/*
This file is part of GNUnet
Copyright (C) 2014, 2015, 2016, 2018 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @file curl/curl.c
* @brief API for downloading JSON via CURL
* @author Sree Harsha Totakura
* @author Christian Grothoff
*/
#include "platform.h"
#include
#include
#include "gnunet_curl_lib.h"
#if ENABLE_BENCHMARK
#include "../util/benchmark.h"
#endif
/**
* Log error related to CURL operations.
*
* @param type log level
* @param function which function failed to run
* @param code what was the curl error code
*/
#define CURL_STRERROR(type, function, code) \
GNUNET_log (type, \
"Curl function `%s' has failed at `%s:%d' with error: %s\n", \
function, \
__FILE__, \
__LINE__, \
curl_easy_strerror (code));
/**
* Print JSON parsing related error information
*/
#define JSON_WARN(error) \
GNUNET_log (GNUNET_ERROR_TYPE_WARNING, \
"JSON parsing failed at %s:%u: %s (%s)\n", \
__FILE__, \
__LINE__, \
error.text, \
error.source)
/**
* Failsafe flag. Raised if our constructor fails to initialize
* the Curl library.
*/
static int curl_fail;
/**
* Jobs are CURL requests running within a `struct GNUNET_CURL_Context`.
*/
struct GNUNET_CURL_Job
{
/**
* We keep jobs in a DLL.
*/
struct GNUNET_CURL_Job *next;
/**
* We keep jobs in a DLL.
*/
struct GNUNET_CURL_Job *prev;
/**
* Easy handle of the job.
*/
CURL *easy_handle;
/**
* Context this job runs in.
*/
struct GNUNET_CURL_Context *ctx;
/**
* Function to call upon completion.
*/
GNUNET_CURL_JobCompletionCallback jcc;
/**
* Closure for @e jcc.
*/
void *jcc_cls;
/**
* Function to call upon completion.
*/
GNUNET_CURL_RawJobCompletionCallback jcc_raw;
/**
* Closure for @e jcc_raw.
*/
void *jcc_raw_cls;
/**
* Buffer for response received from CURL.
*/
struct GNUNET_CURL_DownloadBuffer db;
/**
* Headers used for this job, the list needs to be freed
* after the job has finished.
*/
struct curl_slist *job_headers;
};
/**
* Context
*/
struct GNUNET_CURL_Context
{
/**
* Curl multi handle
*/
CURLM *multi;
/**
* Curl share handle
*/
CURLSH *share;
/**
* We keep jobs in a DLL.
*/
struct GNUNET_CURL_Job *jobs_head;
/**
* We keep jobs in a DLL.
*/
struct GNUNET_CURL_Job *jobs_tail;
/**
* Headers common for all requests in the context.
*/
struct curl_slist *common_headers;
/**
* If non-NULL, the async scope ID is sent in a request
* header of this name.
*/
const char *async_scope_id_header;
/**
* Function we need to call whenever the event loop's
* socket set changed.
*/
GNUNET_CURL_RescheduleCallback cb;
/**
* Closure for @e cb.
*/
void *cb_cls;
/**
* USERNAME:PASSWORD to use for client-authentication
* with all requests of this context, or NULL.
*/
char *userpass;
/**
* Type of the TLS client certificate used, or NULL.
*/
char *certtype;
/**
* File with the TLS client certificate, or NULL.
*/
char *certfile;
/**
* File with the private key to authenticate the
* TLS client, or NULL.
*/
char *keyfile;
/**
* Passphrase to decrypt @e keyfile, or NULL.
