sftp.c

OpenSSH 是 SSH （Secure SHell） 协议的免费开源实现。它用安全、加密的网络连接工具代替了 telnet、ftp、 rlogin、rsh 和 rcp 工具。OpenSSH 支持

/*
 * Copyright (c) 2001-2004 Damien Miller <[e-mail]>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "includes.h"

RCSID("$OpenBSD: sftp.c,v 1.62 2005/02/20 22:59:06 djm Exp $");

#ifdef USE_LIBEDIT
#include <histedit.h>
#else
typedef void EditLine;
#endif

#include "buffer.h"
#include "xmalloc.h"
#include "log.h"
#include "pathnames.h"
#include "misc.h"

#include "sftp.h"
#include "sftp-common.h"
#include "sftp-client.h"

/* File to read commands from */
FILE* infile;

/* Are we in batchfile mode? */
int batchmode = 0;

/* Size of buffer used when copying files */
size_t copy_buffer_len = 32768;

/* Number of concurrent outstanding requests */
size_t num_requests = 16;

/* PID of ssh transport process */
static pid_t sshpid = -1;

/* This is set to 0 if the progressmeter is not desired. */
int showprogress = 1;

/* SIGINT received during command processing */
volatile sig_atomic_t interrupted = 0;

/* I wish qsort() took a separate ctx for the comparison function...*/
int sort_flag;

int remote_glob(struct sftp_conn *, const char *, int,
    int (*)(const char *, int), glob_t *); /* proto for sftp-glob.c */

extern char *__progname;

/* Separators for interactive commands */
#define WHITESPACE " \t\r\n"

/* ls flags */
#define LS_LONG_VIEW	0x01	/* Full view ala ls -l */
#define LS_SHORT_VIEW	0x02	/* Single row view ala ls -1 */
#define LS_NUMERIC_VIEW	0x04	/* Long view with numeric uid/gid */
#define LS_NAME_SORT	0x08	/* Sort by name (default) */
#define LS_TIME_SORT	0x10	/* Sort by mtime */
#define LS_SIZE_SORT	0x20	/* Sort by file size */
#define LS_REVERSE_SORT	0x40	/* Reverse sort order */
#define LS_SHOW_ALL	0x80	/* Don't skip filenames starting with '.' */

#define VIEW_FLAGS	(LS_LONG_VIEW|LS_SHORT_VIEW|LS_NUMERIC_VIEW)
#define SORT_FLAGS	(LS_NAME_SORT|LS_TIME_SORT|LS_SIZE_SORT)

/* Commands for interactive mode */
#define I_CHDIR		1
#define I_CHGRP		2
#define I_CHMOD		3
#define I_CHOWN		4
#define I_GET		5
#define I_HELP		6
#define I_LCHDIR	7
#define I_LLS		8
#define I_LMKDIR	9
#define I_LPWD		10
#define I_LS		11
#define I_LUMASK	12
#define I_MKDIR		13
#define I_PUT		14
#define I_PWD		15
#define I_QUIT		16
#define I_RENAME	17
#define I_RM		18
#define I_RMDIR		19
#define I_SHELL		20
#define I_SYMLINK	21
#define I_VERSION	22
#define I_PROGRESS	23

struct CMD {
	const char *c;
	const int n;
};

static const struct CMD cmds[] = {
	{ "bye",	I_QUIT },
	{ "cd",		I_CHDIR },
	{ "chdir",	I_CHDIR },
	{ "chgrp",	I_CHGRP },
	{ "chmod",	I_CHMOD },
	{ "chown",	I_CHOWN },
	{ "dir",	I_LS },
	{ "exit",	I_QUIT },
	{ "get",	I_GET },
	{ "mget",	I_GET },
	{ "help",	I_HELP },
	{ "lcd",	I_LCHDIR },
	{ "lchdir",	I_LCHDIR },
	{ "lls",	I_LLS },
	{ "lmkdir",	I_LMKDIR },
	{ "ln",		I_SYMLINK },
	{ "lpwd",	I_LPWD },
	{ "ls",		I_LS },
	{ "lumask",	I_LUMASK },
	{ "mkdir",	I_MKDIR },
	{ "progress",	I_PROGRESS },
	{ "put",	I_PUT },
	{ "mput",	I_PUT },
	{ "pwd",	I_PWD },
	{ "quit",	I_QUIT },
	{ "rename",	I_RENAME },
	{ "rm",		I_RM },
	{ "rmdir",	I_RMDIR },
	{ "symlink",	I_SYMLINK },
	{ "version",	I_VERSION },
	{ "!",		I_SHELL },
	{ "?",		I_HELP },
	{ NULL,			-1}
};

int interactive_loop(int fd_in, int fd_out, char *file1, char *file2);

static void
killchild(int signo)
{
	if (sshpid > 1) {
		kill(sshpid, SIGTERM);
		waitpid(sshpid, NULL, 0);
	}

