Merge branch 'ss/get-time-cleanup'
[git/git.git] / serve.c
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"
10
11 static int always_advertise(struct repository *r,
12 struct strbuf *value)
13 {
14 return 1;
15 }
16
17 static int agent_advertise(struct repository *r,
18 struct strbuf *value)
19 {
20 if (value)
21 strbuf_addstr(value, git_user_agent_sanitized());
22 return 1;
23 }
24
25 struct protocol_capability {
26 /*
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.
30 */
31 const char *name;
32
33 /*
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>".
38 */
39 int (*advertise)(struct repository *r, struct strbuf *value);
40
41 /*
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.
47 *
48 * This field should be NULL for capabilities which are not commands.
49 */
50 int (*command)(struct repository *r,
51 struct argv_array *keys,
52 struct packet_reader *request);
53 };
54
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 },
60 };
61
62 static void advertise_capabilities(void)
63 {
64 struct strbuf capability = STRBUF_INIT;
65 struct strbuf value = STRBUF_INIT;
66 int i;
67
68 for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
69 struct protocol_capability *c = &capabilities[i];
70
71 if (c->advertise(the_repository, &value)) {
72 strbuf_addstr(&capability, c->name);
73
74 if (value.len) {
75 strbuf_addch(&capability, '=');
76 strbuf_addbuf(&capability, &value);
77 }
78
79 strbuf_addch(&capability, '\n');
80 packet_write(1, capability.buf, capability.len);
81 }
82
83 strbuf_reset(&capability);
84 strbuf_reset(&value);
85 }
86
87 packet_flush(1);
88 strbuf_release(&capability);
89 strbuf_release(&value);
90 }
91
92 static struct protocol_capability *get_capability(const char *key)
93 {
94 int i;
95
96 if (!key)
97 return NULL;
98
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;
104 }
105
106 return NULL;
107 }
108
109 static int is_valid_capability(const char *key)
110 {
111 const struct protocol_capability *c = get_capability(key);
112
113 return c && c->advertise(the_repository, NULL);
114 }
115
116 static int is_command(const char *key, struct protocol_capability **command)
117 {
118 const char *out;
119
120 if (skip_prefix(key, "command=", &out)) {
121 struct protocol_capability *cmd = get_capability(out);
122
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);
128
129 *command = cmd;
130 return 1;
131 }
132
133 return 0;
134 }
135
136 int has_capability(const struct argv_array *keys, const char *capability,
137 const char **value)
138 {
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;
148 }
149 return 1;
150 }
151 }
152
153 return 0;
154 }
155
156 enum request_state {
157 PROCESS_REQUEST_KEYS,
158 PROCESS_REQUEST_DONE,
159 };
160
161 static int process_request(void)
162 {
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;
167
168 packet_reader_init(&reader, 0, NULL, 0,
169 PACKET_READ_CHOMP_NEWLINE |
170 PACKET_READ_GENTLE_ON_EOF |
171 PACKET_READ_DIE_ON_ERR_PACKET);
172
173 /*
174 * Check to see if the client closed their end before sending another
175 * request. If so we can terminate the connection.
176 */
177 if (packet_reader_peek(&reader) == PACKET_READ_EOF)
178 return 1;
179 reader.options &= ~PACKET_READ_GENTLE_ON_EOF;
180
181 while (state != PROCESS_REQUEST_DONE) {
182 switch (packet_reader_peek(&reader)) {
183 case PACKET_READ_EOF:
184 BUG("Should have already died when seeing EOF");
185 case PACKET_READ_NORMAL:
186 /* collect request; a sequence of keys and values */
187 if (is_command(reader.line, &command) ||
188 is_valid_capability(reader.line))
189 argv_array_push(&keys, reader.line);
190 else
191 die("unknown capability '%s'", reader.line);
192
193 /* Consume the peeked line */
194 packet_reader_read(&reader);
195 break;
196 case PACKET_READ_FLUSH:
197 /*
198 * If no command and no keys were given then the client
199 * wanted to terminate the connection.
200 */
201 if (!keys.argc)
202 return 1;
203
204 /*
205 * The flush packet isn't consume here like it is in
206 * the other parts of this switch statement. This is
207 * so that the command can read the flush packet and
208 * see the end of the request in the same way it would
209 * if command specific arguments were provided after a
210 * delim packet.
211 */
212 state = PROCESS_REQUEST_DONE;
213 break;
214 case PACKET_READ_DELIM:
215 /* Consume the peeked line */
216 packet_reader_read(&reader);
217
218 state = PROCESS_REQUEST_DONE;
219 break;
220 }
221 }
222
223 if (!command)
224 die("no command requested");
225
226 command->command(the_repository, &keys, &reader);
227
228 argv_array_clear(&keys);
229 return 0;
230 }
231
232 /* Main serve loop for protocol version 2 */
233 void serve(struct serve_options *options)
234 {
235 if (options->advertise_capabilities || !options->stateless_rpc) {
236 /* serve by default supports v2 */
237 packet_write_fmt(1, "version 2\n");
238
239 advertise_capabilities();
240 /*
241 * If only the list of capabilities was requested exit
242 * immediately after advertising capabilities
243 */
244 if (options->advertise_capabilities)
245 return;
246 }
247
248 /*
249 * If stateless-rpc was requested then exit after
250 * a single request/response exchange
251 */
252 if (options->stateless_rpc) {
253 process_request();
254 } else {
255 for (;;)
256 if (process_request())
257 break;
258 }
259 }