*/
char *keypass;
};
void
GNUNET_CURL_set_userpass (struct GNUNET_CURL_Context *ctx,
const char *userpass)
{
GNUNET_free (ctx->userpass);
if (NULL != userpass)
ctx->userpass = GNUNET_strdup (userpass);
}
void
GNUNET_CURL_set_tlscert (struct GNUNET_CURL_Context *ctx,
const char *certtype,
const char *certfile,
const char *keyfile,
const char *keypass)
{
GNUNET_free (ctx->certtype);
GNUNET_free (ctx->certfile);
GNUNET_free (ctx->keyfile);
GNUNET_free (ctx->keypass);
if (NULL != certtype)
ctx->certtype = GNUNET_strdup (certtype);
if (NULL != certfile)
ctx->certfile = GNUNET_strdup (certfile);
if (NULL != keyfile)
ctx->certtype = GNUNET_strdup (keyfile);
if (NULL != keypass)
ctx->certtype = GNUNET_strdup (keypass);
}
struct GNUNET_CURL_Context *
GNUNET_CURL_init (GNUNET_CURL_RescheduleCallback cb,
void *cb_cls)
{
struct GNUNET_CURL_Context *ctx;
CURLM *multi;
CURLSH *share;
if (curl_fail)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Curl was not initialised properly\n");
return NULL;
}
if (NULL == (multi = curl_multi_init ()))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to create a Curl multi handle\n");
return NULL;
}
if (NULL == (share = curl_share_init ()))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to create a Curl share handle\n");
return NULL;
}
ctx = GNUNET_new (struct GNUNET_CURL_Context);
ctx->cb = cb;
ctx->cb_cls = cb_cls;
ctx->multi = multi;
ctx->share = share;
return ctx;
}
void
GNUNET_CURL_enable_async_scope_header (struct GNUNET_CURL_Context *ctx,
const char *header_name)
{
ctx->async_scope_id_header = header_name;
}
int
GNUNET_CURL_is_valid_scope_id (const char *scope_id)
{
if (strlen (scope_id) >= 64)
return GNUNET_NO;
for (size_t i = 0; i < strlen (scope_id); i++)
if (! (isalnum (scope_id[i]) || (scope_id[i] == '-')))
return GNUNET_NO;
return GNUNET_YES;
}
/**
* Callback used when downloading the reply to an HTTP request.
* Just appends all of the data to the `buf` in the
* `struct DownloadBuffer` for further processing. The size of
* the download is limited to #GNUNET_MAX_MALLOC_CHECKED, if
* the download exceeds this size, we abort with an error.
*
* @param bufptr data downloaded via HTTP
* @param size size of an item in @a bufptr
* @param nitems number of items in @a bufptr
* @param cls the `struct DownloadBuffer`
* @return number of bytes processed from @a bufptr
*/
static size_t
download_cb (char *bufptr,
size_t size,
size_t nitems,
void *cls)
{
struct GNUNET_CURL_DownloadBuffer *db = cls;
size_t msize;
void *buf;
if (0 == size * nitems)
{
/* Nothing (left) to do */
return 0;
}
msize = size * nitems;
if ((msize + db->buf_size) >= GNUNET_MAX_MALLOC_CHECKED)
{
db->eno = ENOMEM;
return 0; /* signals an error to curl */
}
db->buf = GNUNET_realloc (db->buf,
db->buf_size + msize);
buf = db->buf + db->buf_size;
GNUNET_memcpy (buf, bufptr, msize);
db->buf_size += msize;
return msize;
}
/**
* Create the HTTP headers for the request
*
* @param ctx context we run in
* @param job_headers job-specific headers
* @return all headers to use
*/
static struct curl_slist *
setup_job_headers (struct GNUNET_CURL_Context *ctx,
const struct curl_slist *job_headers)
{
struct curl_slist *all_headers = NULL;
for (const struct curl_slist *curr = job_headers;
NULL != curr;
curr = curr->next)
{
GNUNET_assert (NULL !=
(all_headers = curl_slist_append (all_headers,
curr->data)));
}
for (const struct curl_slist *curr = ctx->common_headers;
NULL != curr;
curr = curr->next)
{
GNUNET_assert (NULL !=
(all_headers = curl_slist_append (all_headers,
curr->data)));
}
if (NULL != ctx->async_scope_id_header)
{
struct GNUNET_AsyncScopeSave scope;
GNUNET_async_scope_get (&scope);
if (GNUNET_YES == scope.have_scope)
{
char *aid_header;
aid_header =
GNUNET_STRINGS_data_to_string_alloc (
&scope.scope_id,
sizeof(struct GNUNET_AsyncScopeId));
GNUNET_assert (NULL != aid_header);
GNUNET_assert (NULL != curl_slist_append (all_headers,
aid_header));
GNUNET_free (aid_header);
}
}
return all_headers;
}
/**
* Create a job.
