[sr-dev] [PATCH 1/1] websocket: remove libunistring dependency

[Daniel-Constantin Mierla]

Hello,

getting rid of libunistring is good, indeed, thanks.

One thing that has to be cared with the websocket module is the need to 
link against libssl, so if the new included code is gpl we need to have 
an exception for it to comply with official debian packaging requirements.

The page lists a different license than gpl, it seems to be MIT, which I 
guess is all fine, being compatible with GPL and allowing linking with 
libssl. But I wanted to highlight in case anyone else has different 
opinion/more details.

Cheers,
Daniel


On 20/12/13 11:47, Timo Teräs wrote:
> libunistring is old, slow, messy code and uncompilable on new systems.
> remove the sole user of it, and replace it with inline utf8 decoder
> implementation from http://bjoern.hoehrmann.de/utf-8/decoder/dfa/.
>
> improves performance and portability as libunistring is not needed.
> ---
> @Peter, Hugh: Would it be ok for me to push this?
>
>   modules/websocket/Makefile                |  2 +-
>   modules/websocket/README                  |  1 -
>   modules/websocket/doc/websocket_admin.xml |  3 --
>   modules/websocket/utf8_decode.h           | 52 +++++++++++++++++++++++++++++++
>   modules/websocket/ws_frame.c              |  4 +--
>   5 files changed, 55 insertions(+), 7 deletions(-)
>   create mode 100644 modules/websocket/utf8_decode.h
>
> diff --git a/modules/websocket/Makefile b/modules/websocket/Makefile
> index bb7c809..c686a82 100644
> --- a/modules/websocket/Makefile
> +++ b/modules/websocket/Makefile
> @@ -27,7 +27,7 @@ else
>   	#       E.g.: make TLS_HOOKS=1 TLS_EXTRA_LIBS="-lz -lkrb5"
>   endif
>   
> -LIBS+= $(TLS_EXTRA_LIBS) -lunistring
> +LIBS+= $(TLS_EXTRA_LIBS)
>   
>   # Static linking, if you'd like to use TLS and WEBSOCKET at the same time
>   #
> diff --git a/modules/websocket/README b/modules/websocket/README
> index 49d8693..bdba3e4 100644
> --- a/modules/websocket/README
> +++ b/modules/websocket/README
> @@ -316,7 +316,6 @@ onreply_route[WS_REPLY] {
>      The following libraries must be installed before running Kamailio with
>      this module loaded:
>        * OpenSSL.
> -     * GNU libunistring.
>   
>   4. Parameters
>   
> diff --git a/modules/websocket/doc/websocket_admin.xml b/modules/websocket/doc/websocket_admin.xml
> index fa7d300..e40dc09 100644
> --- a/modules/websocket/doc/websocket_admin.xml
> +++ b/modules/websocket/doc/websocket_admin.xml
> @@ -262,9 +262,6 @@ onreply_route[WS_REPLY] {
>   		<listitem>
>   		<para><emphasis>OpenSSL</emphasis>.</para>
>   		</listitem>
> -		<listitem>
> -		<para><emphasis>GNU libunistring</emphasis>.</para>
> -		</listitem>
>   		</itemizedlist>
>   		</para>
>   	</section>
> diff --git a/modules/websocket/utf8_decode.h b/modules/websocket/utf8_decode.h
> new file mode 100644
> index 0000000..b274fe7
> --- /dev/null
> +++ b/modules/websocket/utf8_decode.h
> @@ -0,0 +1,52 @@
> +#include <stdint.h>
> +#include <stddef.h>
> +
> +// Copyright (c) 2008-2010 Bjoern Hoehrmann <bjoern at hoehrmann.de>
> +// See http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ for details.
> +
> +#define UTF8_ACCEPT 0
> +#define UTF8_REJECT 12
> +
> +static const uint8_t utf8d[] = {
> +  // The first part of the table maps bytes to character classes that
> +  // to reduce the size of the transition table and create bitmasks.
> +   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
> +   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
> +   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
> +   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
> +   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
> +   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,  7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
> +   8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2,  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
> +  10,3,3,3,3,3,3,3,3,3,3,3,3,4,3,3, 11,6,6,6,5,8,8,8,8,8,8,8,8,8,8,8,
> +
> +  // The second part is a transition table that maps a combination
> +  // of a state of the automaton and a character class to a state.
> +   0,12,24,36,60,96,84,12,12,12,48,72, 12,12,12,12,12,12,12,12,12,12,12,12,
> +  12, 0,12,12,12,12,12, 0,12, 0,12,12, 12,24,12,12,12,12,12,24,12,24,12,12,
> +  12,12,12,12,12,12,12,24,12,12,12,12, 12,24,12,12,12,12,12,12,12,24,12,12,
> +  12,12,12,12,12,12,12,36,12,36,12,12, 12,36,12,12,12,12,12,36,12,36,12,12,
> +  12,36,12,12,12,12,12,12,12,12,12,12,
> +};
> +
> +static inline uint32_t decode(uint32_t* state, uint32_t* codep, uint32_t byte)
> +{
> +  uint32_t type = utf8d[byte];
> +
> +  *codep = (*state != UTF8_ACCEPT) ?
> +    (byte & 0x3fu) | (*codep << 6) :
> +    (0xff >> type) & (byte);
> +
> +  *state = utf8d[256 + *state + type];
> +  return *state;
> +}
> +
> +static inline int IsUTF8(uint8_t* s, size_t len)
> +{
> +  uint32_t codepoint, state = 0;
> +
> +  while (len--)
> +    decode(&state, &codepoint, *s++);
> +
> +  return state == UTF8_ACCEPT;
> +}
> +
> diff --git a/modules/websocket/ws_frame.c b/modules/websocket/ws_frame.c
> index a3a4cef..3562437 100644
> --- a/modules/websocket/ws_frame.c
> +++ b/modules/websocket/ws_frame.c
> @@ -22,7 +22,7 @@
>    */
>   
>   #include <limits.h>
> -#include <unistr.h>
> +#include "utf8_decode.h"
>   #include "../../events.h"
>   #include "../../receive.h"
>   #include "../../stats.h"
> @@ -695,7 +695,7 @@ int ws_frame_transmit(void *data)
>   	frame.fin = 1;
>   	/* Can't be sure whether this message is UTF-8 or not so check to see
>   	   if it "might" be UTF-8 and send as binary if it definitely isn't */
> -	frame.opcode = (u8_check((uint8_t *) wsev->buf, wsev->len) == NULL) ?
> +	frame.opcode = IsUTF8((uint8_t *) wsev->buf, wsev->len) ?
>   				OPCODE_TEXT_FRAME : OPCODE_BINARY_FRAME;
>   	frame.payload_len = wsev->len;
>   	frame.payload_data = wsev->buf;


-- 
Daniel-Constantin Mierla - http://www.asipto.com
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda