Mercurial > hg > nginx
view src/http/v2/ngx_http_v2_encode.c @ 7851:aa5f8825f24d
Resolver: fixed label types handling in ngx_resolver_copy().
Previously, anything with any of the two high bits set were interpreted
as compression pointers. This is incorrect, as RFC 1035 clearly states
that "The 10 and 01 combinations are reserved for future use". Further,
the 01 combination is actually allocated for EDNS extended label type
(see RFC 2671 and RFC 6891), not really used though.
Fix is to reject unrecognized label types rather than misinterpreting
them as compression pointers.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 25 May 2021 15:17:41 +0300 |
parents | 87e9e4aabf1b |
children | 336084ff943b |
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/* * Copyright (C) Nginx, Inc. * Copyright (C) Valentin V. Bartenev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> static u_char *ngx_http_v2_write_int(u_char *pos, ngx_uint_t prefix, ngx_uint_t value); u_char * ngx_http_v2_string_encode(u_char *dst, u_char *src, size_t len, u_char *tmp, ngx_uint_t lower) { size_t hlen; hlen = ngx_http_v2_huff_encode(src, len, tmp, lower); if (hlen > 0) { *dst = NGX_HTTP_V2_ENCODE_HUFF; dst = ngx_http_v2_write_int(dst, ngx_http_v2_prefix(7), hlen); return ngx_cpymem(dst, tmp, hlen); } *dst = NGX_HTTP_V2_ENCODE_RAW; dst = ngx_http_v2_write_int(dst, ngx_http_v2_prefix(7), len); if (lower) { ngx_strlow(dst, src, len); return dst + len; } return ngx_cpymem(dst, src, len); } static u_char * ngx_http_v2_write_int(u_char *pos, ngx_uint_t prefix, ngx_uint_t value) { if (value < prefix) { *pos++ |= value; return pos; } *pos++ |= prefix; value -= prefix; while (value >= 128) { *pos++ = value % 128 + 128; value /= 128; } *pos++ = (u_char) value; return pos; }