	_exit(1);
}

static void
cmd_interrupt(int signo)
{
	const char msg[] = "\rInterrupt  \n";
	int olderrno = errno;

	write(STDERR_FILENO, msg, sizeof(msg) - 1);
	interrupted = 1;
	errno = olderrno;
}

static void
help(void)
{
	printf("Available commands:\n");
	printf("cd path                       Change remote directory to 'path'\n");
	printf("lcd path                      Change local directory to 'path'\n");
	printf("chgrp grp path                Change group of file 'path' to 'grp'\n");
	printf("chmod mode path               Change permissions of file 'path' to 'mode'\n");
	printf("chown own path                Change owner of file 'path' to 'own'\n");
	printf("help                          Display this help text\n");
	printf("get remote-path [local-path]  Download file\n");
	printf("lls [ls-options [path]]       Display local directory listing\n");
	printf("ln oldpath newpath            Symlink remote file\n");
	printf("lmkdir path                   Create local directory\n");
	printf("lpwd                          Print local working directory\n");
	printf("ls [path]                     Display remote directory listing\n");
	printf("lumask umask                  Set local umask to 'umask'\n");
	printf("mkdir path                    Create remote directory\n");
	printf("progress                      Toggle display of progress meter\n");
	printf("put local-path [remote-path]  Upload file\n");
	printf("pwd                           Display remote working directory\n");
	printf("exit                          Quit sftp\n");
	printf("quit                          Quit sftp\n");
	printf("rename oldpath newpath        Rename remote file\n");
	printf("rmdir path                    Remove remote directory\n");
	printf("rm path                       Delete remote file\n");
	printf("symlink oldpath newpath       Symlink remote file\n");
	printf("version                       Show SFTP version\n");
	printf("!command                      Execute 'command' in local shell\n");
	printf("!                             Escape to local shell\n");
	printf("?                             Synonym for help\n");
}

static void
local_do_shell(const char *args)
{
	int status;
	char *shell;
	pid_t pid;

	if (!*args)
		args = NULL;

	if ((shell = getenv("SHELL")) == NULL)
		shell = _PATH_BSHELL;

	if ((pid = fork()) == -1)
		fatal("Couldn't fork: %s", strerror(errno));

	if (pid == 0) {
		/* XXX: child has pipe fds to ssh subproc open - issue? */
		if (args) {
			debug3("Executing %s -c \"%s\"", shell, args);
			execl(shell, shell, "-c", args, (char *)NULL);
		} else {
			debug3("Executing %s", shell);
			execl(shell, shell, (char *)NULL);
		}
		fprintf(stderr, "Couldn't execute \"%s\": %s\n", shell,
		    strerror(errno));
		_exit(1);
	}
	while (waitpid(pid, &status, 0) == -1)
		if (errno != EINTR)
			fatal("Couldn't wait for child: %s", strerror(errno));
	if (!WIFEXITED(status))
		error("Shell exited abormally");
	else if (WEXITSTATUS(status))
		error("Shell exited with status %d", WEXITSTATUS(status));
}

static void
local_do_ls(const char *args)
{
	if (!args || !*args)
		local_do_shell(_PATH_LS);
	else {
		int len = strlen(_PATH_LS " ") + strlen(args) + 1;
		char *buf = xmalloc(len);

		/* XXX: quoting - rip quoting code from ftp? */
		snprintf(buf, len, _PATH_LS " %s", args);
		local_do_shell(buf);
		xfree(buf);
	}
}

/* Strip one path (usually the pwd) from the start of another */
static char *
path_strip(char *path, char *strip)
{
	size_t len;

	if (strip == NULL)
		return (xstrdup(path));

	len = strlen(strip);
	if (strncmp(path, strip, len) == 0) {
		if (strip[len - 1] != '/' && path[len] == '/')
			len++;
		return (xstrdup(path + len));
	}

	return (xstrdup(path));
}

static char *
path_append(char *p1, char *p2)
{
	char *ret;
	int len = strlen(p1) + strlen(p2) + 2;

	ret = xmalloc(len);
	strlcpy(ret, p1, len);
	if (p1[strlen(p1) - 1] != '/')
		strlcat(ret, "/", len);
	strlcat(ret, p2, len);

	return(ret);
}

static char *
make_absolute(char *p, char *pwd)
{
	char *abs_str;

	/* Derelativise */
	if (p && p[0] != '/') {
		abs_str = path_append(pwd, p);
		xfree(p);
		return(abs_str);
	} else
		return(p);
}

static int
infer_path(const char *p, char **ifp)
{
	char *cp;

	cp = strrchr(p, '/');
	if (cp == NULL) {
		*ifp = xstrdup(p);
		return(0);
	}

	if (!cp[1]) {
		error("Invalid path");
		return(-1);
	}

	*ifp = xstrdup(cp + 1);
	return(0);
}

static int
parse_getput_flags(const char **cpp, int *pflag)
{
	const char *cp = *cpp;

