diff options
Diffstat (limited to 'connect.c')
| -rw-r--r-- | connect.c | 572 |
1 files changed, 388 insertions, 184 deletions
@@ -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 *); @@ -108,6 +110,118 @@ static void annotate_refs_with_symref_info(struct ref *ref) } /* + * 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 */ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len, @@ -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; |