Merge branch 'master' of git://github.com/git-l10n/git-po
[gitweb.git] / connect.c
index df56c0cbff4dfb1263917f6147bd7e1912418dd6..c3a014c5babf72ee4c0d135fec264afb37b040de 100644 (file)
--- a/connect.c
+++ b/connect.c
@@ -11,6 +11,8 @@
 #include "string-list.h"
 #include "sha1-array.h"
 #include "transport.h"
+#include "strbuf.h"
+#include "protocol.h"
 
 static char *server_capabilities;
 static const char *parse_feature_value(const char *, const char *, int *);
@@ -107,6 +109,118 @@ 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)
+{
+       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);
+       if (nul_location == *len)
+               return;
+       server_capabilities = xstrdup(packet_buffer + nul_location + 1);
+       *len = nul_location;
+}
+
+static int process_dummy_ref(void)
+{
+       struct object_id oid;
+       const char *name;
+
+       if (parse_oid_hex(packet_buffer, &oid, &name))
+               return 0;
+       if (*name != ' ')
+               return 0;
+       name++;
+
+       return !oidcmp(&null_oid, &oid) && !strcmp(name, "capabilities^{}");
+}
+
+static void check_no_capabilities(int len)
+{
+       if (strlen(packet_buffer) != len)
+               warning("Ignoring capabilities after first line '%s'",
+                       packet_buffer + strlen(packet_buffer));
+}
+
+static int process_ref(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))
+               return 0;
+       if (*name != ' ')
+               return 0;
+       name++;
+
+       if (extra_have && !strcmp(name, ".have")) {
+               oid_array_append(extra_have, &old_oid);
+       } else if (!strcmp(name, "capabilities^{}")) {
+               die("protocol error: unexpected capabilities^{}");
+       } else if (check_ref(name, flags)) {
+               struct ref *ref = alloc_ref(name);
+               oidcpy(&ref->old_oid, &old_oid);
+               **list = ref;
+               *list = &ref->next;
+       }
+       check_no_capabilities(len);
+       return 1;
+}
+
+static int process_shallow(int len, struct oid_array *shallow_points)
+{
+       const char *arg;
+       struct object_id old_oid;
+
+       if (!skip_prefix(packet_buffer, "shallow ", &arg))
+               return 0;
+
+       if (get_oid_hex(arg, &old_oid))
+               die("protocol error: expected shallow sha-1, got '%s'", arg);
+       if (!shallow_points)
+               die("repository on the other end cannot be shallow");
+       oid_array_append(shallow_points, &old_oid);
+       check_no_capabilities(len);
+       return 1;
+}
+
 /*
  * Read all the refs from the other end
  */
@@ -123,76 +237,41 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
         * willing to talk to us.  A hang-up before seeing any
         * response does not necessarily mean an ACL problem, though.
         */
-       int saw_response;
-       int got_dummy_ref_with_capabilities_declaration = 0;
+       int responded = 0;
+       int len;
+       int state = EXPECTING_PROTOCOL_VERSION;
 
        *list = NULL;
-       for (saw_response = 0; ; saw_response = 1) {
-               struct ref *ref;
-               struct object_id old_oid;
-               char *name;
-               int len, name_len;
-               char *buffer = packet_buffer;
-               const char *arg;
-
-               len = packet_read(in, &src_buf, &src_len,
-                                 packet_buffer, sizeof(packet_buffer),
-                                 PACKET_READ_GENTLE_ON_EOF |
-                                 PACKET_READ_CHOMP_NEWLINE);
-               if (len < 0)
-                       die_initial_contact(saw_response);
-
-               if (!len)
-                       break;
-
-               if (len > 4 && skip_prefix(buffer, "ERR ", &arg))
-                       die("remote error: %s", arg);
-
-               if (len == GIT_SHA1_HEXSZ + strlen("shallow ") &&
-                       skip_prefix(buffer, "shallow ", &arg)) {
-                       if (get_oid_hex(arg, &old_oid))
-                               die("protocol error: expected shallow sha-1, got '%s'", arg);
-                       if (!shallow_points)
-                               die("repository on the other end cannot be shallow");
-                       oid_array_append(shallow_points, &old_oid);
-                       continue;
-               }
-
-               if (len < GIT_SHA1_HEXSZ + 2 || get_oid_hex(buffer, &old_oid) ||
-                       buffer[GIT_SHA1_HEXSZ] != ' ')
-                       die("protocol error: expected sha/ref, got '%s'", buffer);
-               name = buffer + GIT_SHA1_HEXSZ + 1;
-
-               name_len = strlen(name);
-               if (len != name_len + GIT_SHA1_HEXSZ + 1) {
-                       free(server_capabilities);
-                       server_capabilities = xstrdup(name + name_len + 1);
-               }
 
