Merge branch 'ah/misc-doc-updates'
[gitweb.git] / connect.c
index c3a014c5babf72ee4c0d135fec264afb37b040de..31aa9c843311b4e0b01e7378a85709083b071311 100644 (file)
--- a/connect.c
+++ b/connect.c
 #include "sha1-array.h"
 #include "transport.h"
 #include "strbuf.h"
+#include "version.h"
 #include "protocol.h"
 
-static char *server_capabilities;
+static char *server_capabilities_v1;
+static struct argv_array server_capabilities_v2 = ARGV_ARRAY_INIT;
 static const char *parse_feature_value(const char *, const char *, int *);
 
 static int check_ref(const char *name, unsigned int flags)
@@ -46,8 +48,14 @@ int check_ref_type(const struct ref *ref, int flags)
        return check_ref(ref->name, flags);
 }
 
-static void die_initial_contact(int unexpected)
+static NORETURN void die_initial_contact(int unexpected)
 {
+       /*
+        * A hang-up after seeing some response from the other end
+        * means that it is unexpected, as we know the other end is
+        * willing to talk to us.  A hang-up before seeing any
+        * response does not necessarily mean an ACL problem, though.
+        */
        if (unexpected)
                die(_("The remote end hung up upon initial contact"));
        else
@@ -56,6 +64,92 @@ static void die_initial_contact(int unexpected)
                      "and the repository exists."));
 }
 
+/* Checks if the server supports the capability 'c' */
+int server_supports_v2(const char *c, int die_on_error)
+{
+       int i;
+
+       for (i = 0; i < server_capabilities_v2.argc; i++) {
+               const char *out;
+               if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
+                   (!*out || *out == '='))
+                       return 1;
+       }
+
+       if (die_on_error)
+               die("server doesn't support '%s'", c);
+
+       return 0;
+}
+
+int server_supports_feature(const char *c, const char *feature,
+                           int die_on_error)
+{
+       int i;
+
+       for (i = 0; i < server_capabilities_v2.argc; i++) {
+               const char *out;
+               if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
+                   (!*out || *(out++) == '=')) {
+                       if (parse_feature_request(out, feature))
+                               return 1;
+                       else
+                               break;
+               }
+       }
+
+       if (die_on_error)
+               die("server doesn't support feature '%s'", feature);
+
+       return 0;
+}
+
+static void process_capabilities_v2(struct packet_reader *reader)
+{
+       while (packet_reader_read(reader) == PACKET_READ_NORMAL)
+               argv_array_push(&server_capabilities_v2, reader->line);
+
+       if (reader->status != PACKET_READ_FLUSH)
+               die("expected flush after capabilities");
+}
+
+enum protocol_version discover_version(struct packet_reader *reader)
+{
+       enum protocol_version version = protocol_unknown_version;
+
+       /*
+        * Peek the first line of the server's response to
+        * determine the protocol version the server is speaking.
+        */
+       switch (packet_reader_peek(reader)) {
+       case PACKET_READ_EOF:
+               die_initial_contact(0);
+       case PACKET_READ_FLUSH:
+       case PACKET_READ_DELIM:
+               version = protocol_v0;
+               break;
+       case PACKET_READ_NORMAL:
+               version = determine_protocol_version_client(reader->line);
+               break;
+       }
+
+       switch (version) {
+       case protocol_v2:
+               process_capabilities_v2(reader);
+               break;
+       case protocol_v1:
+               /* Read the peeked version line */
+               packet_reader_read(reader);
+               break;
+       case protocol_v0:
+               break;
+       case protocol_unknown_version:
+               BUG("unknown protocol version");
+       }
+
+       return version;
+}
+
 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
 {
        char *sym, *target;
@@ -85,7 +179,7 @@ static void parse_one_symref_info(struct string_list *symref, const char *val, i
 static void annotate_refs_with_symref_info(struct ref *ref)
 {
        struct string_list symref = STRING_LIST_INIT_DUP;
-       const char *feature_list = server_capabilities;
+       const char *feature_list = server_capabilities_v1;
 
        while (feature_list) {
                int len;
@@ -109,60 +203,21 @@ static void annotate_refs_with_symref_info(struct ref *ref)
        string_list_clear(&symref, 0);
 }
 