*
* @param eh easy handle to use
* @param ctx context to run the job in
* @param all_headers HTTP client headers to use (free'd)
* @return NULL on error
*/
static struct GNUNET_CURL_Job *
setup_job (CURL *eh,
struct GNUNET_CURL_Context *ctx,
struct curl_slist *all_headers)
{
struct GNUNET_CURL_Job *job;
if (CURLE_OK !=
curl_easy_setopt (eh,
CURLOPT_HTTPHEADER,
all_headers))
{
GNUNET_break (0);
curl_slist_free_all (all_headers);
curl_easy_cleanup (eh);
return NULL;
}
job = GNUNET_new (struct GNUNET_CURL_Job);
job->job_headers = all_headers;
if ( (CURLE_OK !=
curl_easy_setopt (eh,
CURLOPT_PRIVATE,
job)) ||
(CURLE_OK !=
curl_easy_setopt (eh,
CURLOPT_WRITEFUNCTION,
&download_cb)) ||
(CURLE_OK !=
curl_easy_setopt (eh,
CURLOPT_WRITEDATA,
&job->db)) ||
(CURLE_OK !=
curl_easy_setopt (eh,
CURLOPT_SHARE,
ctx->share)) ||
(CURLM_OK !=
curl_multi_add_handle (ctx->multi,
eh)) )
{
GNUNET_break (0);
GNUNET_free (job);
curl_easy_cleanup (eh);
return NULL;
}
job->easy_handle = eh;
job->ctx = ctx;
GNUNET_CONTAINER_DLL_insert (ctx->jobs_head,
ctx->jobs_tail,
job);
return job;
}
void
GNUNET_CURL_extend_headers (struct GNUNET_CURL_Job *job,
const struct curl_slist *extra_headers)
{
struct curl_slist *all_headers = job->job_headers;
for (const struct curl_slist *curr = extra_headers;
NULL != curr;
curr = curr->next)
{
GNUNET_assert (NULL !=
(all_headers = curl_slist_append (all_headers,
curr->data)));
}
job->job_headers = all_headers;
}
struct GNUNET_CURL_Job *
GNUNET_CURL_job_add_raw (struct GNUNET_CURL_Context *ctx,
CURL *eh,
const struct curl_slist *job_headers,
GNUNET_CURL_RawJobCompletionCallback jcc,
void *jcc_cls)
{
struct GNUNET_CURL_Job *job;
struct curl_slist *all_headers;
GNUNET_assert (NULL != jcc);
all_headers = setup_job_headers (ctx,
job_headers);
if (NULL == (job = setup_job (eh,
ctx,
all_headers)))
return NULL;
job->jcc_raw = jcc;
job->jcc_raw_cls = jcc_cls;
ctx->cb (ctx->cb_cls);
return job;
}
struct GNUNET_CURL_Job *
GNUNET_CURL_job_add2 (struct GNUNET_CURL_Context *ctx,
CURL *eh,
const struct curl_slist *job_headers,
GNUNET_CURL_JobCompletionCallback jcc,
void *jcc_cls)
{
struct GNUNET_CURL_Job *job;
struct curl_slist *all_headers;
GNUNET_assert (NULL != jcc);
if ( (NULL != ctx->userpass) &&
(0 != curl_easy_setopt (eh,
CURLOPT_USERPWD,
ctx->userpass)) )
return NULL;
if ( (NULL != ctx->certfile) &&
(0 != curl_easy_setopt (eh,
CURLOPT_SSLCERT,
ctx->certfile)) )
return NULL;
if ( (NULL != ctx->certtype) &&
(0 != curl_easy_setopt (eh,
CURLOPT_SSLCERTTYPE,
ctx->certtype)) )
return NULL;
if ( (NULL != ctx->keyfile) &&
(0 != curl_easy_setopt (eh,
CURLOPT_SSLKEY,
ctx->keyfile)) )
return NULL;
if ( (NULL != ctx->keypass) &&
(0 != curl_easy_setopt (eh,
CURLOPT_KEYPASSWD,
ctx->keypass)) )
return NULL;
all_headers = setup_job_headers (ctx,
job_headers);
if (NULL == (job = setup_job (eh,
ctx,
all_headers)))
return NULL;
job->jcc = jcc;
job->jcc_cls = jcc_cls;
ctx->cb (ctx->cb_cls);
return job;
}
struct GNUNET_CURL_Job *
GNUNET_CURL_job_add_with_ct_json (struct GNUNET_CURL_Context *ctx,
CURL *eh,
GNUNET_CURL_JobCompletionCallback jcc,
