Range filter: protect from total size overflows. The overflow can be used to circumvent the restriction on total size of ranges introduced in c2a91088b0c0 (1.1.2). Additionally, overflow allows producing ranges with negative start (such ranges can be created by using a suffix, "bytes=-100"; normally this results in 200 due to the total size check). These can result in the following errors in logs: [crit] ... pread() ... failed (22: Invalid argument) [alert] ... sendfile() failed (22: Invalid argument) When using cache, it can be also used to reveal cache file header. It is believed that there are no other negative effects, at least with standard nginx modules. In theory, this can also result in memory disclosure and/or segmentation faults if multiple ranges are allowed, and the response is returned in a single in-memory buffer. This never happens with standard nginx modules though, as well as known 3rd party modules. Fix is to properly protect from possible overflow when incrementing size.

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


NGX_MAKEFILE=$NGX_OBJS/Makefile
NGX_MODULES_C=$NGX_OBJS/ngx_modules.c

NGX_AUTO_HEADERS_H=$NGX_OBJS/ngx_auto_headers.h
NGX_AUTO_CONFIG_H=$NGX_OBJS/ngx_auto_config.h

NGX_AUTOTEST=$NGX_OBJS/autotest
NGX_AUTOCONF_ERR=$NGX_OBJS/autoconf.err

# STUBs
NGX_ERR=$NGX_OBJS/autoconf.err
MAKEFILE=$NGX_OBJS/Makefile


NGX_PCH=
NGX_USE_PCH=


# check the echo's "-n" option and "\c" capability

if echo "test\c" | grep c >/dev/null; then

    if echo -n test | grep n >/dev/null; then
        ngx_n=
        ngx_c=

    else
        ngx_n=-n
        ngx_c=
    fi

else
    ngx_n=
    ngx_c='\c'
fi


# create Makefile

cat << END > Makefile

default:	build

clean:
	rm -rf Makefile $NGX_OBJS
END