	/* Check for flags */
	if (cp[0] == '-' && cp[1] && strchr(WHITESPACE, cp[2])) {
		switch (cp[1]) {
		case 'p':
		case 'P':
			*pflag = 1;
			break;
		default:
			error("Invalid flag -%c", cp[1]);
			return(-1);
		}
		cp += 2;
		*cpp = cp + strspn(cp, WHITESPACE);
	}

	return(0);
}

static int
parse_ls_flags(const char **cpp, int *lflag)
{
	const char *cp = *cpp;

	/* Defaults */
	*lflag = LS_NAME_SORT;

	/* Check for flags */
	if (cp++[0] == '-') {
		for(; strchr(WHITESPACE, *cp) == NULL; cp++) {
			switch (*cp) {
			case 'l':
				*lflag &= ~VIEW_FLAGS;
				*lflag |= LS_LONG_VIEW;
				break;
			case '1':
				*lflag &= ~VIEW_FLAGS;
				*lflag |= LS_SHORT_VIEW;
				break;
			case 'n':
				*lflag &= ~VIEW_FLAGS;
				*lflag |= LS_NUMERIC_VIEW|LS_LONG_VIEW;
				break;
			case 'S':
				*lflag &= ~SORT_FLAGS;
				*lflag |= LS_SIZE_SORT;
				break;
			case 't':
				*lflag &= ~SORT_FLAGS;
				*lflag |= LS_TIME_SORT;
				break;
			case 'r':
				*lflag |= LS_REVERSE_SORT;
				break;
			case 'f':
				*lflag &= ~SORT_FLAGS;
				break;
			case 'a':
				*lflag |= LS_SHOW_ALL;
				break;
			default:
				error("Invalid flag -%c", *cp);
				return(-1);
			}
		}
		*cpp = cp + strspn(cp, WHITESPACE);
	}

	return(0);
}

static int
get_pathname(const char **cpp, char **path)
{
	const char *cp = *cpp, *end;
	char quot;
	int i, j;

	cp += strspn(cp, WHITESPACE);
	if (!*cp) {
		*cpp = cp;
		*path = NULL;
		return (0);
	}

	*path = xmalloc(strlen(cp) + 1);

	/* Check for quoted filenames */
	if (*cp == '\"' || *cp == '\'') {
		quot = *cp++;

		/* Search for terminating quote, unescape some chars */
		for (i = j = 0; i <= strlen(cp); i++) {
			if (cp[i] == quot) {	/* Found quote */
				i++;
				(*path)[j] = '\0';
				break;
			}
			if (cp[i] == '\0') {	/* End of string */
				error("Unterminated quote");
				goto fail;
			}
			if (cp[i] == '\\') {	/* Escaped characters */
				i++;
				if (cp[i] != '\'' && cp[i] != '\"' &&
				    cp[i] != '\\') {
					error("Bad escaped character '\\%c'",
					    cp[i]);
					goto fail;
				}
			}
			(*path)[j++] = cp[i];
		}

		if (j == 0) {
			error("Empty quotes");
			goto fail;
		}
		*cpp = cp + i + strspn(cp + i, WHITESPACE);
	} else {
		/* Read to end of filename */
		end = strpbrk(cp, WHITESPACE);
		if (end == NULL)
			end = strchr(cp, '\0');
		*cpp = end + strspn(end, WHITESPACE);

		memcpy(*path, cp, end - cp);
		(*path)[end - cp] = '\0';
	}
	return (0);

 fail:
	xfree(*path);
	*path = NULL;
	return (-1);
}

static int
is_dir(char *path)
{
	struct stat sb;

	/* XXX: report errors? */
	if (stat(path, &sb) == -1)
		return(0);

	return(sb.st_mode & S_IFDIR);
}

static int
is_reg(char *path)
{
	struct stat sb;

	if (stat(path, &sb) == -1)
		fatal("stat %s: %s", path, strerror(errno));

	return(S_ISREG(sb.st_mode));
}

static int
remote_is_dir(struct sftp_conn *conn, char *path)
{
	Attrib *a;

	/* XXX: report errors? */
	if ((a = do_stat(conn, path, 1)) == NULL)
		return(0);
	if (!(a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS))
		return(0);
	return(a->perm & S_IFDIR);
}

static int
process_get(struct sftp_conn *conn, char *src, char *dst, char *pwd, int pflag)
{
	char *abs_src = NULL;
	char *abs_dst = NULL;
	char *tmp;
	glob_t g;
	int err = 0;
	int i;

	abs_src = xstrdup(src);
	abs_src = make_absolute(abs_src, pwd);

	memset(&g, 0, sizeof(g));
	debug3("Looking up %s", abs_src);
	if (remote_glob(conn, abs_src, 0, NULL, &g)) {
		error("File \"%s\" not found.", abs_src);
		err = -1;
		goto out;
	}

	/* If multiple matches, dst must be a directory or unspecified */
	if (g.gl_matchc > 1 && dst && !is_dir(dst)) {
		error("Multiple files match, but \"%s\" is not a directory",