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-rw-r--r--sftp-server.c1710
1 files changed, 1710 insertions, 0 deletions
diff --git a/sftp-server.c b/sftp-server.c
new file mode 100644
index 0000000..ab1b063
--- /dev/null
+++ b/sftp-server.c
@@ -0,0 +1,1710 @@
+/* $OpenBSD: sftp-server.c,v 1.112 2018/06/01 03:33:53 djm Exp $ */
+/*
+ * Copyright (c) 2000-2004 Markus Friedl. All rights reserved.
+ *
+ * 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"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#ifdef HAVE_SYS_MOUNT_H
+#include <sys/mount.h>
+#endif
+#ifdef HAVE_SYS_STATVFS_H
+#include <sys/statvfs.h>
+#endif
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <stdarg.h>
+
+#include "xmalloc.h"
+#include "sshbuf.h"
+#include "ssherr.h"
+#include "log.h"
+#include "misc.h"
+#include "match.h"
+#include "uidswap.h"
+
+#include "sftp.h"
+#include "sftp-common.h"
+
+/* Our verbosity */
+static LogLevel log_level = SYSLOG_LEVEL_ERROR;
+
+/* Our client */
+static struct passwd *pw = NULL;
+static char *client_addr = NULL;
+
+/* input and output queue */
+struct sshbuf *iqueue;
+struct sshbuf *oqueue;
+
+/* Version of client */
+static u_int version;
+
+/* SSH2_FXP_INIT received */
+static int init_done;
+
+/* Disable writes */
+static int readonly;
+
+/* Requests that are allowed/denied */
+static char *request_whitelist, *request_blacklist;
+
+/* portable attributes, etc. */
+typedef struct Stat Stat;
+
+struct Stat {
+ char *name;
+ char *long_name;
+ Attrib attrib;
+};
+
+/* Packet handlers */
+static void process_open(u_int32_t id);
+static void process_close(u_int32_t id);
+static void process_read(u_int32_t id);
+static void process_write(u_int32_t id);
+static void process_stat(u_int32_t id);
+static void process_lstat(u_int32_t id);
+static void process_fstat(u_int32_t id);
+static void process_setstat(u_int32_t id);
+static void process_fsetstat(u_int32_t id);
+static void process_opendir(u_int32_t id);
+static void process_readdir(u_int32_t id);
+static void process_remove(u_int32_t id);
+static void process_mkdir(u_int32_t id);
+static void process_rmdir(u_int32_t id);
+static void process_realpath(u_int32_t id);
+static void process_rename(u_int32_t id);
+static void process_readlink(u_int32_t id);
+static void process_symlink(u_int32_t id);
+static void process_extended_posix_rename(u_int32_t id);
+static void process_extended_statvfs(u_int32_t id);
+static void process_extended_fstatvfs(u_int32_t id);
+static void process_extended_hardlink(u_int32_t id);
+static void process_extended_fsync(u_int32_t id);
+static void process_extended(u_int32_t id);
+
+struct sftp_handler {
+ const char *name; /* user-visible name for fine-grained perms */
+ const char *ext_name; /* extended request name */
+ u_int type; /* packet type, for non extended packets */
+ void (*handler)(u_int32_t);
+ int does_write; /* if nonzero, banned for readonly mode */
+};
+
+struct sftp_handler handlers[] = {
+ /* NB. SSH2_FXP_OPEN does the readonly check in the handler itself */
+ { "open", NULL, SSH2_FXP_OPEN, process_open, 0 },
+ { "close", NULL, SSH2_FXP_CLOSE, process_close, 0 },
+ { "read", NULL, SSH2_FXP_READ, process_read, 0 },
+ { "write", NULL, SSH2_FXP_WRITE, process_write, 1 },
+ { "lstat", NULL, SSH2_FXP_LSTAT, process_lstat, 0 },