-               if (extra_have && !strcmp(name, ".have")) {
-                       oid_array_append(extra_have, &old_oid);
-                       continue;
-               }
-
-               if (!strcmp(name, "capabilities^{}")) {
-                       if (saw_response)
-                               die("protocol error: unexpected capabilities^{}");
-                       if (got_dummy_ref_with_capabilities_declaration)
-                               die("protocol error: multiple capabilities^{}");
-                       got_dummy_ref_with_capabilities_declaration = 1;
-                       continue;
+       while ((len = read_remote_ref(in, &src_buf, &src_len, &responded))) {
+               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()) {
+                               state = EXPECTING_SHALLOW;
+                               break;
+                       }
+                       state = EXPECTING_REF;
+                       /* fallthrough */
+               case EXPECTING_REF:
+                       if (process_ref(len, &list, flags, extra_have))
+                               break;
+                       state = EXPECTING_SHALLOW;
+                       /* fallthrough */
+               case EXPECTING_SHALLOW:
+                       if (process_shallow(len, shallow_points))
+                               break;
+                       die("protocol error: unexpected '%s'", packet_buffer);
+               default:
+                       die("unexpected state %d", state);
                }
-
-               if (!check_ref(name, flags))
-                       continue;
-
-               if (got_dummy_ref_with_capabilities_declaration)
-                       die("protocol error: unexpected ref after capabilities^{}");
-
-               ref = alloc_ref(buffer + GIT_SHA1_HEXSZ + 1);
-               oidcpy(&ref->old_oid, &old_oid);
-               *list = ref;
-               list = &ref->next;
        }
 
        annotate_refs_with_symref_info(*orig_list);
@@ -503,12 +582,25 @@ static int git_tcp_connect_sock(char *host, int flags)
 #endif /* NO_IPV6 */
 
 
-static void git_tcp_connect(int fd[2], char *host, int flags)
+/*
+ * Dummy child_process returned by git_connect() if the transport protocol
+ * does not need fork(2).
+ */
+static struct child_process no_fork = CHILD_PROCESS_INIT;
+
+int git_connection_is_socket(struct child_process *conn)
+{
+       return conn == &no_fork;
+}
+
+static struct child_process *git_tcp_connect(int fd[2], char *host, int flags)
 {
        int sockfd = git_tcp_connect_sock(host, flags);
 
        fd[0] = sockfd;
        fd[1] = dup(sockfd);
+
+       return &no_fork;
 }
 
 
@@ -682,8 +774,6 @@ static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
        return protocol;
 }
 
-static struct child_process no_fork = CHILD_PROCESS_INIT;
-
 static const char *get_ssh_command(void)
 {
        const char *ssh;
@@ -697,37 +787,47 @@ static const char *get_ssh_command(void)
        return NULL;
 }
 
-static int override_ssh_variant(int *port_option, int *needs_batch)
+enum ssh_variant {
+       VARIANT_AUTO,
+       VARIANT_SIMPLE,
+       VARIANT_SSH,
+       VARIANT_PLINK,
+       VARIANT_PUTTY,
+       VARIANT_TORTOISEPLINK,
+};
+
+static void override_ssh_variant(enum ssh_variant *ssh_variant)
 {
-       char *variant;
+       const char *variant = getenv("GIT_SSH_VARIANT");
 
-       variant = xstrdup_or_null(getenv("GIT_SSH_VARIANT"));
-       if (!variant &&
-           git_config_get_string("ssh.variant", &variant))
-               return 0;
+       if (!variant && git_config_get_string_const("ssh.variant", &variant))
+               return;
 
