gopherproxy-c

Gopher HTTP proxy in C (CGI)
git clone git://git.codemadness.org/gopherproxy-c
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README (3782B)

      1 gopherproxy
      2 ===========
      3 
      4 Build dependencies
      5 ------------------
      6 
      7 - C compiler.
      8 - libc + some BSD extensions (dprintf).
      9 - POSIX system.
     10 - make (optional).
     11 - LibreSSL libtls for gophers:// support (optional).
     12 
     13 
     14 Features
     15 --------
     16 
     17 - Works in older browsers such as links, lynx, w3m, dillo, etc.
     18 - No Javascript or CSS required.
     19 - Gopher+ is not supported.
     20 - Support for Gopher over TLS encryption (gophers://).
     21 
     22 
     23 Cons
     24 ----
     25 
     26 - Not all gopher types are supported.
     27 
     28 
     29 Gopher over TLS
     30 ---------------
     31 
     32 For a description of the protocol see near the section "TLS support":
     33 gopher://bitreich.org/1/scm/gopher-protocol/file/gopher-extension.md.gph
     34 
     35 For a server implementation see:
     36 - geomyidae: gopher://bitreich.org/1/scm/geomyidae
     37 
     38 For client implementations that support it see:
     39 
     40 - cURL: https://curl.se/
     41 - sacc: gopher://bitreich.org/1/scm/sacc
     42 - hurl: gopher://codemadness.org/1/git/hurl
     43 
     44 
     45 CGI configuration examples
     46 --------------------------
     47 
     48 Nginx + slowcgi:
     49 
     50 	location /gopherproxy/ {
     51 		include /etc/nginx/fastcgi_params;
     52 		fastcgi_pass unix:/run/slowcgi.sock;
     53 		fastcgi_param SCRIPT_FILENAME /cgi-bin/gopherproxy.cgi;
     54 		fastcgi_param SCRIPT_NAME     /cgi-bin/gopherproxy.cgi;
     55 		fastcgi_param REQUEST_URI     /cgi-bin/gopherproxy.cgi;
     56 	}
     57 
     58 
     59 OpenBSD httpd + slowcgi:
     60 
     61 	location "/gopherproxy" {
     62 		root "/cgi-bin/gopherproxy.cgi"
     63 		fastcgi
     64 	}
     65 
     66 Caddy + http.cgi:
     67 
     68 	proxy.domain.tld {
     69 		cgi /proxy /usr/local/bin/gopherproxy
     70 	}
     71 
     72 
     73 Notes
     74 -----
     75 
     76 Restrictions:
     77 
     78 For security reasons, only port 70 and 7070 are accepted as valid gopher ports.
     79 Furthermore there is a connection time limit and download size limit. See the
     80 source-code for more information.
     81 
     82 
     83 Tor support:
     84 
     85 Modify the isblacklisted() function in gopherproxy.c to allow .onion addresses.
     86 
     87 
     88 torsocks support:
     89 
     90 To accept torsocks with gopherproxy, remove the -static flag from LDFLAGS in
     91 the Makefile. This is because torsocks is a shared library and "hooks into" the
     92 network calls.
     93 
     94 
     95 Nginx buffering issues:
     96 
     97 When using nginx 1.12+ with OpenBSD slowcgi there may be buffering issues. This
     98 is a bug in nginx. This bug is fixed in newer nginx versions (see patch below).
     99 
    100 Workaround:
    101 	# workaround fastcgi buffering bug in nginx (fixed in 1.14).
    102 	fastcgi_buffering off;
    103 
    104 Patch:
    105 
    106 commit cfc8c28259b3fd59f2517ac4830a08e8a9925148
    107 Author: Maxim Dounin <mdounin@mdounin.ru>
    108 Date:   Thu Nov 9 15:35:20 2017 +0300
    109 
    110     FastCGI: adjust buffer position when parsing incomplete records.
    111     
    112     Previously, nginx failed to move buffer position when parsing an incomplete
    113     record header, and due to this wasn't be able to continue parsing once
    114     remaining bytes of the record header were received.
    115     
    116     This can affect response header parsing, potentially generating spurious errors
    117     like "upstream sent unexpected FastCGI request id high byte: 1 while reading
    118     response header from upstream".  While this is very unlikely, since usually
    119     record headers are written in a single buffer, this still can happen in real
    120     life, for example, if a record header will be split across two TCP packets
    121     and the second packet will be delayed.
    122     
    123     This does not affect non-buffered response body proxying, due to "buf->pos =
    124     buf->last;" at the start of the ngx_http_fastcgi_non_buffered_filter()
    125     function.  Also this does not affect buffered response body proxying, as
    126     each input buffer is only passed to the filter once.
    127 
    128 diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
    129 index ea16ecae..b4bb1d0a 100644
    130 --- a/src/http/modules/ngx_http_fastcgi_module.c
    131 +++ b/src/http/modules/ngx_http_fastcgi_module.c
    132 @@ -2646,6 +2646,7 @@ ngx_http_fastcgi_process_record(ngx_http_request_t *r,
    133          }
    134      }
    135  
    136 +    f->pos = p;
    137      f->state = state;
    138  
    139      return NGX_AGAIN;