Fix #76675 - Leave a reference to the resource in the curl handle

[pmmaga]

Link for bugsnet: https://bugs.php.net/bug.php?id=76675

curl_write and curl_write_header expect the curl handle to have the reference to their resource set. Currently, the handles returned by _php_server_push_callback miss them.

[nikic]

I'm getting a segfault when running the added test case:

#0  Curl_init_do (data=data@entry=0x555556b52920, conn=conn@entry=0x0) at url.c:4702
#1  0x00007ffff700c50a in Curl_multi_add_perform (multi=<optimized out>, 
    data=data@entry=0x555556b52920, conn=conn@entry=0x555556a71950) at multi.c:1130
#2  0x00007ffff7025268 in push_promise (frame=0x555556b45518, conn=0x555556a71950, 
    data=0x555556a68260) at http2.c:486
#3  on_frame_recv (session=0x555556b45380, frame=0x555556b45518, userp=0x555556a71950)
    at http2.c:621
#4  0x00007ffff5f85de9 in nghttp2_session_mem_recv ()
   from /usr/lib/x86_64-linux-gnu/libnghttp2.so.14
#5  0x00007ffff7026086 in http2_recv (conn=0x555556a71950, sockindex=<optimized out>, 
    mem=0x555556a6d550 "", len=<optimized out>, err=0x7fffffff9f34) at http2.c:1581
#6  0x00007ffff6ff038d in Curl_read (conn=conn@entry=0x555556a71950, sockfd=3, 
    buf=0x555556a6d550 "", sizerequested=16384, n=n@entry=0x7fffffff9fe0) at sendf.c:741
#7  0x00007ffff7002669 in readwrite_data (comeback=0x7fffffffa06b, done=0x7fffffffa069, 
    didwhat=<synthetic pointer>, k=0x555556a68320, conn=0x555556a71950, data=0x555556a68260)
    at transfer.c:475
#8  Curl_readwrite (conn=0x555556a71950, data=data@entry=0x555556a68260, 
    done=done@entry=0x7fffffffa069, comeback=comeback@entry=0x7fffffffa06b) at transfer.c:1118
#9  0x00007ffff700ce9b in multi_runsingle (multi=multi@entry=0x555556a56a70, now=..., 
    data=data@entry=0x555556a68260) at multi.c:1871
#10 0x00007ffff700e3f4 in curl_multi_perform (multi=0x555556a56a70, running_handles=0x7fffffffa230)
    at multi.c:2136
#11 0x00005555558d8595 in zif_curl_multi_exec (execute_data=0x7fffeea1e2e0, 
    return_value=0x7fffeea1e200) at /home/nikic/php-7.2/ext/curl/multi.c:297

[pmmaga]

I'm not being able to reproduce the segfault. Can you tell me the versions of curl and nghttp2 you have installed?

[nikic]

@pmmaga This is my curl --version output:

curl 7.58.0 (x86_64-pc-linux-gnu) libcurl/7.58.0 OpenSSL/1.1.0g zlib/1.2.11 libidn2/2.0.4 libpsl/0.19.1 (+libidn2/2.0.4) nghttp2/1.30.0 librtmp/2.3
Release-Date: 2018-01-24
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtmp rtsp smb smbs smtp smtps telnet tftp 
Features: AsynchDNS IDN IPv6 Largefile GSS-API Kerberos SPNEGO NTLM NTLM_WB SSL libz TLS-SRP HTTP2 UnixSockets HTTPS-proxy PSL 

[pmmaga]

@nikic The segfault seems caused by curl itself, upgrading it to >=7.61 should fix the issue.

[nikic]

Merged as 32ae716. I've added a SKIPIF for curl < 7.61.

[nicolas-grekas]

Thank you @pmmaga and @nikic!

[Nyholm]

Hm.. I created a docker image and complied PHP to test this PR. However, I failed to make it work... In fact, I failed to make any curl requests..

When I base my image on alpine:3.4 I get curl version 7.60.0 and I can make normal curl requests as expected.

When I base my image on apline:3.6 I get curl version 7.61.1. I cannot reproduce the output of the test in this PR nor can I make any normal curl request...

➜  docker run -it --rm --name foo -v "$PWD":/usr/src/myapp -w /usr/src/myapp php-latest-34 php test3744.php   
Curl Version: 474112
Curl Version: 7.60.0

➜  docker run -it --rm --name foo -v "$PWD":/usr/src/myapp -w /usr/src/myapp php-latest-34 php simple-curl.php 

Output: 56507%                                                                                                                                                                               

➜  docker run -it --rm --name foo -v "$PWD":/usr/src/myapp -w /usr/src/myapp php-latest-36 php test3744.php   
Curl Version: 474369
Curl Version: 7.61.1

➜  docker run -it --rm --name foo -v "$PWD":/usr/src/myapp -w /usr/src/myapp php-latest-36 php simple-curl.php

See https://github.com/Nyholm/php-test-server-push

It is likely that I'm doing something very wrong, but I just wanted to report my findings (or incompetence) =)

[pmmaga]

Hi @Nyholm. For curl to support http2 it needs to be built with libnghttp2. This seems to be the case on alpine >=3.8. Based on the dockerfile of your repo, switching the base image to alpine:3.8 (and replacing openssl-dev with libressl-dev due to conflicts), I managed to run the 3 examples successfully.

[Nyholm]

Ah, Okey, thank you.

How can I, from a PHP library, figure out if the current runtime has http2 support or not? I know I can check PHP and curl version but how do I check if it is built with libnghttp2?

[nicolas-grekas]

Would that do it?: if (CURL_VERSION_HTTP2 & curl_version()['features'])

[nicolas-grekas]

Actually, there is another bug here: if I add $callback = null; just after curl_multi_setopt($mh, CURLMOPT_PUSHFUNCTION, $callback); in the test file, things go bad.