-/*
- * Read one line of a server's ref advertisement into packet_buffer.
- */
-static int read_remote_ref(int in, char **src_buf, size_t *src_len,
-                          int *responded)
-{
-       int len = packet_read(in, src_buf, src_len,
-                             packet_buffer, sizeof(packet_buffer),
-                             PACKET_READ_GENTLE_ON_EOF |
-                             PACKET_READ_CHOMP_NEWLINE);
-       const char *arg;
-       if (len < 0)
-               die_initial_contact(*responded);
-       if (len > 4 && skip_prefix(packet_buffer, "ERR ", &arg))
-               die("remote error: %s", arg);
-
-       *responded = 1;
-
-       return len;
-}
-
-#define EXPECTING_PROTOCOL_VERSION 0
-#define EXPECTING_FIRST_REF 1
-#define EXPECTING_REF 2
-#define EXPECTING_SHALLOW 3
-
-/* Returns 1 if packet_buffer is a protocol version pkt-line, 0 otherwise. */
-static int process_protocol_version(void)
+static void process_capabilities(const char *line, int *len)
 {
-       switch (determine_protocol_version_client(packet_buffer)) {
-       case protocol_v1:
-               return 1;
-       case protocol_v0:
-               return 0;
-       default:
-               die("server is speaking an unknown protocol");
-       }
-}
-
-static void process_capabilities(int *len)
-{
-       int nul_location = strlen(packet_buffer);
+       int nul_location = strlen(line);
        if (nul_location == *len)
                return;
-       server_capabilities = xstrdup(packet_buffer + nul_location + 1);
+       server_capabilities_v1 = xstrdup(line + nul_location + 1);
        *len = nul_location;
 }
 
-static int process_dummy_ref(void)
+static int process_dummy_ref(const char *line)
 {
        struct object_id oid;
        const char *name;
 
-       if (parse_oid_hex(packet_buffer, &oid, &name))
+       if (parse_oid_hex(line, &oid, &name))
                return 0;
        if (*name != ' ')
                return 0;
@@ -171,20 +226,20 @@ static int process_dummy_ref(void)
        return !oidcmp(&null_oid, &oid) && !strcmp(name, "capabilities^{}");
 }
 
-static void check_no_capabilities(int len)
+static void check_no_capabilities(const char *line, int len)
 {
-       if (strlen(packet_buffer) != len)
+       if (strlen(line) != len)
                warning("Ignoring capabilities after first line '%s'",
-                       packet_buffer + strlen(packet_buffer));
+                       line + strlen(line));
 }
 
-static int process_ref(int len, struct ref ***list, unsigned int flags,
-                      struct oid_array *extra_have)
+static int process_ref(const char *line, int len, struct ref ***list,
+                      unsigned int flags, struct oid_array *extra_have)
 {
        struct object_id old_oid;
        const char *name;
 
-       if (parse_oid_hex(packet_buffer, &old_oid, &name))
+       if (parse_oid_hex(line, &old_oid, &name))
                return 0;
        if (*name != ' ')
                return 0;
@@ -200,16 +255,17 @@ static int process_ref(int len, struct ref ***list, unsigned int flags,
                **list = ref;
                *list = &ref->next;
        }
-       check_no_capabilities(len);
+       check_no_capabilities(line, len);
        return 1;
 }
 
-static int process_shallow(int len, struct oid_array *shallow_points)
+static int process_shallow(const char *line, int len,
+                          struct oid_array *shallow_points)
 {
        const char *arg;
        struct object_id old_oid;
 
