack.count) {
135	0	size_t i;
136	0	for(i = 0; i < multi->callstack.count; ++i) {
137	0	if(multi->callstack.calls[i] >= CURL_CBAPI_FN_START) {
138	0	uint16_t fn = multi->callstack.calls[i];
139	0	if((fn < CURL_CBAPI_FN_LAST) &&
140	0	cbapi_fn_props[fn - CURL_CBAPI_FN_START].is_event_cb)
141	0	return TRUE;
142	0	}
143	0	}
144	0	}
145	0	return FALSE;
146	0	}
147
148		static bool mapi_in_ntfy_cb(struct Curl_multi *multi)
149	0	{
150	0	if(multi && multi->callstack.count) {
151	0	size_t i;
152	0	for(i = 0; i < multi->callstack.count; ++i) {
153	0	if(multi->callstack.calls[i] == CURL_CBAPI_FN_multi_ntfy_cb)
154	0	return TRUE;
155	0	}
156	0	}
157	0	return FALSE;
158	0	}
159
160		bool Curl_api_multi_is_in_callback(struct Curl_multi *multi)
161	0	{
162	0	if(multi && multi->callstack.count) {
163	0	size_t i;
164	0	for(i = 0; i < multi->callstack.count; ++i) {
165	0	if(multi->callstack.calls[i] >= CURL_CBAPI_FN_START)
166	0	return TRUE;
167	0	}
168	0	}
169	0	return FALSE;
170	0	}
171
172		bool Curl_api_is_in_callback(struct Curl_easy *data)
173	0	{
174	0	if(data && data->multi) {
175	0	return Curl_api_multi_is_in_callback(data->multi);
176	0	}
177	0	return FALSE;
178	0	}
179
180		bool Curl_eapi_enter(struct Curl_eapi_guard *guard,
181		CURL *curl,
182		Curl_eapi_fn fn,
183		CURLcode *presult)
184	0	{
185	0	struct Curl_easy *data = curl;
186	0	const struct Curl_eapi_fn_props *fn_props;
187	0	CURLcode result = CURLE_OK;
188
189	0	guard->depth = 0;
190
191		/* Verify that we got an easy handle we can work with. */
192	0	if(!GOOD_EASY_HANDLE(data)) {
193	0	result = CURLE_BAD_FUNCTION_ARGUMENT;
194	0	goto out;
195	0	}
196		/* verify that is either not added to a multi handle OR has a
197		* GOOD multi handle that knows `data` for `data->mid`. */
198	0	if(data->mid != UINT32_MAX) {
199	0	if(GOOD_MULTI_HANDLE(data->multi)) {
200	0	if(!Curl_multi_knows_easy(data->multi, data)) {
201		/* But multi does not know it, something is fishy, better deny call */
202	0	DEBUGASSERT(0);
203	0	result = CURLE_BAD_FUNCTION_ARGUMENT;
204	0	goto out;
205	0	}
206	0	}
207	0	else {
208	0	DEBUGASSERT(0); /* data needs to have a GOOD multi handle */
209	0	result = CURLE_BAD_FUNCTION_ARGUMENT;
210	0	goto out;
211	0	}
212	0	}
213	0	else if(data->multi) {
214	0	DEBUGASSERT(0); /* data should not have a multi handle */
215	0	result = CURLE_BAD_FUNCTION_ARGUMENT;
216	0	goto out;
217	0	}
218		/* verify that the call `fn` we're about to enter is known
219		* and check call properties to be admitting. */
220	0	if(fn >= CURL_EAPI_FN_LAST) {
221	0	result = CURLE_BAD_FUNCTION_ARGUMENT;
222	0	goto out;
223	0	}
224	0	fn_props = &eapi_fn_props[fn];
225	0	DEBUGASSERT(fn_props->fn == fn);
226	0	if(!fn_props->recurse) {
227	0	if(data->callstack.count) {
228	0	#ifdef CURLVERBOSE
229	0	DEBUGF(curl_mfprintf(stderr,
230	0	"EAPI guard: calling %hu with call to %u ongoing\n", (uint16_t)fn,
231	0	data->callstack.calls[data->callstack.count-1]));
232	0	#endif
233	0	result = CURLE_RECURSIVE_API_CALL;
234	0	goto out;
235	0	}
236	0	if(data->multi && data->multi->callstack.count) {
237	0	#ifdef CURLVERBOSE
238
239	0	DEBUGF(curl_mfprintf(stderr,
240	0	"EAPI guard: calling %hu with multi call to %u ongoing\n",
241	0	(uint16_t)fn,
