Load libcurl with dlopen() on first use instead of a DT_NEEDED entry. More...

#include <curl/curl.h>
#include <dlfcn.h>
#include <pthread.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>

Include dependency graph for curl_dl.cc:

Go to the source code of this file.

Macros
#define	ZYPP_CURL_SONAME "libcurl.so.4"
#define	CURL_DL_HIDDEN __attribute__((visibility("hidden")))
#define	CURL_DL_FN(ret, name, proto, args)
#define	CURL_DL_FN_VOID(name, proto, args)

Functions
	CURL_DL_FN (CURLcode, curl_global_init,(long flags),(flags)) CURL_DL_FN(CURL *
	CURL_DL_FN_VOID (curl_easy_cleanup,(CURL *handle),(handle)) CURL_DL_FN_VOID(curl_easy_reset
CURL handle	CURL_DL_FN (const char *, curl_easy_strerror,(CURLcode code),(code)) CURL_DL_FN_VOID(curl_free
CURL handle void p	CURL_DL_FN (char , curl_unescape,(const char str, int length),(str, length)) CURL_DL_FN(curl_version_info_data *
CURL handle void p CURLversion age	CURL_DL_FN (struct curl_slist , curl_slist_append,(struct curl_slist list, const char *str),(list, str)) CURL_DL_FN_VOID(curl_slist_free_all
CURL handle void p CURLversion age struct curl_slist list	CURL_DL_FN (CURLM *, curl_multi_init,(void),()) CURL_DL_FN(CURLMcode
CURL handle void p CURLversion age struct curl_slist list CURLM multi	CURL_DL_FN (CURLMcode, curl_multi_add_handle,(CURLM multi, CURL handle),(multi, handle)) CURL_DL_FN(CURLMcode
CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle	CURL_DL_FN (CURLMsg , curl_multi_info_read,(CURLM multi, int *msgs_in_queue),(multi, msgs_in_queue)) CURL_DL_FN(CURLMcode
CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int running_handles	CURL_DL_FN (const char , curl_multi_strerror,(CURLMcode code),(code)) CURL_DL_HIDDEN CURLcode curl_easy_getinfo(CURL handle
	if (!fn) (void *) &fn
	va_start (ap, info)
	va_end (ap)
return	fn (handle, info, arg)
CURL_DL_HIDDEN CURLcode	curl_easy_setopt (CURL *handle, CURLoption option,...)
CURL_DL_HIDDEN CURLMcode	curl_multi_setopt (CURLM *multi, CURLMoption option,...)

Variables
	curl_easy_init
	void
CURL *	handle
CURL handle void *	p
CURL handle void p	curl_version_info
CURL handle void p CURLversion	age
CURL handle void p CURLversion age struct curl_slist *	list
CURL handle void p CURLversion age struct curl_slist list	curl_multi_cleanup
CURL handle void p CURLversion age struct curl_slist list CURLM *	multi
CURL handle void p CURLversion age struct curl_slist list CURLM multi	curl_multi_remove_handle
CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle	curl_multi_socket_action
CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t	s
CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int	ev_bitmask
CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int *	running_handles
CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int running_handles CURLINFO	info
CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int running_handles CURLINFO va_list	ap
void *	arg = va_arg( ap, void * )

Detailed Description

Load libcurl with dlopen() on first use instead of a DT_NEEDED entry.

The distro libcurl pulls ~30 shared objects (TLS, ssh, ldap, idn, kerberos, ...) into every process that links it, costing ~2ms of startup per exec - paid even by runs that never touch the network (zypper –help, cached info/search).

This file defines every libcurl symbol libzypp references. Each wrapper resolves the real function from libcurl.so.4 on first call, so the library and its dependency closure are only mapped when a download actually happens. All other code keeps calling plain curl_* functions and stays oblivious.

Keep the list in sync with the real usage: nm -D –undefined-only libzypp.so | grep ' curl_' A missing wrapper resurfaces as a DT_NEEDED on libcurl again (the linker pulls it from CURL_LIBRARIES if someone re-adds it) or as a link error, never as silent misbehavior. A libcurl that cannot be loaded at all, or that lacks one of these symbols, aborts with a message on first use - the same outcome the dynamic loader produced while libcurl was a DT_NEEDED entry, just deferred.

Correctness here depends on libzypp being built with hidden visibility (ENABLE_VISIBILITY_HIDDEN): these definitions must not be exported, or they would interpose libcurl's own intra-library calls.

curl_easy_setopt, curl_multi_setopt and curl_easy_getinfo are variadic in the libcurl ABI. getinfo always takes one pointer; the setopt argument class is defined by the CURLOPTTYPE_* range of the option id, exactly the rule libcurl documents for bindings.

Definition in file curl_dl.cc.

Macro Definition Documentation

◆ ZYPP_CURL_SONAME

#define ZYPP_CURL_SONAME "libcurl.so.4"

Definition at line 54 of file curl_dl.cc.

◆ CURL_DL_HIDDEN

#define CURL_DL_HIDDEN __attribute__((visibility("hidden")))

Definition at line 113 of file curl_dl.cc.

◆ CURL_DL_FN

#define CURL_DL_FN	(	ret,
		name,
		proto,
		args )

Value:

CURL_DL_HIDDEN ret name proto                           \
{                                                       \
  static ret (*fn) proto;                               \
  if ( !fn )                                            \
    *(void **)&fn = curl_dl_sym( #name );               \
  return fn args;                                       \
}

Definition at line 116 of file curl_dl.cc.

◆ CURL_DL_FN_VOID

#define CURL_DL_FN_VOID	(	name,
		proto,
		args )

Value:

CURL_DL_HIDDEN void name proto                          \
{                                                       \
  static void (*fn) proto;                              \
  if ( !fn )                                            \
    *(void **)&fn = curl_dl_sym( #name );               \
  fn args;                                              \
}

Definition at line 126 of file curl_dl.cc.