-       if (!skip_prefix(packet_buffer, "shallow ", &arg))
+       if (!skip_prefix(line, "shallow ", &arg))
                return 0;
 
        if (get_oid_hex(arg, &old_oid))
@@ -217,60 +273,68 @@ static int process_shallow(int len, struct oid_array *shallow_points)
        if (!shallow_points)
                die("repository on the other end cannot be shallow");
        oid_array_append(shallow_points, &old_oid);
-       check_no_capabilities(len);
+       check_no_capabilities(line, len);
        return 1;
 }
 
+enum get_remote_heads_state {
+       EXPECTING_FIRST_REF = 0,
+       EXPECTING_REF,
+       EXPECTING_SHALLOW,
+       EXPECTING_DONE,
+};
+
 /*
  * Read all the refs from the other end
  */
-struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+struct ref **get_remote_heads(struct packet_reader *reader,
                              struct ref **list, unsigned int flags,
                              struct oid_array *extra_have,
                              struct oid_array *shallow_points)
 {
        struct ref **orig_list = list;
-
-       /*
-        * A hang-up after seeing some response from the other end
-        * means that it is unexpected, as we know the other end is
-        * willing to talk to us.  A hang-up before seeing any
-        * response does not necessarily mean an ACL problem, though.
-        */
-       int responded = 0;
-       int len;
-       int state = EXPECTING_PROTOCOL_VERSION;
+       int len = 0;
+       enum get_remote_heads_state state = EXPECTING_FIRST_REF;
+       const char *arg;
 
        *list = NULL;
 
-       while ((len = read_remote_ref(in, &src_buf, &src_len, &responded))) {
+       while (state != EXPECTING_DONE) {
+               switch (packet_reader_read(reader)) {
+               case PACKET_READ_EOF:
+                       die_initial_contact(1);
+               case PACKET_READ_NORMAL:
+                       len = reader->pktlen;
+                       if (len > 4 && skip_prefix(reader->line, "ERR ", &arg))
+                               die("remote error: %s", arg);
+                       break;
+               case PACKET_READ_FLUSH:
+                       state = EXPECTING_DONE;
+                       break;
+               case PACKET_READ_DELIM:
+                       die("invalid packet");
+               }
+
                switch (state) {
-               case EXPECTING_PROTOCOL_VERSION:
-                       if (process_protocol_version()) {
-                               state = EXPECTING_FIRST_REF;
-                               break;
-                       }
-                       state = EXPECTING_FIRST_REF;
-                       /* fallthrough */
                case EXPECTING_FIRST_REF:
-                       process_capabilities(&len);
-                       if (process_dummy_ref()) {
+                       process_capabilities(reader->line, &len);
+                       if (process_dummy_ref(reader->line)) {
                                state = EXPECTING_SHALLOW;
                                break;
                        }
                        state = EXPECTING_REF;
                        /* fallthrough */
                case EXPECTING_REF:
-                       if (process_ref(len, &list, flags, extra_have))
+                       if (process_ref(reader->line, len, &list, flags, extra_have))
                                break;
                        state = EXPECTING_SHALLOW;
                        /* fallthrough */
                case EXPECTING_SHALLOW:
-                       if (process_shallow(len, shallow_points))
+                       if (process_shallow(reader->line, len, shallow_points))
                                break;
-                       die("protocol error: unexpected '%s'", packet_buffer);
-               default:
-                       die("unexpected state %d", state);
+                       die("protocol error: unexpected '%s'", reader->line);
+               case EXPECTING_DONE:
+                       break;
                }
        }
 
@@ -279,6 +343,112 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
        return list;
 }
 