242	0	data->multi->callstack.calls[data->multi->callstack.count-1]));
243	0	#endif
244	0	result = CURLE_RECURSIVE_API_CALL;
245	0	goto out;
246	0	}
247	0	}
248
249	0	if(fn_props->no_event_cb && eapi_in_event_cb(data)) {
250		/* Not allowed to be invoked while an event cb is ongoing */
251	0	#ifdef CURLVERBOSE
252	0	DEBUGF(curl_mfprintf(stderr,
253	0	"EAPI guard: calling %hu while event callback ongoing\n",
254	0	(uint16_t)fn));
255	0	#endif
256	0	result = CURLE_RECURSIVE_API_CALL;
257	0	goto out;
258	0	}
259
260	0	#if defined(USE_SSL) && defined(USE_MUTEX)
261	0	if(fn_props->no_scache_lock &&
262	0	Curl_ssl_scache_is_locked_by_current_thread(data)) {
263	0	#ifdef CURLVERBOSE
264	0	DEBUGF(curl_mfprintf(stderr,
265	0	"EAPI guard: calling %hu while vtls_scache is locked by "
266	0	"current thread\n", (uint16_t)fn));
267	0	#endif
268	0	result = CURLE_RECURSIVE_API_CALL;
269	0	goto out;
270	0	}
271	0	#endif
272
273		/* all fine, add to data's callstack */
274	0	if(data->callstack.count >= CURL_EAPI_MAX_RECURSION) {
275	0	result = CURLE_RECURSIVE_API_CALL;
276	0	goto out;
277	0	}
278	0	data->callstack.calls[data->callstack.count] = (uint16_t)fn;
279	0	++data->callstack.count;
280	0	guard->depth = data->callstack.count;
281	0	guard->data = fn_props->data_is_killed ? NULL : data;
282
283	0	out:
284	0	if(presult)
285	0	*presult = result;
286	0	return guard->depth > 0;
287	0	}
288
289		void Curl_eapi_leave(struct Curl_eapi_guard *guard)
290	0	{
291	0	if(guard->depth) {
292		/* guard->data is set when handle is supposed to stay alive during call */
293	0	if(guard->data && GOOD_EASY_HANDLE(guard->data)) {
294	0	if(guard->depth > guard->data->callstack.count) {
295	0	DEBUGASSERT(0); /* something very wrong */
296	0	}
297	0	else {
298	0	if(guard->depth < guard->data->callstack.count) {
299	0	DEBUGASSERT(0); /* someone forgot to clean up */
300	0	}
301		/* reset to depth the guard was entered in */
302	0	guard->data->callstack.count = (uint16_t)(guard->depth - 1);
303	0	}
304	0	}
305	0	}
306	0	}
307
308		CURLHcode Curl_eapi_hcode(CURLcode result)
309	0	{
310	0	switch(result) {
311	0	case CURLE_OK:
312	0	return CURLHE_OK;
313	0	case CURLE_BAD_FUNCTION_ARGUMENT:
314	0	return CURLHE_BAD_ARGUMENT;
315	0	case CURLE_OUT_OF_MEMORY:
316	0	return CURLHE_OUT_OF_MEMORY;
317	0	case CURLE_NOT_BUILT_IN:
318	0	return CURLHE_NOT_BUILT_IN;
319	0	default:
320		/* Unfortunately, we cannot convert RECURSIVE_API_CALL,
321		* but since the header API is reentrant, this should not happen. */
322	0	return CURLHE_BAD_ARGUMENT;
323	0	}
324	0	}
325
326		bool Curl_mapi_enter(struct Curl_mapi_guard *guard,
327		CURLM *m,
328		Curl_mapi_fn fn,
329		CURLMcode *pmresult)
330	0	{
331	0	struct Curl_multi *multi = m;
332	0	const struct Curl_mapi_fn_props *fn_props;
333	0	CURLMcode mresult = CURLM_OK;
334
335	0	guard->depth = 0;
336
337		/* Verify that we got an easy handle we can work with. */
338	0	if(!GOOD_MULTI_HANDLE(multi)) {
339	0	mresult = CURLM_BAD_HANDLE;
340	0	goto out;
341	0	}
342	0	if(fn >= CURL_MAPI_FN_LAST) {
343	0	mresult = CURLM_BAD_FUNCTION_ARGUMENT;
344	0	goto out;
345	0	}
346	0	fn_props = &mapi_fn_props[fn];
347	0	DEBUGASSERT(fn_props->fn == fn);
348	0	if(fn_props->allow_ntfy_cb && mapi_in_ntfy_cb(multi)) {