-       if (!strcmp(variant, "plink") || !strcmp(variant, "putty")) {
-               *port_option = 'P';
-               *needs_batch = 0;
-       } else if (!strcmp(variant, "tortoiseplink")) {
-               *port_option = 'P';
-               *needs_batch = 1;
-       } else {
-               *port_option = 'p';
-               *needs_batch = 0;
-       }
-       free(variant);
-       return 1;
+       if (!strcmp(variant, "auto"))
+               *ssh_variant = VARIANT_AUTO;
+       else if (!strcmp(variant, "plink"))
+               *ssh_variant = VARIANT_PLINK;
+       else if (!strcmp(variant, "putty"))
+               *ssh_variant = VARIANT_PUTTY;
+       else if (!strcmp(variant, "tortoiseplink"))
+               *ssh_variant = VARIANT_TORTOISEPLINK;
+       else if (!strcmp(variant, "simple"))
+               *ssh_variant = VARIANT_SIMPLE;
+       else
+               *ssh_variant = VARIANT_SSH;
 }
 
-static void handle_ssh_variant(const char *ssh_command, int is_cmdline,
-                              int *port_option, int *needs_batch)
+static enum ssh_variant determine_ssh_variant(const char *ssh_command,
+                                             int is_cmdline)
 {
+       enum ssh_variant ssh_variant = VARIANT_AUTO;
        const char *variant;
        char *p = NULL;
 
-       if (override_ssh_variant(port_option, needs_batch))
-               return;
+       override_ssh_variant(&ssh_variant);
+
+       if (ssh_variant != VARIANT_AUTO)
+               return ssh_variant;
 
        if (!is_cmdline) {
                p = xstrdup(ssh_command);
@@ -746,27 +846,200 @@ static void handle_ssh_variant(const char *ssh_command, int is_cmdline,
                        free(ssh_argv);
                } else {
                        free(p);
-                       return;
+                       return ssh_variant;
                }
        }
 