+ { "fstat", NULL, SSH2_FXP_FSTAT, process_fstat, 0 },
+ { "setstat", NULL, SSH2_FXP_SETSTAT, process_setstat, 1 },
+ { "fsetstat", NULL, SSH2_FXP_FSETSTAT, process_fsetstat, 1 },
+ { "opendir", NULL, SSH2_FXP_OPENDIR, process_opendir, 0 },
+ { "readdir", NULL, SSH2_FXP_READDIR, process_readdir, 0 },
+ { "remove", NULL, SSH2_FXP_REMOVE, process_remove, 1 },
+ { "mkdir", NULL, SSH2_FXP_MKDIR, process_mkdir, 1 },
+ { "rmdir", NULL, SSH2_FXP_RMDIR, process_rmdir, 1 },
+ { "realpath", NULL, SSH2_FXP_REALPATH, process_realpath, 0 },
+ { "stat", NULL, SSH2_FXP_STAT, process_stat, 0 },
+ { "rename", NULL, SSH2_FXP_RENAME, process_rename, 1 },
+ { "readlink", NULL, SSH2_FXP_READLINK, process_readlink, 0 },
+ { "symlink", NULL, SSH2_FXP_SYMLINK, process_symlink, 1 },
+ { NULL, NULL, 0, NULL, 0 }
+};
+
+/* SSH2_FXP_EXTENDED submessages */
+struct sftp_handler extended_handlers[] = {
+ { "posix-rename", "posix-rename@openssh.com", 0,
+ process_extended_posix_rename, 1 },
+ { "statvfs", "statvfs@openssh.com", 0, process_extended_statvfs, 0 },
+ { "fstatvfs", "fstatvfs@openssh.com", 0, process_extended_fstatvfs, 0 },
+ { "hardlink", "hardlink@openssh.com", 0, process_extended_hardlink, 1 },
+ { "fsync", "fsync@openssh.com", 0, process_extended_fsync, 1 },
+ { NULL, NULL, 0, NULL, 0 }
+};
+
+static int
+request_permitted(struct sftp_handler *h)
+{
+ char *result;
+
+ if (readonly && h->does_write) {
+ verbose("Refusing %s request in read-only mode", h->name);
+ return 0;
+ }
+ if (request_blacklist != NULL &&
+ ((result = match_list(h->name, request_blacklist, NULL))) != NULL) {
+ free(result);
+ verbose("Refusing blacklisted %s request", h->name);
+ return 0;
+ }
+ if (request_whitelist != NULL &&
+ ((result = match_list(h->name, request_whitelist, NULL))) != NULL) {
+ free(result);
+ debug2("Permitting whitelisted %s request", h->name);
+ return 1;
+ }
+ if (request_whitelist != NULL) {
+ verbose("Refusing non-whitelisted %s request", h->name);
+ return 0;
+ }
+ return 1;
+}
+
+static int
+errno_to_portable(int unixerrno)
+{
+ int ret = 0;
+
+ switch (unixerrno) {
+ case 0:
+ ret = SSH2_FX_OK;
+ break;
+ case ENOENT:
+ case ENOTDIR:
+ case EBADF:
+ case ELOOP:
+ ret = SSH2_FX_NO_SUCH_FILE;
+ break;
+ case EPERM:
+ case EACCES:
+ case EFAULT:
+ ret = SSH2_FX_PERMISSION_DENIED;
+ break;
+ case ENAMETOOLONG:
+ case EINVAL:
+ ret = SSH2_FX_BAD_MESSAGE;
+ break;
+ case ENOSYS:
+ ret = SSH2_FX_OP_UNSUPPORTED;
+ break;
+ default:
+ ret = SSH2_FX_FAILURE;
+ break;
+ }
+ return ret;
+}
+
+static int
+flags_from_portable(int pflags)
+{
+ int flags = 0;
+
+ if ((pflags & SSH2_FXF_READ) &&
+ (pflags & SSH2_FXF_WRITE)) {
+ flags = O_RDWR;
+ } else if (pflags & SSH2_FXF_READ) {
+ flags = O_RDONLY;
+ } else if (pflags & SSH2_FXF_WRITE) {
+ flags = O_WRONLY;
+ }
+ if (pflags & SSH2_FXF_APPEND)
+ flags |= O_APPEND;
+ if (pflags & SSH2_FXF_CREAT)
+ flags |= O_CREAT;
+ if (pflags & SSH2_FXF_TRUNC)
+ flags |= O_TRUNC;
+ if (pflags & SSH2_FXF_EXCL)
+ flags |= O_EXCL;
+ return flags;
+}
+
+static const char *
+string_from_portable(int pflags)
+{
+ static char ret[128];
+
+ *ret = '\0';
+
+#define PAPPEND(str) { \
+ if (*ret != '\0') \
+ strlcat(ret, ",", sizeof(ret)); \
+ strlcat(ret, str, sizeof(ret)); \
+ }
+
+ if (pflags & SSH2_FXF_READ)
+ PAPPEND("READ")
+ if (pflags & SSH2_FXF_WRITE)
+ PAPPEND("WRITE")
