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-rw-r--r--builtin/remote-ext.c206
1 files changed, 206 insertions, 0 deletions
diff --git a/builtin/remote-ext.c b/builtin/remote-ext.c
new file mode 100644
index 0000000..282782e
--- /dev/null
+++ b/builtin/remote-ext.c
@@ -0,0 +1,206 @@
+#include "builtin.h"
+#include "transport.h"
+#include "run-command.h"
+#include "pkt-line.h"
+
+static const char usage_msg[] =
+ "git remote-ext <remote> <url>";
+
+/*
+ * URL syntax:
+ * 'command [arg1 [arg2 [...]]]' Invoke command with given arguments.
+ * Special characters:
+ * '% ': Literal space in argument.
+ * '%%': Literal percent sign.
+ * '%S': Name of service (git-upload-pack/git-upload-archive/
+ * git-receive-pack.
+ * '%s': Same as \s, but with possible git- prefix stripped.
+ * '%G': Only allowed as first 'character' of argument. Do not pass this
+ * Argument to command, instead send this as name of repository
+ * in in-line git://-style request (also activates sending this
+ * style of request).
+ * '%V': Only allowed as first 'character' of argument. Used in
+ * conjunction with '%G': Do not pass this argument to command,
+ * instead send this as vhost in git://-style request (note: does
+ * not activate sending git:// style request).
+ */
+
+static char *git_req;
+static char *git_req_vhost;
+
+static char *strip_escapes(const char *str, const char *service,
+ const char **next)
+{
+ size_t rpos = 0;
+ int escape = 0;
+ char special = 0;
+ const char *service_noprefix = service;
+ struct strbuf ret = STRBUF_INIT;
+
+ skip_prefix(service_noprefix, "git-", &service_noprefix);
+
+ /* Pass the service to command. */
+ setenv("GIT_EXT_SERVICE", service, 1);
+ setenv("GIT_EXT_SERVICE_NOPREFIX", service_noprefix, 1);
+
+ /* Scan the length of argument. */
+ while (str[rpos] && (escape || str[rpos] != ' ')) {
+ if (escape) {
+ switch (str[rpos]) {
+ case ' ':
+ case '%':
+ case 's':
+ case 'S':
+ break;
+ case 'G':
+ case 'V':
+ special = str[rpos];
+ if (rpos == 1)
+ break;
+ /* fallthrough */
+ default:
+ die("Bad remote-ext placeholder '%%%c'.",
+ str[rpos]);
+ }
+ escape = 0;
+ } else
+ escape = (str[rpos] == '%');
+ rpos++;
+ }
+ if (escape && !str[rpos])
+ die("remote-ext command has incomplete placeholder");
+ *next = str + rpos;
+ if (**next == ' ')
+ ++*next; /* Skip over space */
+
+ /*
+ * Do the actual placeholder substitution. The string will be short
+ * enough not to overflow integers.
+ */
+ rpos = special ? 2 : 0; /* Skip first 2 bytes in specials. */
+ escape = 0;
+ while (str[rpos] && (escape || str[rpos] != ' ')) {
+ if (escape) {
+ switch (str[rpos]) {
+ case ' ':
+ case '%':
+ strbuf_addch(&ret, str[rpos]);
+ break;
+ case 's':
+ strbuf_addstr(&ret, service_noprefix);
+ break;
+ case 'S':
+ strbuf_addstr(&ret, service);
+ break;
+ }
+ escape = 0;
+ } else
+ switch (str[rpos]) {
+ case '%':
+ escape = 1;
+ break;
+ default:
+ strbuf_addch(&ret, str[rpos]);
+ break;
+ }
+ rpos++;
+ }
+ switch (special) {
+ case 'G':
+ git_req = strbuf_detach(&ret, NULL);
+ return NULL;
+ case 'V':
+ git_req_vhost = strbuf_detach(&ret, NULL);
+ return NULL;
+ default:
+ return strbuf_detach(&ret, NULL);
+ }
+}
+
+static void parse_argv(struct strvec *out, const char *arg, const char *service)
+{
+ while (*arg) {
+ char *expanded = strip_escapes(arg, service, &arg);
+ if (expanded)
+ strvec_push(out, expanded);
+ free(expanded);
+ }
+}
+
+static void send_git_request(int stdin_fd, const char *serv, const char *repo,
+ const char *vhost)
+{
+ if (!vhost)
+ packet_write_fmt(stdin_fd, "%s %s%c", serv, repo, 0);
+ else
+ packet_write_fmt(stdin_fd, "%s %s%chost=%s%c", serv, repo, 0,
+ vhost, 0);
+}
+
+static int run_child(const char *arg, const char *service)
+{
+ int r;
+ struct child_process child = CHILD_PROCESS_INIT;
+
+ child.in = -1;
+ child.out = -1;
+ child.err = 0;
+ parse_argv(&child.args, arg, service);
+
+ if (start_command(&child) < 0)
+ die("Can't run specified command");
+
+ if (git_req)
+ send_git_request(child.in, service, git_req, git_req_vhost);
+
+ r = bidirectional_transfer_loop(child.out, child.in);
+ if (!r)
+ r = finish_command(&child);
+ else
+ finish_command(&child);
+ return r;
+}
+
+#define MAXCOMMAND 4096
+
+static int command_loop(const char *child)
+{
+ char buffer[MAXCOMMAND];
+
+ while (1) {
+ size_t i;
+ const char *arg;
+
+ if (!fgets(buffer, MAXCOMMAND - 1, stdin)) {
+ if (ferror(stdin))
+ die("Command input error");
+ exit(0);
+ }
+ /* Strip end of line characters. */
+ i = strlen(buffer);
+ while (i > 0 && isspace(buffer[i - 1]))
+ buffer[--i] = 0;
+
+ if (!strcmp(buffer, "capabilities")) {
+ printf("*connect\n\n");
+ fflush(stdout);
+ } else if (skip_prefix(buffer, "connect ", &arg)) {
+ printf("\n");
+ fflush(stdout);
+ return run_child(child, arg);
+ } else {
+ fprintf(stderr, "Bad command");
+ return 1;
+ }
+ }
+}
+
+int cmd_remote_ext(int argc, const char **argv, const char *prefix)
+{
+ BUG_ON_NON_EMPTY_PREFIX(prefix);
+
+ if (argc != 3)
+ usage(usage_msg);
+
+ return command_loop(argv[2]);
+}