void *jcc_cls)
{
struct GNUNET_CURL_Job *job;
struct curl_slist *job_headers = NULL;
GNUNET_assert (NULL != (job_headers =
curl_slist_append (NULL,
"Content-Type: application/json")));
job = GNUNET_CURL_job_add2 (ctx,
eh,
job_headers,
jcc,
jcc_cls);
curl_slist_free_all (job_headers);
return job;
}
struct GNUNET_CURL_Job *
GNUNET_CURL_job_add (struct GNUNET_CURL_Context *ctx,
CURL *eh,
GNUNET_CURL_JobCompletionCallback jcc,
void *jcc_cls)
{
return GNUNET_CURL_job_add2 (ctx,
eh,
NULL,
jcc,
jcc_cls);
}
void
GNUNET_CURL_job_cancel (struct GNUNET_CURL_Job *job)
{
struct GNUNET_CURL_Context *ctx = job->ctx;
GNUNET_CONTAINER_DLL_remove (ctx->jobs_head,
ctx->jobs_tail,
job);
GNUNET_break (CURLM_OK ==
curl_multi_remove_handle (ctx->multi,
job->easy_handle));
curl_easy_cleanup (job->easy_handle);
GNUNET_free (job->db.buf);
curl_slist_free_all (job->job_headers);
ctx->cb (ctx->cb_cls);
GNUNET_free (job);
}
/**
* Test if the given content type @a ct is JSON
*
* @param ct a content type, e.g. "application/json; charset=UTF-8"
* @return true if @a ct denotes JSON
*/
static bool
is_json (const char *ct)
{
const char *semi;
/* check for "application/json" exact match */
if (0 == strcasecmp (ct,
"application/json"))
return true;
/* check for "application/json;[ANYTHING]" */
semi = strchr (ct,
';');
/* also allow "application/json [ANYTHING]" (note the space!) */
if (NULL == semi)
semi = strchr (ct,
' ');
if (NULL == semi)
return false; /* no delimiter we accept, forget it */
if (semi - ct != strlen ("application/json"))
return false; /* delimiter past desired length, forget it */
if (0 == strncasecmp (ct,
"application/json",
strlen ("application/json")))
return true; /* OK */
return false;
}
void *
GNUNET_CURL_download_get_result_ (struct GNUNET_CURL_DownloadBuffer *db,
CURL *eh,
long *response_code)
{
json_t *json;
json_error_t error;
char *ct;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Downloaded body: %.*s\n",
(int) db->buf_size,
(char *) db->buf);
if (CURLE_OK !=
curl_easy_getinfo (eh,
CURLINFO_RESPONSE_CODE,
response_code))
{
/* unexpected error... */
GNUNET_break (0);
*response_code = 0;
}
if ((CURLE_OK !=
curl_easy_getinfo (eh,
CURLINFO_CONTENT_TYPE,
&ct)) ||
(NULL == ct) ||
(! is_json (ct)))
{
/* No content type or explicitly not JSON, refuse to parse
(but keep response code) */
if (0 != db->buf_size)
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Did NOT detect response `%.*s' as JSON\n",
(int) db->buf_size,
(const char *) db->buf);
return NULL;
}
if (MHD_HTTP_NO_CONTENT == *response_code)
return NULL;
if (0 == *response_code)
{
char *url;
if (CURLE_OK !=
curl_easy_getinfo (eh,
CURLINFO_EFFECTIVE_URL,
&url))
url = "";
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Failed to download response from `%s': \n",
url);
return NULL;
}
json = NULL;
if (0 == db->eno)
{
json = json_loadb (db->buf,
db->buf_size,
JSON_REJECT_DUPLICATES | JSON_DISABLE_EOF_CHECK,
&error);
if (NULL == json)
{
JSON_WARN (error);
*response_code = 0;
}
}
GNUNET_free (db->buf);
db->buf = NULL;
db->buf_size = 0;
return json;