+/* Returns 1 when a valid ref has been added to `list`, 0 otherwise */
+static int process_ref_v2(const char *line, struct ref ***list)
+{
+       int ret = 1;
+       int i = 0;
+       struct object_id old_oid;
+       struct ref *ref;
+       struct string_list line_sections = STRING_LIST_INIT_DUP;
+       const char *end;
+
+       /*
+        * Ref lines have a number of fields which are space deliminated.  The
+        * first field is the OID of the ref.  The second field is the ref
+        * name.  Subsequent fields (symref-target and peeled) are optional and
+        * don't have a particular order.
+        */
+       if (string_list_split(&line_sections, line, ' ', -1) < 2) {
+               ret = 0;
+               goto out;
+       }
+
+       if (parse_oid_hex(line_sections.items[i++].string, &old_oid, &end) ||
+           *end) {
+               ret = 0;
+               goto out;
+       }
+
+       ref = alloc_ref(line_sections.items[i++].string);
+
+       oidcpy(&ref->old_oid, &old_oid);
+       **list = ref;
+       *list = &ref->next;
+
+       for (; i < line_sections.nr; i++) {
+               const char *arg = line_sections.items[i].string;
+               if (skip_prefix(arg, "symref-target:", &arg))
+                       ref->symref = xstrdup(arg);
+
+               if (skip_prefix(arg, "peeled:", &arg)) {
+                       struct object_id peeled_oid;
+                       char *peeled_name;
+                       struct ref *peeled;
+                       if (parse_oid_hex(arg, &peeled_oid, &end) || *end) {
+                               ret = 0;
+                               goto out;
+                       }
+
+                       peeled_name = xstrfmt("%s^{}", ref->name);
+                       peeled = alloc_ref(peeled_name);
+
+                       oidcpy(&peeled->old_oid, &peeled_oid);
+                       **list = peeled;
+                       *list = &peeled->next;
+
+                       free(peeled_name);
+               }
+       }
+
+out:
+       string_list_clear(&line_sections, 0);
+       return ret;
+}
+
+struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
+                            struct ref **list, int for_push,
+                            const struct argv_array *ref_prefixes,
+                            const struct string_list *server_options)
+{
+       int i;
+       *list = NULL;
+
+       if (server_supports_v2("ls-refs", 1))
+               packet_write_fmt(fd_out, "command=ls-refs\n");
+
+       if (server_supports_v2("agent", 0))
+               packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
+
+       if (server_options && server_options->nr &&
+           server_supports_v2("server-option", 1))
+               for (i = 0; i < server_options->nr; i++)
+                       packet_write_fmt(fd_out, "server-option=%s",
+                                        server_options->items[i].string);
+
+       packet_delim(fd_out);
+       /* When pushing we don't want to request the peeled tags */
+       if (!for_push)
+               packet_write_fmt(fd_out, "peel\n");
+       packet_write_fmt(fd_out, "symrefs\n");
+       for (i = 0; ref_prefixes && i < ref_prefixes->argc; i++) {
+               packet_write_fmt(fd_out, "ref-prefix %s\n",
+                                ref_prefixes->argv[i]);
+       }
+       packet_flush(fd_out);
+
+       /* Process response from server */
+       while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+               if (!process_ref_v2(reader->line, &list))
+                       die("invalid ls-refs response: %s", reader->line);
+       }
+
+       if (reader->status != PACKET_READ_FLUSH)
+               die("expected flush after ref listing");
+
+       return list;
+}
+
 static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 {
        int len;
@@ -323,7 +493,7 @@ int parse_feature_request(const char *feature_list, const char *feature)
 
 const char *server_feature_value(const char *feature, int *len)
 {
-       return parse_feature_value(server_capabilities, feature, len);
+       return parse_feature_value(server_capabilities_v1, feature, len);
 }
 
 int server_supports(const char *feature)
@@ -872,6 +1042,7 @@ static enum ssh_variant determine_ssh_variant(const char *ssh_command,
  */
 static struct child_process *git_connect_git(int fd[2], char *hostandport,
                                             const char *path, const char *prog,
+                                            enum protocol_version version,
                                             int flags)
 {
        struct child_process *conn;
@@ -910,10 +1081,10 @@ static struct child_process *git_connect_git(int fd[2], char *hostandport,
                    target_host, 0);
 
