1 files changed, 112 insertions, 0 deletions
diff --git a/rsh.c b/rsh.c
new file mode 100644
index 0000000000..d66526941f
--- /dev/null
+++ b/rsh.c
@@ -0,0 +1,112 @@
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include "rsh.h"
+#include "quote.h"
+#include "cache.h"
+
+#define COMMAND_SIZE 4096
+
+/*
+ * Append a string to a string buffer, with or without shell quoting.
+ * Return true if the buffer overflowed.
+ */
+static int add_to_string(char **ptrp, int *sizep, const char *str, int quote)
+{
+	char *p = *ptrp;
+	int size = *sizep;
+	int oc;
+	int err = 0;
+
+	if ( quote ) {
+		oc = sq_quote_buf(p, size, str);
+	} else {
+		oc = strlen(str);
+		memcpy(p, str, (oc >= size) ? size-1 : oc);
+	}
+
+	if ( oc >= size ) {
+		err = 1;
+		oc = size-1;
+	}
+
+	*ptrp  += oc;
+	**ptrp  = '\0';
+	*sizep -= oc;
+	return err;
+}
+
+int setup_connection(int *fd_in, int *fd_out, const char *remote_prog, 
+		     char *url, int rmt_argc, char **rmt_argv)
+{
+	char *host;
+	char *path;
+	int sv[2];
+	char command[COMMAND_SIZE];
+	char *posn;
+	int sizen;
+	int of;
+	int i;
+
+	if (!strcmp(url, "-")) {
+		*fd_in = 0;
+		*fd_out = 1;
+		return 0;
+	}
+
+	host = strstr(url, "//");
+	if (host) {
+		host += 2;
+		path = strchr(host, '/');
+	} else {
+		host = url;
+		path = strchr(host, ':');
+		if (path)
+			*(path++) = '\0';
+	}
+	if (!path) {
+		return error("Bad URL: %s", url);
+	}
+	/* $GIT_RSH <host> "env GIT_DIR=<path> <remote_prog> <args...>" */
+	sizen = COMMAND_SIZE;
+	posn = command;
+	of = 0;
+	of |= add_to_string(&posn, &sizen, "env ", 0);
+	of |= add_to_string(&posn, &sizen, GIT_DIR_ENVIRONMENT "=", 0);
+	of |= add_to_string(&posn, &sizen, path, 1);
+	of |= add_to_string(&posn, &sizen, " ", 0);
+	of |= add_to_string(&posn, &sizen, remote_prog, 1);
+
+	for ( i = 0 ; i < rmt_argc ; i++ ) {
+		of |= add_to_string(&posn, &sizen, " ", 0);
+		of |= add_to_string(&posn, &sizen, rmt_argv[i], 1);
+	}
+
+	of |= add_to_string(&posn, &sizen, " -", 0);
+
+	if ( of )
+		return error("Command line too long");
+
+	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
+		return error("Couldn't create socket");
+
+	if (!fork()) {
+		const char *ssh, *ssh_basename;
+		ssh = getenv("GIT_SSH");
+		if (!ssh) ssh = "ssh";
+		ssh_basename = strrchr(ssh, '/');
+		if (!ssh_basename)
+			ssh_basename = ssh;
+		else
+			ssh_basename++;
+		close(sv[1]);
+		dup2(sv[0], 0);
+		dup2(sv[0], 1);
+		execlp(ssh, ssh_basename, host, command, NULL);
+	}
+	close(sv[0]);
+	*fd_in = sv[1];
+	*fd_out = sv[1];
+	return 0;
+}