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-rw-r--r--serve.c258
1 files changed, 258 insertions, 0 deletions
diff --git a/serve.c b/serve.c
new file mode 100644
index 0000000000..bda085f09c
--- /dev/null
+++ b/serve.c
@@ -0,0 +1,258 @@
+#include "cache.h"
+#include "repository.h"
+#include "config.h"
+#include "pkt-line.h"
+#include "version.h"
+#include "argv-array.h"
+#include "ls-refs.h"
+#include "serve.h"
+#include "upload-pack.h"
+
+static int always_advertise(struct repository *r,
+ struct strbuf *value)
+{
+ return 1;
+}
+
+static int agent_advertise(struct repository *r,
+ struct strbuf *value)
+{
+ if (value)
+ strbuf_addstr(value, git_user_agent_sanitized());
+ return 1;
+}
+
+struct protocol_capability {
+ /*
+ * The name of the capability. The server uses this name when
+ * advertising this capability, and the client uses this name to
+ * specify this capability.
+ */
+ const char *name;
+
+ /*
+ * Function queried to see if a capability should be advertised.
+ * Optionally a value can be specified by adding it to 'value'.
+ * If a value is added to 'value', the server will advertise this
+ * capability as "<name>=<value>" instead of "<name>".
+ */
+ int (*advertise)(struct repository *r, struct strbuf *value);
+
+ /*
+ * Function called when a client requests the capability as a command.
+ * The function will be provided the capabilities requested via 'keys'
+ * as well as a struct packet_reader 'request' which the command should
+ * use to read the command specific part of the request. Every command
+ * MUST read until a flush packet is seen before sending a response.
+ *
+ * This field should be NULL for capabilities which are not commands.
+ */
+ int (*command)(struct repository *r,
+ struct argv_array *keys,
+ struct packet_reader *request);
+};
+
+static struct protocol_capability capabilities[] = {
+ { "agent", agent_advertise, NULL },
+ { "ls-refs", always_advertise, ls_refs },
+ { "fetch", upload_pack_advertise, upload_pack_v2 },
+ { "server-option", always_advertise, NULL },
+};
+
+static void advertise_capabilities(void)
+{
+ struct strbuf capability = STRBUF_INIT;
+ struct strbuf value = STRBUF_INIT;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
+ struct protocol_capability *c = &capabilities[i];
+
+ if (c->advertise(the_repository, &value)) {
+ strbuf_addstr(&capability, c->name);
+
+ if (value.len) {
+ strbuf_addch(&capability, '=');
+ strbuf_addbuf(&capability, &value);
+ }
+
+ strbuf_addch(&capability, '\n');
+ packet_write(1, capability.buf, capability.len);
+ }
+
+ strbuf_reset(&capability);
+ strbuf_reset(&value);
+ }
+
+ packet_flush(1);
+ strbuf_release(&capability);
+ strbuf_release(&value);
+}
+
+static struct protocol_capability *get_capability(const char *key)
+{
+ int i;
+
+ if (!key)
+ return NULL;
+
+ for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
+ struct protocol_capability *c = &capabilities[i];
+ const char *out;
+ if (skip_prefix(key, c->name, &out) && (!*out || *out == '='))
+ return c;
+ }
+
+ return NULL;
+}
+
+static int is_valid_capability(const char *key)
+{
+ const struct protocol_capability *c = get_capability(key);
+
+ return c && c->advertise(the_repository, NULL);
+}
+
+static int is_command(const char *key, struct protocol_capability **command)
+{
+ const char *out;
+
+ if (skip_prefix(key, "command=", &out)) {
+ struct protocol_capability *cmd = get_capability(out);
+
+ if (*command)
+ die("command '%s' requested after already requesting command '%s'",
+ out, (*command)->name);
+ if (!cmd || !cmd->advertise(the_repository, NULL) || !cmd->command)
+ die("invalid command '%s'", out);
+
+ *command = cmd;
+ return 1;
+ }
+
+ return 0;
+}
+
+int has_capability(const struct argv_array *keys, const char *capability,
+ const char **value)
+{
+ int i;
+ for (i = 0; i < keys->argc; i++) {
+ const char *out;
+ if (skip_prefix(keys->argv[i], capability, &out) &&
+ (!*out || *out == '=')) {
+ if (value) {
+ if (*out == '=')
+ out++;
+ *value = out;
+ }
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+enum request_state {
+ PROCESS_REQUEST_KEYS,
+ PROCESS_REQUEST_DONE,
+};
+
+static int process_request(void)
+{
+ enum request_state state = PROCESS_REQUEST_KEYS;
+ struct packet_reader reader;
+ struct argv_array keys = ARGV_ARRAY_INIT;
+ struct protocol_capability *command = NULL;
+
+ packet_reader_init(&reader, 0, NULL, 0,
+ PACKET_READ_CHOMP_NEWLINE |
+ PACKET_READ_GENTLE_ON_EOF);
+
+ /*
+ * Check to see if the client closed their end before sending another
+ * request. If so we can terminate the connection.
+ */
+ if (packet_reader_peek(&reader) == PACKET_READ_EOF)
+ return 1;
+ reader.options = PACKET_READ_CHOMP_NEWLINE;
+
+ while (state != PROCESS_REQUEST_DONE) {
+ switch (packet_reader_peek(&reader)) {
+ case PACKET_READ_EOF:
+ BUG("Should have already died when seeing EOF");
+ case PACKET_READ_NORMAL:
+ /* collect request; a sequence of keys and values */
+ if (is_command(reader.line, &command) ||
+ is_valid_capability(reader.line))
+ argv_array_push(&keys, reader.line);
+ else
+ die("unknown capability '%s'", reader.line);
+
+ /* Consume the peeked line */
+ packet_reader_read(&reader);
+ break;
+ case PACKET_READ_FLUSH:
+ /*
+ * If no command and no keys were given then the client
+ * wanted to terminate the connection.
+ */
+ if (!keys.argc)
+ return 1;
+
+ /*
+ * The flush packet isn't consume here like it is in
+ * the other parts of this switch statement. This is
+ * so that the command can read the flush packet and
+ * see the end of the request in the same way it would
+ * if command specific arguments were provided after a
+ * delim packet.
+ */
+ state = PROCESS_REQUEST_DONE;
+ break;
+ case PACKET_READ_DELIM:
+ /* Consume the peeked line */
+ packet_reader_read(&reader);
+
+ state = PROCESS_REQUEST_DONE;
+ break;
+ }
+ }
+
+ if (!command)
+ die("no command requested");
+
+ command->command(the_repository, &keys, &reader);
+
+ argv_array_clear(&keys);
+ return 0;
+}
+
+/* Main serve loop for protocol version 2 */
+void serve(struct serve_options *options)
+{
+ if (options->advertise_capabilities || !options->stateless_rpc) {
+ /* serve by default supports v2 */
+ packet_write_fmt(1, "version 2\n");
+
+ advertise_capabilities();
+ /*
+ * If only the list of capabilities was requested exit
+ * immediately after advertising capabilities
+ */
+ if (options->advertise_capabilities)
+ return;
+ }
+
+ /*
+ * If stateless-rpc was requested then exit after
+ * a single request/response exchange
+ */
+ if (options->stateless_rpc) {
+ process_request();
+ } else {
+ for (;;)
+ if (process_request())
+ break;
+ }
+}