Function Documentation

◆ CURL_DL_FN() [1/8]

CURL_DL_FN	(	CURLcode	,
		curl_global_init	,
		(long flags)	,
		(flags)	)

◆ CURL_DL_FN_VOID()

CURL_DL_FN_VOID	(	curl_easy_cleanup	,
		(CURL *handle)	,
		(handle)	)

◆ CURL_DL_FN() [2/8]

CURL handle CURL_DL_FN	(	const char *	,
		curl_easy_strerror	,
		(CURLcode code)	,
		(code)	)

◆ CURL_DL_FN() [3/8]

CURL handle void p CURL_DL_FN	(	char *	,
		curl_unescape	,
		(const char *str, int length)	,
		(str, length)	)

◆ CURL_DL_FN() [4/8]

CURL handle void p CURLversion age CURL_DL_FN	(	struct curl_slist *	,
		curl_slist_append	,
		(struct curl_slist list, const char str)	,
		(list, str)	)

◆ CURL_DL_FN() [5/8]

CURL handle void p CURLversion age struct curl_slist list CURL_DL_FN	(	CURLM *	,
		curl_multi_init	,
		(void)	,
		()	)

◆ CURL_DL_FN() [6/8]

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURL_DL_FN	(	CURLMcode	,
		curl_multi_add_handle	,
		(CURLM multi, CURL handle)	,
		(multi, handle)	)

◆ CURL_DL_FN() [7/8]

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURL_DL_FN	(	CURLMsg *	,
		curl_multi_info_read	,
		(CURLM multi, int msgs_in_queue)	,
		(multi, msgs_in_queue)	)

◆ CURL_DL_FN() [8/8]

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int running_handles CURL_DL_FN	(	const char *	,
		curl_multi_strerror	,
		(CURLMcode code)	,
		(code)	)

◆ if()

if ( ! fn ) &

◆ va_start()

va_start	(	ap	,
		info	)

◆ va_end()

va_end ( ap )

◆ fn()

return fn	(	handle	,
		info	,
		arg	)

◆ curl_easy_setopt()

CURL_DL_HIDDEN CURLcode curl_easy_setopt	(	CURL *	handle,
		CURLoption	option,
			... )

Definition at line 173 of file curl_dl.cc.

◆ curl_multi_setopt()

CURL_DL_HIDDEN CURLMcode curl_multi_setopt	(	CURLM *	multi,
		CURLMoption	option,
			... )

Definition at line 193 of file curl_dl.cc.

Variable Documentation

◆ curl_easy_init

curl_easy_init

Definition at line 137 of file curl_dl.cc.

◆ void

void

Definition at line 137 of file curl_dl.cc.

◆ handle

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL * handle

Definition at line 139 of file curl_dl.cc.

◆ p

CURL handle void* p

Definition at line 142 of file curl_dl.cc.

◆ curl_version_info

CURL handle void p curl_version_info

Definition at line 144 of file curl_dl.cc.

◆ age

CURL handle void p CURLversion age

Definition at line 144 of file curl_dl.cc.

◆ list

CURL handle void p CURLversion age struct curl_slist* list

Definition at line 147 of file curl_dl.cc.

◆ curl_multi_cleanup

CURL handle void p CURLversion age struct curl_slist list curl_multi_cleanup

Definition at line 150 of file curl_dl.cc.

◆ multi

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int multi

Definition at line 150 of file curl_dl.cc.

◆ curl_multi_remove_handle

CURL handle void p CURLversion age struct curl_slist list CURLM multi curl_multi_remove_handle

Definition at line 152 of file curl_dl.cc.

◆ curl_multi_socket_action

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle curl_multi_socket_action

Definition at line 154 of file curl_dl.cc.

◆ s

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int s

Definition at line 154 of file curl_dl.cc.

◆ ev_bitmask

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int ev_bitmask

Definition at line 154 of file curl_dl.cc.

◆ running_handles

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int* running_handles

Definition at line 154 of file curl_dl.cc.

◆ info

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int running_handles CURLINFO info

Definition at line 160 of file curl_dl.cc.

◆ ap

CURL handle void p CURLversion age struct curl_slist list CURLM multi CURLM CURL handle CURLM curl_socket_t int int running_handles CURLINFO va_list ap

Initial value:

{

static CURLcode (*fn)( CURL *, CURLINFO, ... )

Definition at line 163 of file curl_dl.cc.

◆ arg

arg = va_arg( ap, void * )

Definition at line 164 of file curl_dl.cc.

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ ZYPP_CURL_SONAME

◆ CURL_DL_HIDDEN

◆ CURL_DL_FN

◆ CURL_DL_FN_VOID

Function Documentation

◆ CURL_DL_FN() [1/8]

◆ CURL_DL_FN_VOID()

◆ CURL_DL_FN() [2/8]

◆ CURL_DL_FN() [3/8]

◆ CURL_DL_FN() [4/8]

◆ CURL_DL_FN() [5/8]

◆ CURL_DL_FN() [6/8]

◆ CURL_DL_FN() [7/8]

◆ CURL_DL_FN() [8/8]

◆ if()

◆ va_start()

◆ va_end()

◆ fn()

◆ curl_easy_setopt()

◆ curl_multi_setopt()

Variable Documentation

◆ curl_easy_init

◆ void

◆ handle

◆ p

◆ curl_version_info

◆ age

◆ list

◆ curl_multi_cleanup

◆ multi

◆ curl_multi_remove_handle

◆ curl_multi_socket_action

◆ s

◆ ev_bitmask

◆ running_handles

◆ info

◆ ap

◆ arg