        /* If using a new version put that stuff here after a second null byte */
-       if (get_protocol_version_config() > 0) {
+       if (version > 0) {
                strbuf_addch(&request, '\0');
                strbuf_addf(&request, "version=%d%c",
-                           get_protocol_version_config(), '\0');
+                           version, '\0');
        }
 
        packet_write(fd[1], request.buf, request.len);
@@ -929,14 +1100,14 @@ static struct child_process *git_connect_git(int fd[2], char *hostandport,
  */
 static void push_ssh_options(struct argv_array *args, struct argv_array *env,
                             enum ssh_variant variant, const char *port,
-                            int flags)
+                            enum protocol_version version, int flags)
 {
        if (variant == VARIANT_SSH &&
-           get_protocol_version_config() > 0) {
+           version > 0) {
                argv_array_push(args, "-o");
                argv_array_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
                argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
-                                get_protocol_version_config());
+                                version);
        }
 
        if (flags & CONNECT_IPV4) {
@@ -989,7 +1160,8 @@ static void push_ssh_options(struct argv_array *args, struct argv_array *env,
 
 /* Prepare a child_process for use by Git's SSH-tunneled transport. */
 static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
-                         const char *port, int flags)
+                         const char *port, enum protocol_version version,
+                         int flags)
 {
        const char *ssh;
        enum ssh_variant variant;
@@ -1023,14 +1195,14 @@ static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
                argv_array_push(&detect.args, ssh);
                argv_array_push(&detect.args, "-G");
                push_ssh_options(&detect.args, &detect.env_array,
-                                VARIANT_SSH, port, flags);
+                                VARIANT_SSH, port, version, flags);
                argv_array_push(&detect.args, ssh_host);
 
                variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH;
        }
 
        argv_array_push(&conn->args, ssh);
-       push_ssh_options(&conn->args, &conn->env_array, variant, port, flags);
+       push_ssh_options(&conn->args, &conn->env_array, variant, port, version, flags);
        argv_array_push(&conn->args, ssh_host);
 }
 
@@ -1051,6 +1223,15 @@ struct child_process *git_connect(int fd[2], const char *url,
        char *hostandport, *path;
        struct child_process *conn;
        enum protocol protocol;
+       enum protocol_version version = get_protocol_version_config();
+
+       /*
+        * NEEDSWORK: If we are trying to use protocol v2 and we are planning
+        * to perform a push, then fallback to v0 since the client doesn't know
+        * how to push yet using v2.
+        */
+       if (version == protocol_v2 && !strcmp("git-receive-pack", prog))
+               version = protocol_v0;
 
        /* Without this we cannot rely on waitpid() to tell
         * what happened to our children.
@@ -1065,7 +1246,7 @@ struct child_process *git_connect(int fd[2], const char *url,
                printf("Diag: path=%s\n", path ? path : "NULL");
                conn = NULL;
        } else if (protocol == PROTO_GIT) {
-               conn = git_connect_git(fd, hostandport, path, prog, flags);
+               conn = git_connect_git(fd, hostandport, path, prog, version, flags);
        } else {
                struct strbuf cmd = STRBUF_INIT;
                const char *const *var;
@@ -1108,12 +1289,12 @@ struct child_process *git_connect(int fd[2], const char *url,
                                strbuf_release(&cmd);
                                return NULL;
                        }
-                       fill_ssh_args(conn, ssh_host, port, flags);
+                       fill_ssh_args(conn, ssh_host, port, version, flags);
                } else {
                        transport_check_allowed("file");
-                       if (get_protocol_version_config() > 0) {
+                       if (version > 0) {
                                argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
-                                                get_protocol_version_config());
+                                                version);
                        }
                }
                argv_array_push(&conn->args, cmd.buf);