transport-helper: drop read/write errno checks
[git.git] / serve.c
blobbda085f09c8e10314c2c497dbca978fd9241e7b5
1 #include "cache.h"
2 #include "repository.h"
3 #include "config.h"
4 #include "pkt-line.h"
5 #include "version.h"
6 #include "argv-array.h"
7 #include "ls-refs.h"
8 #include "serve.h"
9 #include "upload-pack.h"
11 static int always_advertise(struct repository *r,
12 struct strbuf *value)
14 return 1;
17 static int agent_advertise(struct repository *r,
18 struct strbuf *value)
20 if (value)
21 strbuf_addstr(value, git_user_agent_sanitized());
22 return 1;
25 struct protocol_capability {
27 * The name of the capability. The server uses this name when
28 * advertising this capability, and the client uses this name to
29 * specify this capability.
31 const char *name;
34 * Function queried to see if a capability should be advertised.
35 * Optionally a value can be specified by adding it to 'value'.
36 * If a value is added to 'value', the server will advertise this
37 * capability as "<name>=<value>" instead of "<name>".
39 int (*advertise)(struct repository *r, struct strbuf *value);
42 * Function called when a client requests the capability as a command.
43 * The function will be provided the capabilities requested via 'keys'
44 * as well as a struct packet_reader 'request' which the command should
45 * use to read the command specific part of the request. Every command
46 * MUST read until a flush packet is seen before sending a response.
48 * This field should be NULL for capabilities which are not commands.
50 int (*command)(struct repository *r,
51 struct argv_array *keys,
52 struct packet_reader *request);
55 static struct protocol_capability capabilities[] = {
56 { "agent", agent_advertise, NULL },
57 { "ls-refs", always_advertise, ls_refs },
58 { "fetch", upload_pack_advertise, upload_pack_v2 },
59 { "server-option", always_advertise, NULL },
62 static void advertise_capabilities(void)
64 struct strbuf capability = STRBUF_INIT;
65 struct strbuf value = STRBUF_INIT;
66 int i;
68 for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
69 struct protocol_capability *c = &capabilities[i];
71 if (c->advertise(the_repository, &value)) {
72 strbuf_addstr(&capability, c->name);
74 if (value.len) {
75 strbuf_addch(&capability, '=');
76 strbuf_addbuf(&capability, &value);
79 strbuf_addch(&capability, '\n');
80 packet_write(1, capability.buf, capability.len);
83 strbuf_reset(&capability);
84 strbuf_reset(&value);
87 packet_flush(1);
88 strbuf_release(&capability);
89 strbuf_release(&value);
92 static struct protocol_capability *get_capability(const char *key)
94 int i;
96 if (!key)
97 return NULL;
99 for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
100 struct protocol_capability *c = &capabilities[i];
101 const char *out;
102 if (skip_prefix(key, c->name, &out) && (!*out || *out == '='))
103 return c;
106 return NULL;
109 static int is_valid_capability(const char *key)
111 const struct protocol_capability *c = get_capability(key);
113 return c && c->advertise(the_repository, NULL);
116 static int is_command(const char *key, struct protocol_capability **command)
118 const char *out;
120 if (skip_prefix(key, "command=", &out)) {
121 struct protocol_capability *cmd = get_capability(out);
123 if (*command)
124 die("command '%s' requested after already requesting command '%s'",
125 out, (*command)->name);
126 if (!cmd || !cmd->advertise(the_repository, NULL) || !cmd->command)
127 die("invalid command '%s'", out);
129 *command = cmd;
130 return 1;
133 return 0;
136 int has_capability(const struct argv_array *keys, const char *capability,
137 const char **value)
139 int i;
140 for (i = 0; i < keys->argc; i++) {
141 const char *out;
142 if (skip_prefix(keys->argv[i], capability, &out) &&
143 (!*out || *out == '=')) {
144 if (value) {
145 if (*out == '=')
146 out++;
147 *value = out;
149 return 1;
153 return 0;
156 enum request_state {
157 PROCESS_REQUEST_KEYS,
158 PROCESS_REQUEST_DONE,
161 static int process_request(void)
163 enum request_state state = PROCESS_REQUEST_KEYS;
164 struct packet_reader reader;
165 struct argv_array keys = ARGV_ARRAY_INIT;
166 struct protocol_capability *command = NULL;
168 packet_reader_init(&reader, 0, NULL, 0,
169 PACKET_READ_CHOMP_NEWLINE |
170 PACKET_READ_GENTLE_ON_EOF);
173 * Check to see if the client closed their end before sending another
174 * request. If so we can terminate the connection.
176 if (packet_reader_peek(&reader) == PACKET_READ_EOF)
177 return 1;
178 reader.options = PACKET_READ_CHOMP_NEWLINE;
180 while (state != PROCESS_REQUEST_DONE) {
181 switch (packet_reader_peek(&reader)) {
182 case PACKET_READ_EOF:
183 BUG("Should have already died when seeing EOF");
184 case PACKET_READ_NORMAL:
185 /* collect request; a sequence of keys and values */
186 if (is_command(reader.line, &command) ||
187 is_valid_capability(reader.line))
188 argv_array_push(&keys, reader.line);
189 else
190 die("unknown capability '%s'", reader.line);
192 /* Consume the peeked line */
193 packet_reader_read(&reader);
194 break;
195 case PACKET_READ_FLUSH:
197 * If no command and no keys were given then the client
198 * wanted to terminate the connection.
200 if (!keys.argc)
201 return 1;
204 * The flush packet isn't consume here like it is in
205 * the other parts of this switch statement. This is
206 * so that the command can read the flush packet and
207 * see the end of the request in the same way it would
208 * if command specific arguments were provided after a
209 * delim packet.
211 state = PROCESS_REQUEST_DONE;
212 break;
213 case PACKET_READ_DELIM:
214 /* Consume the peeked line */
215 packet_reader_read(&reader);
217 state = PROCESS_REQUEST_DONE;
218 break;
222 if (!command)
223 die("no command requested");
225 command->command(the_repository, &keys, &reader);
227 argv_array_clear(&keys);
228 return 0;
231 /* Main serve loop for protocol version 2 */
232 void serve(struct serve_options *options)
234 if (options->advertise_capabilities || !options->stateless_rpc) {
235 /* serve by default supports v2 */
236 packet_write_fmt(1, "version 2\n");
238 advertise_capabilities();
240 * If only the list of capabilities was requested exit
241 * immediately after advertising capabilities
243 if (options->advertise_capabilities)
244 return;
248 * If stateless-rpc was requested then exit after
249 * a single request/response exchange
251 if (options->stateless_rpc) {
252 process_request();
253 } else {
254 for (;;)
255 if (process_request())
256 break;