-       if (!strcasecmp(variant, "plink") ||
-           !strcasecmp(variant, "plink.exe"))
-               *port_option = 'P';
+       if (!strcasecmp(variant, "ssh") ||
+           !strcasecmp(variant, "ssh.exe"))
+               ssh_variant = VARIANT_SSH;
+       else if (!strcasecmp(variant, "plink") ||
+                !strcasecmp(variant, "plink.exe"))
+               ssh_variant = VARIANT_PLINK;
        else if (!strcasecmp(variant, "tortoiseplink") ||
-                !strcasecmp(variant, "tortoiseplink.exe")) {
-               *port_option = 'P';
-               *needs_batch = 1;
-       }
+                !strcasecmp(variant, "tortoiseplink.exe"))
+               ssh_variant = VARIANT_TORTOISEPLINK;
+
        free(p);
+       return ssh_variant;
+}
+
+/*
+ * Open a connection using Git's native protocol.
+ *
+ * The caller is responsible for freeing hostandport, but this function may
+ * modify it (for example, to truncate it to remove the port part).
+ */
+static struct child_process *git_connect_git(int fd[2], char *hostandport,
+                                            const char *path, const char *prog,
+                                            int flags)
+{
+       struct child_process *conn;
+       struct strbuf request = STRBUF_INIT;
+       /*
+        * Set up virtual host information based on where we will
+        * connect, unless the user has overridden us in
+        * the environment.
+        */
+       char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
+       if (target_host)
+               target_host = xstrdup(target_host);
+       else
+               target_host = xstrdup(hostandport);
+
+       transport_check_allowed("git");
+
+       /*
+        * These underlying connection commands die() if they
+        * cannot connect.
+        */
+       if (git_use_proxy(hostandport))
+               conn = git_proxy_connect(fd, hostandport);
+       else
+               conn = git_tcp_connect(fd, hostandport, flags);
+       /*
+        * Separate original protocol components prog and path
+        * from extended host header with a NUL byte.
+        *
+        * Note: Do not add any other headers here!  Doing so
+        * will cause older git-daemon servers to crash.
+        */
+       strbuf_addf(&request,
+                   "%s %s%chost=%s%c",
+                   prog, path, 0,
+                   target_host, 0);
+
+       /* If using a new version put that stuff here after a second null byte */
+       if (get_protocol_version_config() > 0) {
+               strbuf_addch(&request, '\0');
+               strbuf_addf(&request, "version=%d%c",
+                           get_protocol_version_config(), '\0');
+       }
+
+       packet_write(fd[1], request.buf, request.len);
+
+       free(target_host);
+       strbuf_release(&request);
+       return conn;
+}
+
+/*
+ * Append the appropriate environment variables to `env` and options to
+ * `args` for running ssh in Git's SSH-tunneled transport.
+ */
+static void push_ssh_options(struct argv_array *args, struct argv_array *env,
+                            enum ssh_variant variant, const char *port,
+                            int flags)
+{
+       if (variant == VARIANT_SSH &&
+           get_protocol_version_config() > 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());
+       }
+
+       if (flags & CONNECT_IPV4) {
+               switch (variant) {
+               case VARIANT_AUTO:
+                       BUG("VARIANT_AUTO passed to push_ssh_options");
+               case VARIANT_SIMPLE:
+                       die("ssh variant 'simple' does not support -4");
+               case VARIANT_SSH:
+               case VARIANT_PLINK:
+               case VARIANT_PUTTY:
+               case VARIANT_TORTOISEPLINK:
+                       argv_array_push(args, "-4");
+               }
+       } else if (flags & CONNECT_IPV6) {
+               switch (variant) {
+               case VARIANT_AUTO:
+                       BUG("VARIANT_AUTO passed to push_ssh_options");
+               case VARIANT_SIMPLE:
+                       die("ssh variant 'simple' does not support -6");
+               case VARIANT_SSH:
+               case VARIANT_PLINK:
+               case VARIANT_PUTTY:
+               case VARIANT_TORTOISEPLINK:
+                       argv_array_push(args, "-6");
+               }
+       }
+
+       if (variant == VARIANT_TORTOISEPLINK)
+               argv_array_push(args, "-batch");
+
+       if (port) {
+               switch (variant) {
+               case VARIANT_AUTO:
+                       BUG("VARIANT_AUTO passed to push_ssh_options");
+               case VARIANT_SIMPLE:
+                       die("ssh variant 'simple' does not support setting port");
+               case VARIANT_SSH:
+                       argv_array_push(args, "-p");
+                       break;
+               case VARIANT_PLINK:
+               case VARIANT_PUTTY:
+               case VARIANT_TORTOISEPLINK:
+                       argv_array_push(args, "-P");
+               }
+
+               argv_array_push(args, port);
+       }
+}
+
+/* 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 *ssh;
+       enum ssh_variant variant;
+
+       if (looks_like_command_line_option(ssh_host))
+               die("strange hostname '%s' blocked", ssh_host);
+
+       ssh = get_ssh_command();
+       if (ssh) {
+               variant = determine_ssh_variant(ssh, 1);
+       } else {
+               /*
+                * GIT_SSH is the no-shell version of
+                * GIT_SSH_COMMAND (and must remain so for
+                * historical compatibility).
+                */
+               conn->use_shell = 0;
+
+               ssh = getenv("GIT_SSH");
+               if (!ssh)
+                       ssh = "ssh";
+               variant = determine_ssh_variant(ssh, 0);
+       }
+
+       if (variant == VARIANT_AUTO) {
+               struct child_process detect = CHILD_PROCESS_INIT;
+
+               detect.use_shell = conn->use_shell;
+               detect.no_stdin = detect.no_stdout = detect.no_stderr = 1;
+
+               argv_array_push(&detect.args, ssh);
+               argv_array_push(&detect.args, "-G");
+               push_ssh_options(&detect.args, &detect.env_array,
+                                VARIANT_SSH, port, 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);
+       argv_array_push(&conn->args, ssh_host);
 }
 
 /*
- * This returns a dummy child_process if the transport protocol does not
- * need fork(2), or a struct child_process object if it does.  Once done,
- * finish the connection with finish_connect() with the value returned from
- * this function (it is safe to call finish_connect() with NULL to support
- * the former case).
+ * This returns the dummy child_process `no_fork` if the transport protocol
+ * does not need fork(2), or a struct child_process object if it does.  Once
+ * done, finish the connection with finish_connect() with the value returned
+ * from this function (it is safe to call finish_connect() with NULL to
+ * support the former case).
  *
  * If it returns, the connect is successful; it just dies on errors (this
  * will hopefully be changed in a libification effort, to return NULL when
@@ -776,7 +1049,7 @@ struct child_process *git_connect(int fd[2], const char *url,
                                  const char *prog, int flags)
 {
        char *hostandport, *path;
-       struct child_process *conn = &no_fork;
+       struct child_process *conn;
        enum protocol protocol;
 
