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comparison src/event/quic/ngx_event_quic_transport.c @ 8683:de7b9af30fc6 quic

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QUIC: refactored packet creation. The "min" and "max" arguments refer to UDP datagram size. Generating payload requires to account properly for header size, which is variable and depends on payload size and packet number.
author Vladimir Homutov <vl@nginx.com>
date Thu, 07 Oct 2021 13:48:29 +0300
parents 126a15530136
children cab3b7a070ef
comparison
equal deleted inserted replaced
8682:126a15530136 8683:de7b9af30fc6
92 static ngx_int_t ngx_quic_parse_long_header(ngx_quic_header_t *pkt); 92 static ngx_int_t ngx_quic_parse_long_header(ngx_quic_header_t *pkt);
93 static ngx_int_t ngx_quic_supported_version(uint32_t version); 93 static ngx_int_t ngx_quic_supported_version(uint32_t version);
94 static ngx_int_t ngx_quic_parse_long_header_v1(ngx_quic_header_t *pkt); 94 static ngx_int_t ngx_quic_parse_long_header_v1(ngx_quic_header_t *pkt);
95 95
96 static size_t ngx_quic_create_long_header(ngx_quic_header_t *pkt, u_char *out, 96 static size_t ngx_quic_create_long_header(ngx_quic_header_t *pkt, u_char *out,
97 size_t pkt_len, u_char **pnp); 97 u_char **pnp);
98 static size_t ngx_quic_create_short_header(ngx_quic_header_t *pkt, u_char *out, 98 static size_t ngx_quic_create_short_header(ngx_quic_header_t *pkt, u_char *out,
99 u_char **pnp); 99 u_char **pnp);
100 100
101 static ngx_int_t ngx_quic_frame_allowed(ngx_quic_header_t *pkt, 101 static ngx_int_t ngx_quic_frame_allowed(ngx_quic_header_t *pkt,
102 ngx_uint_t frame_type); 102 ngx_uint_t frame_type);
611 611
612 return p - start; 612 return p - start;
613 } 613 }
614 614
615 615
616 /* returns the amount of payload quic packet of "pkt_len" size may fit or 0 */
616 size_t 617 size_t
617 ngx_quic_create_header(ngx_quic_header_t *pkt, u_char *out, size_t pkt_len, 618 ngx_quic_payload_size(ngx_quic_header_t *pkt, size_t pkt_len)
618 u_char **pnp) 619 {
620 size_t len;
621
622 if ngx_quic_short_pkt(pkt->flags) {
623
624 len = 1 + pkt->dcid.len + pkt->num_len + EVP_GCM_TLS_TAG_LEN;
625 if (len > pkt_len) {
626 return 0;
627 }
628
629 return pkt_len - len;
630 }
631
632 /* flags, version, dcid and scid with lengths and zero-length token */
633 len = 5 + 2 + pkt->dcid.len + pkt->scid.len
634 + (pkt->level == ssl_encryption_initial ? 1 : 0);
635
636 if (len > pkt_len) {
637 return 0;
638 }
639
640 /* (pkt_len - len) is 'remainder' packet length (see RFC 9000, 17.2) */
641 len += ngx_quic_varint_len(pkt_len - len)
642 + pkt->num_len + EVP_GCM_TLS_TAG_LEN;
643
644 if (len > pkt_len) {
645 return 0;
646 }
647
648 return pkt_len - len;
649 }
650
651
652 size_t
653 ngx_quic_create_header(ngx_quic_header_t *pkt, u_char *out, u_char **pnp)
619 { 654 {
620 return ngx_quic_short_pkt(pkt->flags) 655 return ngx_quic_short_pkt(pkt->flags)
621 ? ngx_quic_create_short_header(pkt, out, pnp) 656 ? ngx_quic_create_short_header(pkt, out, pnp)
622 : ngx_quic_create_long_header(pkt, out, pkt_len, pnp); 657 : ngx_quic_create_long_header(pkt, out, pnp);
623 } 658 }
624 659
625 660
626 static size_t 661 static size_t
627 ngx_quic_create_long_header(ngx_quic_header_t *pkt, u_char *out, 662 ngx_quic_create_long_header(ngx_quic_header_t *pkt, u_char *out,
628 size_t pkt_len, u_char **pnp) 663 u_char **pnp)
629 { 664 {
665 size_t rem_len;
630 u_char *p, *start; 666 u_char *p, *start;
667
668 rem_len = pkt->num_len + pkt->payload.len + EVP_GCM_TLS_TAG_LEN;
631 669
632 if (out == NULL) { 670 if (out == NULL) {
633 return 5 + 2 + pkt->dcid.len + pkt->scid.len 671 return 5 + 2 + pkt->dcid.len + pkt->scid.len
634 + ngx_quic_varint_len(pkt_len + pkt->num_len) + pkt->num_len 672 + ngx_quic_varint_len(rem_len) + pkt->num_len
635 + (pkt->level == ssl_encryption_initial ? 1 : 0); 673 + (pkt->level == ssl_encryption_initial ? 1 : 0);
636 } 674 }
637 675
638 p = start = out; 676 p = start = out;
639 677
649 687
650 if (pkt->level == ssl_encryption_initial) { 688 if (pkt->level == ssl_encryption_initial) {
651 ngx_quic_build_int(&p, 0); 689 ngx_quic_build_int(&p, 0);
652 } 690 }
653 691
654 ngx_quic_build_int(&p, pkt_len + pkt->num_len); 692 ngx_quic_build_int(&p, rem_len);
655 693
656 *pnp = p; 694 *pnp = p;
657 695
658 switch (pkt->num_len) { 696 switch (pkt->num_len) {
659 case 1: 697 case 1: