1#include <stdio.h>
2#ifndef LLHTTP__TEST
3# include "llhttp.h"
4#else
5# define llhttp_t llparse_t
6#endif /* */
7
8int llhttp_message_needs_eof(const llhttp_t* parser);
9int llhttp_should_keep_alive(const llhttp_t* parser);
10
11int llhttp__before_headers_complete(llhttp_t* parser, const char* p,
12 const char* endp) {
13 /* Set this here so that on_headers_complete() callbacks can see it */
14 if ((parser->flags & F_UPGRADE) &&
15 (parser->flags & F_CONNECTION_UPGRADE)) {
16 /* For responses, "Upgrade: foo" and "Connection: upgrade" are
17 * mandatory only when it is a 101 Switching Protocols response,
18 * otherwise it is purely informational, to announce support.
19 */
20 parser->upgrade =
21 (parser->type == HTTP_REQUEST || parser->status_code == 101);
22 } else {
23 parser->upgrade = (parser->method == HTTP_CONNECT);
24 }
25 return 0;
26}
27
28
29/* Return values:
30 * 0 - No body, `restart`, message_complete
31 * 1 - CONNECT request, `restart`, message_complete, and pause
32 * 2 - chunk_size_start
33 * 3 - body_identity
34 * 4 - body_identity_eof
35 * 5 - invalid transfer-encoding for request
36 */
37int llhttp__after_headers_complete(llhttp_t* parser, const char* p,
38 const char* endp) {
39 int hasBody;
40
41 hasBody = parser->flags & F_CHUNKED || parser->content_length > 0;
42 if (
43 (parser->upgrade && (parser->method == HTTP_CONNECT ||
44 (parser->flags & F_SKIPBODY) || !hasBody)) ||
45 /* See RFC 2616 section 4.4 - 1xx e.g. Continue */
46 (parser->type == HTTP_RESPONSE && parser->status_code == 101)
47 ) {
48 /* Exit, the rest of the message is in a different protocol. */
49 return 1;
50 }
51
52 if (parser->type == HTTP_RESPONSE && parser->status_code == 100) {
53 /* No body, restart as the message is complete */
54 return 0;
55 }
56
57 /* See RFC 2616 section 4.4 */
58 if (
59 parser->flags & F_SKIPBODY || /* response to a HEAD request */
60 (
61 parser->type == HTTP_RESPONSE && (
62 parser->status_code == 102 || /* Processing */
63 parser->status_code == 103 || /* Early Hints */
64 parser->status_code == 204 || /* No Content */
65 parser->status_code == 304 /* Not Modified */
66 )
67 )
68 ) {
69 return 0;
70 } else if (parser->flags & F_CHUNKED) {
71 /* chunked encoding - ignore Content-Length header, prepare for a chunk */
72 return 2;
73 } else if (parser->flags & F_TRANSFER_ENCODING) {
74 if (parser->type == HTTP_REQUEST &&
75 (parser->lenient_flags & LENIENT_CHUNKED_LENGTH) == 0 &&
76 (parser->lenient_flags & LENIENT_TRANSFER_ENCODING) == 0) {
77 /* RFC 7230 3.3.3 */
78
79 /* If a Transfer-Encoding header field
80 * is present in a request and the chunked transfer coding is not
81 * the final encoding, the message body length cannot be determined
82 * reliably; the server MUST respond with the 400 (Bad Request)
83 * status code and then close the connection.
84 */
85 return 5;
86 } else {
87 /* RFC 7230 3.3.3 */
88
89 /* If a Transfer-Encoding header field is present in a response and
90 * the chunked transfer coding is not the final encoding, the
91 * message body length is determined by reading the connection until
92 * it is closed by the server.
93 */
94 return 4;
95 }
96 } else {
97 if (!(parser->flags & F_CONTENT_LENGTH)) {
98 if (!llhttp_message_needs_eof(parser)) {
99 /* Assume content-length 0 - read the next */
100 return 0;
101 } else {
102 /* Read body until EOF */
103 return 4;
104 }
105 } else if (parser->content_length == 0) {
106 /* Content-Length header given but zero: Content-Length: 0\r\n */
107 return 0;
108 } else {
109 /* Content-Length header given and non-zero */
110 return 3;
111 }
112 }
113}
114
115
116int llhttp__after_message_complete(llhttp_t* parser, const char* p,
117 const char* endp) {
118 int should_keep_alive;
119
120 should_keep_alive = llhttp_should_keep_alive(parser);
121 parser->finish = HTTP_FINISH_SAFE;
122 parser->flags = 0;
123
124 /* NOTE: this is ignored in loose parsing mode */
125 return should_keep_alive;
126}
127
128
129int llhttp_message_needs_eof(const llhttp_t* parser) {
130 if (parser->type == HTTP_REQUEST) {
131 return 0;
132 }
133
134 /* See RFC 2616 section 4.4 */
135 if (parser->status_code / 100 == 1 || /* 1xx e.g. Continue */
136 parser->status_code == 204 || /* No Content */
137 parser->status_code == 304 || /* Not Modified */
138 (parser->flags & F_SKIPBODY)) { /* response to a HEAD request */
139 return 0;
140 }
141
142 /* RFC 7230 3.3.3, see `llhttp__after_headers_complete` */
143 if ((parser->flags & F_TRANSFER_ENCODING) &&
144 (parser->flags & F_CHUNKED) == 0) {
145 return 1;
146 }
147
148 if (parser->flags & (F_CHUNKED | F_CONTENT_LENGTH)) {
149 return 0;
150 }
151
152 return 1;
153}
154
155
156int llhttp_should_keep_alive(const llhttp_t* parser) {
157 if (parser->http_major > 0 && parser->http_minor > 0) {
158 /* HTTP/1.1 */
159 if (parser->flags & F_CONNECTION_CLOSE) {
160 return 0;
161 }
162 } else {
163 /* HTTP/1.0 or earlier */
164 if (!(parser->flags & F_CONNECTION_KEEP_ALIVE)) {
165 return 0;
166 }
167 }
168
169 return !llhttp_message_needs_eof(parser);
170}
171