        /* Without this we cannot rely on waitpid() to tell
@@ -792,40 +1065,10 @@ 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) {
-               /*
-                * Set up virtual host information based on where we will
-                * connect, unless the user has overridden us in
-                * the environment.
-                */
-               char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
-               if (target_host)
-                       target_host = xstrdup(target_host);
-               else
-                       target_host = xstrdup(hostandport);
-
-               transport_check_allowed("git");
-
-               /* These underlying connection commands die() if they
-                * cannot connect.
-                */
-               if (git_use_proxy(hostandport))
-                       conn = git_proxy_connect(fd, hostandport);
-               else
-                       git_tcp_connect(fd, hostandport, flags);
-               /*
-                * Separate original protocol components prog and path
-                * from extended host header with a NUL byte.
-                *
-                * Note: Do not add any other headers here!  Doing so
-                * will cause older git-daemon servers to crash.
-                */
-               packet_write_fmt(fd[1],
-                            "%s %s%chost=%s%c",
-                            prog, path, 0,
-                            target_host, 0);
-               free(target_host);
+               conn = git_connect_git(fd, hostandport, path, prog, flags);
        } else {
                struct strbuf cmd = STRBUF_INIT;
+               const char *const *var;
 
                conn = xmalloc(sizeof(*conn));
                child_process_init(conn);
@@ -838,13 +1081,12 @@ struct child_process *git_connect(int fd[2], const char *url,
                sq_quote_buf(&cmd, path);
 
                /* remove repo-local variables from the environment */
-               conn->env = local_repo_env;
+               for (var = local_repo_env; *var; var++)
+                       argv_array_push(&conn->env_array, *var);
+
                conn->use_shell = 1;
                conn->in = conn->out = -1;
                if (protocol == PROTO_SSH) {
-                       const char *ssh;
-                       int needs_batch = 0;
-                       int port_option = 'p';
                        char *ssh_host = hostandport;
                        const char *port = NULL;
                        transport_check_allowed("ssh");
@@ -866,46 +1108,13 @@ struct child_process *git_connect(int fd[2], const char *url,
                                strbuf_release(&cmd);
                                return NULL;
                        }
-
-                       if (looks_like_command_line_option(ssh_host))
-                               die("strange hostname '%s' blocked", ssh_host);
-
-                       ssh = get_ssh_command();
-                       if (ssh)
-                               handle_ssh_variant(ssh, 1, &port_option,
-                                                  &needs_batch);
-                       else {
-                               /*
-                                * GIT_SSH is the no-shell version of
-                                * GIT_SSH_COMMAND (and must remain so for
-                                * historical compatibility).
-                                */
-                               conn->use_shell = 0;
-
-                               ssh = getenv("GIT_SSH");
-                               if (!ssh)
-                                       ssh = "ssh";
-                               else
-                                       handle_ssh_variant(ssh, 0,
-                                                          &port_option,
-                                                          &needs_batch);
-                       }
-
-                       argv_array_push(&conn->args, ssh);
-                       if (flags & CONNECT_IPV4)
-                               argv_array_push(&conn->args, "-4");
-                       else if (flags & CONNECT_IPV6)
-                               argv_array_push(&conn->args, "-6");
-                       if (needs_batch)
-                               argv_array_push(&conn->args, "-batch");
-                       if (port) {
-                               argv_array_pushf(&conn->args,
-                                                "-%c", port_option);
-                               argv_array_push(&conn->args, port);
-                       }
-                       argv_array_push(&conn->args, ssh_host);
+                       fill_ssh_args(conn, ssh_host, port, flags);
                } else {
                        transport_check_allowed("file");
+                       if (get_protocol_version_config() > 0) {
+                               argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
+                                                get_protocol_version_config());
+                       }
                }
                argv_array_push(&conn->args, cmd.buf);
 
@@ -921,11 +1130,6 @@ struct child_process *git_connect(int fd[2], const char *url,
        return conn;
 }
 
-int git_connection_is_socket(struct child_process *conn)
-{
-       return conn == &no_fork;
-}
-
 int finish_connect(struct child_process *conn)
 {
        int code;