}
enum GNUNET_GenericReturnValue
GNUNET_CURL_append_header (struct GNUNET_CURL_Context *ctx,
const char *header)
{
ctx->common_headers = curl_slist_append (ctx->common_headers,
header);
if (NULL == ctx->common_headers)
return GNUNET_SYSERR;
return GNUNET_OK;
}
void
GNUNET_CURL_perform2 (struct GNUNET_CURL_Context *ctx,
GNUNET_CURL_RawParser rp,
GNUNET_CURL_ResponseCleaner rc)
{
CURLMsg *cmsg;
int n_running;
int n_completed;
(void) curl_multi_perform (ctx->multi,
&n_running);
while (NULL != (cmsg = curl_multi_info_read (ctx->multi,
&n_completed)))
{
struct GNUNET_CURL_Job *job;
long response_code;
void *response;
/* Only documented return value is CURLMSG_DONE */
GNUNET_break (CURLMSG_DONE == cmsg->msg);
GNUNET_assert (CURLE_OK ==
curl_easy_getinfo (cmsg->easy_handle,
CURLINFO_PRIVATE,
(char **) &job));
GNUNET_assert (job->ctx == ctx);
response_code = 0;
if (NULL != job->jcc_raw)
{
/* RAW mode, no parsing */
GNUNET_break (CURLE_OK ==
curl_easy_getinfo (job->easy_handle,
CURLINFO_RESPONSE_CODE,
&response_code));
job->jcc_raw (job->jcc_raw_cls,
response_code,
job->db.buf,
job->db.buf_size);
}
else
{
/* to be parsed via 'rp' */
response = rp (&job->db,
job->easy_handle,
&response_code);
job->jcc (job->jcc_cls,
response_code,
response);
rc (response);
}
GNUNET_CURL_job_cancel (job);
}
}
void
GNUNET_CURL_perform (struct GNUNET_CURL_Context *ctx)
{
GNUNET_CURL_perform2 (ctx,
&GNUNET_CURL_download_get_result_,
(GNUNET_CURL_ResponseCleaner) & json_decref);
}
void
GNUNET_CURL_get_select_info (struct GNUNET_CURL_Context *ctx,
fd_set *read_fd_set,
fd_set *write_fd_set,
fd_set *except_fd_set,
int *max_fd,
long *timeout)
{
long to;
int m;
m = -1;
GNUNET_assert (CURLM_OK ==
curl_multi_fdset (ctx->multi,
read_fd_set,
write_fd_set,
except_fd_set,
&m));
to = *timeout;
*max_fd = GNUNET_MAX (m, *max_fd);
GNUNET_assert (CURLM_OK ==
curl_multi_timeout (ctx->multi,
&to));
/* Only if what we got back from curl is smaller than what we
already had (-1 == infinity!), then update timeout */
if ((to < *timeout) && (-1 != to))
*timeout = to;
if ((-1 == (*timeout)) && (NULL != ctx->jobs_head))
*timeout = to;
}
void
GNUNET_CURL_fini (struct GNUNET_CURL_Context *ctx)
{
/* all jobs must have been cancelled at this time, assert this */
GNUNET_assert (NULL == ctx->jobs_head);
curl_share_cleanup (ctx->share);
curl_multi_cleanup (ctx->multi);
curl_slist_free_all (ctx->common_headers);
GNUNET_free (ctx->userpass);
GNUNET_free (ctx->certtype);
GNUNET_free (ctx->certfile);
GNUNET_free (ctx->keyfile);
GNUNET_free (ctx->keypass);
GNUNET_free (ctx);
}
/**
* Initial global setup logic, specifically runs the Curl setup.
*/
__attribute__ ((constructor)) void
GNUNET_CURL_constructor__ (void)
{
CURLcode ret;
if (CURLE_OK != (ret = curl_global_init (CURL_GLOBAL_DEFAULT)))
{
CURL_STRERROR (GNUNET_ERROR_TYPE_ERROR,
"curl_global_init",
ret);
curl_fail = 1;
}
}
/**
* Cleans up after us, specifically runs the Curl cleanup.
*/
__attribute__ ((destructor)) void
GNUNET_CURL_destructor__ (void)
{
if (curl_fail)
return;
curl_global_cleanup ();
}
/* end of curl.c */