| #include "cache.h" |
| #include "repository.h" |
| #include "config.h" |
| #include "pkt-line.h" |
| #include "version.h" |
| #include "strvec.h" |
| #include "ls-refs.h" |
| #include "serve.h" |
| #include "upload-pack.h" |
| |
| static int advertise_sid; |
| |
| 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; |
| } |
| |
| static int object_format_advertise(struct repository *r, |
| struct strbuf *value) |
| { |
| if (value) |
| strbuf_addstr(value, r->hash_algo->name); |
| return 1; |
| } |
| |
| static int session_id_advertise(struct repository *r, struct strbuf *value) |
| { |
| if (!advertise_sid) |
| return 0; |
| if (value) |
| strbuf_addstr(value, trace2_session_id()); |
| 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 strvec *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 }, |
| { "object-format", object_format_advertise, NULL }, |
| { "session-id", session_id_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 strvec *keys, const char *capability, |
| const char **value) |
| { |
| int i; |
| for (i = 0; i < keys->nr; i++) { |
| const char *out; |
| if (skip_prefix(keys->v[i], capability, &out) && |
| (!*out || *out == '=')) { |
| if (value) { |
| if (*out == '=') |
| out++; |
| *value = out; |
| } |
| return 1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static void check_algorithm(struct repository *r, struct strvec *keys) |
| { |
| int client = GIT_HASH_SHA1, server = hash_algo_by_ptr(r->hash_algo); |
| const char *algo_name; |
| |
| if (has_capability(keys, "object-format", &algo_name)) { |
| client = hash_algo_by_name(algo_name); |
| if (client == GIT_HASH_UNKNOWN) |
| die("unknown object format '%s'", algo_name); |
| } |
| |
| if (client != server) |
| die("mismatched object format: server %s; client %s\n", |
| r->hash_algo->name, hash_algos[client].name); |
| } |
| |
| 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 strvec keys = STRVEC_INIT; |
| struct protocol_capability *command = NULL; |
| const char *client_sid; |
| |
| packet_reader_init(&reader, 0, NULL, 0, |
| PACKET_READ_CHOMP_NEWLINE | |
| PACKET_READ_GENTLE_ON_EOF | |
| PACKET_READ_DIE_ON_ERR_PACKET); |
| |
| /* |
| * 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_GENTLE_ON_EOF; |
| |
| 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)) |
| strvec_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.nr) |
| 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; |
| case PACKET_READ_RESPONSE_END: |
| BUG("unexpected stateless separator packet"); |
| } |
| } |
| |
| if (!command) |
| die("no command requested"); |
| |
| check_algorithm(the_repository, &keys); |
| |
| if (has_capability(&keys, "session-id", &client_sid)) |
| trace2_data_string("transfer", NULL, "client-sid", client_sid); |
| |
| command->command(the_repository, &keys, &reader); |
| |
| strvec_clear(&keys); |
| return 0; |
| } |
| |
| /* Main serve loop for protocol version 2 */ |
| void serve(struct serve_options *options) |
| { |
| git_config_get_bool("transfer.advertisesid", &advertise_sid); |
| |
| 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; |
| } |
| } |