349		/* explicitly allowed, even though normal recursion may not */
350	0	}
351	0	else if(!fn_props->recurse && multi->callstack.count) {
352	0	#ifdef CURLVERBOSE
353	0	DEBUGF(curl_mfprintf(stderr,
354	0	"MAPI guard: calling %hu with call to %u ongoing\n", (uint16_t)fn,
355	0	multi->callstack.calls[multi->callstack.count-1]));
356	0	#endif
357	0	mresult = CURLM_RECURSIVE_API_CALL;
358	0	goto out;
359	0	}
360
361	0	#if defined(USE_SSL) && defined(USE_MUTEX)
362	0	if(fn_props->no_scache_lock && multi->ssl_scache &&
363	0	Curl_ssl_scache_is_locked_by_current_thread(multi->admin)) {
364	0	#ifdef CURLVERBOSE
365	0	DEBUGF(curl_mfprintf(stderr,
366	0	"MAPI guard: calling %hu while its vtls_scache is locked by "
367	0	"current thread\n", (uint16_t)fn));
368	0	#endif
369	0	mresult = CURLM_RECURSIVE_API_CALL;
370	0	goto out;
371	0	}
372	0	#endif
373
374		/* all fine, add to data's callstack */
375	0	if(multi->callstack.count >= CURL_MAPI_MAX_RECURSION) {
376	0	mresult = CURLM_RECURSIVE_API_CALL;
377	0	goto out;
378	0	}
379	0	multi->callstack.calls[multi->callstack.count] = (uint16_t)fn;
380	0	++multi->callstack.count;
381	0	guard->depth = multi->callstack.count;
382	0	guard->multi = fn_props->multi_is_killed ? NULL : multi;
383
384	0	out:
385	0	if(pmresult)
386	0	*pmresult = mresult;
387	0	return guard->depth > 0;
388	0	}
389
390		void Curl_mapi_leave(struct Curl_mapi_guard *guard)
391	0	{
392	0	if(guard->depth) {
393		/* guard->data is set when handle is supposed to stay alive during call */
394	0	if(guard->multi && GOOD_MULTI_HANDLE(guard->multi)) {
395	0	if(guard->depth > guard->multi->callstack.count) {
396	0	DEBUGASSERT(0); /* something very wrong */
397	0	}
398	0	else {
399	0	if(guard->depth < guard->multi->callstack.count) {
400	0	DEBUGASSERT(0); /* someone forgot to clean up */
401	0	}
402		/* reset to depth the guard was entered in */
403	0	guard->multi->callstack.count = (uint16_t)(guard->depth - 1);
404	0	}
405	0	}
406	0	}
407	0	}
408
409		void Curl_cbapi_enter(struct Curl_mapi_guard *guard,
410		struct Curl_easy *data,
411		struct Curl_multi *multi,
412		Curl_cbapi_fn fn)
413	0	{
414	0	guard->depth = 0;
415
416	0	if(!multi)
417	0	multi = data ? data->multi : NULL;
418		/* if not multi is involved here, just leave */
419	0	if(!multi)
420	0	return;
421		/* invalid callback specifier? */
422	0	if((fn >= CURL_CBAPI_FN_LAST) \|\| (fn < CURL_CBAPI_FN_START)) {
423	0	DEBUGASSERT(0);
424	0	return;
425	0	}
426	0	DEBUGASSERT(cbapi_fn_props[fn - CURL_CBAPI_FN_START].fn == fn);
427	0	if(multi->callstack.count) {
428	0	size_t i;
429	0	for(i = multi->callstack.count; i; --i) {
430	0	if(multi->callstack.calls[i - 1] == fn) {
431		/* recursive invocation of the same callback */
432	0	DEBUGASSERT(0);
433	0	return;
434	0	}
435	0	}
436	0	}
437
438		/* all fine, add to data's callstack */
439		/* if multi callstack already at max depth, leave */
440	0	if(multi->callstack.count >= CURL_MAPI_MAX_RECURSION)
441	0	return;
442	0	multi->callstack.calls[multi->callstack.count] = (uint16_t)fn;
443	0	++multi->callstack.count;
444	0	guard->depth = multi->callstack.count;
445	0	guard->multi = multi;
446	0	}
447
448		void Curl_cbapi_leave(struct Curl_mapi_guard *guard)
449	0	{
450	0	Curl_mapi_leave(guard);
451	0	}