Mercurial > hg > nginx
view src/http/v3/ngx_http_v3_encode.c @ 9208:2ed3f57dca0a
QUIC: fixed unsent MTU probe acknowledgement.
Previously if an MTU probe send failed early in ngx_quic_frame_sendto()
due to allocation error or congestion control, the application level packet
number was not increased, but was still saved as MTU probe packet number.
Later when a packet with this number was acknowledged, the unsent MTU probe
was acknowledged as well. This could result in discovering a bigger MTU than
supported by the path, which could lead to EMSGSIZE (Message too long) errors
while sending further packets.
The problem existed since PMTUD was introduced in 58afcd72446f (1.25.2).
Back then only the unlikely memory allocation error could trigger it. However
in efcdaa66df2e congestion control was added to ngx_quic_frame_sendto() which
can now trigger the issue with a higher probability.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Wed, 14 Feb 2024 16:56:28 +0400 |
parents | 5c86189a1c1b |
children |
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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) { size_t hlen; u_char *p1, *p2; /* 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); p1 = p; *p = 0; p = (u_char *) ngx_http_v3_encode_prefix_int(p, len, 7); if (data) { p2 = p; hlen = ngx_http_huff_encode(data, len, p, 0); if (hlen) { p = p1; *p = 0x80; p = (u_char *) ngx_http_v3_encode_prefix_int(p, hlen, 7); if (p != p2) { ngx_memmove(p, p2, hlen); } p += hlen; } else { 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) { size_t hlen; u_char *p1, *p2; /* 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; } p1 = p; *p = 0x20; p = (u_char *) ngx_http_v3_encode_prefix_int(p, name->len, 3); p2 = p; hlen = ngx_http_huff_encode(name->data, name->len, p, 1); if (hlen) { p = p1; *p = 0x28; p = (u_char *) ngx_http_v3_encode_prefix_int(p, hlen, 3); if (p != p2) { ngx_memmove(p, p2, hlen); } p += hlen; } else { ngx_strlow(p, name->data, name->len); p += name->len; } p1 = p; *p = 0; p = (u_char *) ngx_http_v3_encode_prefix_int(p, value->len, 7); p2 = p; hlen = ngx_http_huff_encode(value->data, value->len, p, 0); if (hlen) { p = p1; *p = 0x80; p = (u_char *) ngx_http_v3_encode_prefix_int(p, hlen, 7); if (p != p2) { ngx_memmove(p, p2, hlen); } p += hlen; } else { 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) { size_t hlen; u_char *p1, *p2; /* 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); p1 = p; *p = 0; p = (u_char *) ngx_http_v3_encode_prefix_int(p, len, 7); if (data) { p2 = p; hlen = ngx_http_huff_encode(data, len, p, 0); if (hlen) { p = p1; *p = 0x80; p = (u_char *) ngx_http_v3_encode_prefix_int(p, hlen, 7); if (p != p2) { ngx_memmove(p, p2, hlen); } p += hlen; } else { p = ngx_cpymem(p, data, len); } } return (uintptr_t) p; }