Mercurial > hg > nginx
view src/http/v3/ngx_http_v3_encode.c @ 8808:5b0c229ba5fe quic
QUIC: fixed padding calculation.
Sometimes, QUIC packets need to be of certain (or minimal) size. This is
achieved by adding PADDING frames. It is possible, that adding padding will
affect header size, thus forcing us to recalculate padding size once more.
author | Vladimir Homutov <vl@nginx.com> |
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date | Mon, 05 Jul 2021 13:17:10 +0300 |
parents | 0ac25efb2da3 |
children | b5a305db30e0 |
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> uintptr_t ngx_http_v3_encode_varlen_int(u_char *p, uint64_t value) { if (value <= 63) { if (p == NULL) { return 1; } *p++ = value; return (uintptr_t) p; } if (value <= 16383) { if (p == NULL) { return 2; } *p++ = 0x40 | (value >> 8); *p++ = value; return (uintptr_t) p; } if (value <= 1073741823) { if (p == NULL) { return 4; } *p++ = 0x80 | (value >> 24); *p++ = (value >> 16); *p++ = (value >> 8); *p++ = value; return (uintptr_t) p; } if (p == NULL) { return 8; } *p++ = 0xc0 | (value >> 56); *p++ = (value >> 48); *p++ = (value >> 40); *p++ = (value >> 32); *p++ = (value >> 24); *p++ = (value >> 16); *p++ = (value >> 8); *p++ = value; return (uintptr_t) p; } uintptr_t ngx_http_v3_encode_prefix_int(u_char *p, uint64_t value, ngx_uint_t prefix) { ngx_uint_t thresh, n; thresh = (1 << prefix) - 1; if (value < thresh) { if (p == NULL) { return 1; } *p++ |= value; return (uintptr_t) p; } value -= thresh; if (p == NULL) { for (n = 2; value >= 128; n++) { value >>= 7; } return n; } *p++ |= thresh; while (value >= 128) { *p++ = 0x80 | value; value >>= 7; } *p++ = value; return (uintptr_t) p; } uintptr_t ngx_http_v3_encode_field_section_prefix(u_char *p, ngx_uint_t insert_count, ngx_uint_t sign, ngx_uint_t delta_base) { if (p == NULL) { return ngx_http_v3_encode_prefix_int(NULL, insert_count, 8) + ngx_http_v3_encode_prefix_int(NULL, delta_base, 7); } *p = 0; p = (u_char *) ngx_http_v3_encode_prefix_int(p, insert_count, 8); *p = sign ? 0x80 : 0; p = (u_char *) ngx_http_v3_encode_prefix_int(p, delta_base, 7); return (uintptr_t) p; } uintptr_t ngx_http_v3_encode_field_ri(u_char *p, ngx_uint_t dynamic, ngx_uint_t index) { /* Indexed Field Line */ if (p == NULL) { return ngx_http_v3_encode_prefix_int(NULL, index, 6); } *p = dynamic ? 0x80 : 0xc0; return ngx_http_v3_encode_prefix_int(p, index, 6); } uintptr_t ngx_http_v3_encode_field_lri(u_char *p, ngx_uint_t dynamic, ngx_uint_t index, u_char *data, size_t len) { /* Literal Field Line With Name Reference */ if (p == NULL) { return ngx_http_v3_encode_prefix_int(NULL, index, 4) + ngx_http_v3_encode_prefix_int(NULL, len, 7) + len; } *p = dynamic ? 0x40 : 0x50; p = (u_char *) ngx_http_v3_encode_prefix_int(p, index, 4); *p = 0; p = (u_char *) ngx_http_v3_encode_prefix_int(p, len, 7); if (data) { p = ngx_cpymem(p, data, len); } return (uintptr_t) p; } uintptr_t ngx_http_v3_encode_field_l(u_char *p, ngx_str_t *name, ngx_str_t *value) { /* Literal Field Line With Literal Name */ if (p == NULL) { return ngx_http_v3_encode_prefix_int(NULL, name->len, 3) + name->len + ngx_http_v3_encode_prefix_int(NULL, value->len, 7) + value->len; } *p = 0x20; p = (u_char *) ngx_http_v3_encode_prefix_int(p, name->len, 3); ngx_strlow(p, name->data, name->len); p += name->len; *p = 0; p = (u_char *) ngx_http_v3_encode_prefix_int(p, value->len, 7); p = ngx_cpymem(p, value->data, value->len); return (uintptr_t) p; } uintptr_t ngx_http_v3_encode_field_pbi(u_char *p, ngx_uint_t index) { /* Indexed Field Line With Post-Base Index */ if (p == NULL) { return ngx_http_v3_encode_prefix_int(NULL, index, 4); } *p = 0x10; return ngx_http_v3_encode_prefix_int(p, index, 4); } uintptr_t ngx_http_v3_encode_field_lpbi(u_char *p, ngx_uint_t index, u_char *data, size_t len) { /* Literal Field Line With Post-Base Name Reference */ if (p == NULL) { return ngx_http_v3_encode_prefix_int(NULL, index, 3) + ngx_http_v3_encode_prefix_int(NULL, len, 7) + len; } *p = 0; p = (u_char *) ngx_http_v3_encode_prefix_int(p, index, 3); *p = 0; p = (u_char *) ngx_http_v3_encode_prefix_int(p, len, 7); if (data) { p = ngx_cpymem(p, data, len); } return (uintptr_t) p; }