+ if (pflags & SSH2_FXF_APPEND)
+ PAPPEND("APPEND")
+ if (pflags & SSH2_FXF_CREAT)
+ PAPPEND("CREATE")
+ if (pflags & SSH2_FXF_TRUNC)
+ PAPPEND("TRUNCATE")
+ if (pflags & SSH2_FXF_EXCL)
+ PAPPEND("EXCL")
+
+ return ret;
+}
+
+/* handle handles */
+
+typedef struct Handle Handle;
+struct Handle {
+ int use;
+ DIR *dirp;
+ int fd;
+ int flags;
+ char *name;
+ u_int64_t bytes_read, bytes_write;
+ int next_unused;
+};
+
+enum {
+ HANDLE_UNUSED,
+ HANDLE_DIR,
+ HANDLE_FILE
+};
+
+Handle *handles = NULL;
+u_int num_handles = 0;
+int first_unused_handle = -1;
+
+static void handle_unused(int i)
+{
+ handles[i].use = HANDLE_UNUSED;
+ handles[i].next_unused = first_unused_handle;
+ first_unused_handle = i;
+}
+
+static int
+handle_new(int use, const char *name, int fd, int flags, DIR *dirp)
+{
+ int i;
+
+ if (first_unused_handle == -1) {
+ if (num_handles + 1 <= num_handles)
+ return -1;
+ num_handles++;
+ handles = xreallocarray(handles, num_handles, sizeof(Handle));
+ handle_unused(num_handles - 1);
+ }
+
+ i = first_unused_handle;
+ first_unused_handle = handles[i].next_unused;
+
+ handles[i].use = use;
+ handles[i].dirp = dirp;
+ handles[i].fd = fd;
+ handles[i].flags = flags;
+ handles[i].name = xstrdup(name);
+ handles[i].bytes_read = handles[i].bytes_write = 0;
+
+ return i;
+}
+
+static int
+handle_is_ok(int i, int type)
+{
+ return i >= 0 && (u_int)i < num_handles && handles[i].use == type;
+}
+
+static int
+handle_to_string(int handle, u_char **stringp, int *hlenp)
+{
+ if (stringp == NULL || hlenp == NULL)
+ return -1;
+ *stringp = xmalloc(sizeof(int32_t));
+ put_u32(*stringp, handle);
+ *hlenp = sizeof(int32_t);
+ return 0;
+}
+
+static int
+handle_from_string(const u_char *handle, u_int hlen)
+{
+ int val;
+
+ if (hlen != sizeof(int32_t))
+ return -1;
+ val = get_u32(handle);
+ if (handle_is_ok(val, HANDLE_FILE) ||
+ handle_is_ok(val, HANDLE_DIR))
+ return val;
+ return -1;
+}
+
+static char *
+handle_to_name(int handle)
+{
+ if (handle_is_ok(handle, HANDLE_DIR)||
+ handle_is_ok(handle, HANDLE_FILE))
+ return handles[handle].name;
+ return NULL;
+}
+
+static DIR *
+handle_to_dir(int handle)
+{
+ if (handle_is_ok(handle, HANDLE_DIR))
+ return handles[handle].dirp;
+ return NULL;
+}
+
+static int
+handle_to_fd(int handle)
+{
+ if (handle_is_ok(handle, HANDLE_FILE))
+ return handles[handle].fd;
+ return -1;
+}
+
+static int
+handle_to_flags(int handle)
+{
+ if (handle_is_ok(handle, HANDLE_FILE))
+ return handles[handle].flags;
+ return 0;
+}
+
+static void
+handle_update_read(int handle, ssize_t bytes)
+{
+ if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
+ handles[handle].bytes_read += bytes;
+}
+
+static void
+handle_update_write(int handle, ssize_t bytes)
+{
+ if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
+ handles[handle].bytes_write += bytes;
+}
+
+static u_int64_t
+handle_bytes_read(int handle)
+{
+ if (handle_is_ok(handle, HANDLE_FILE))
+ return (handles[handle].bytes_read);
+ return 0;
+}
+
+static u_int64_t
+handle_bytes_write(int handle)
+{
+ if (handle_is_ok(handle, HANDLE_FILE))
+ return (handles[handle].bytes_write);
+ return 0;
+}
+
+static int
+handle_close(int handle)
+{
+ int ret = -1;
+
+ if (handle_is_ok(handle, HANDLE_FILE)) {
+ ret = close(handles[handle].fd);
+ free(handles[handle].name);
+ handle_unused(handle);
+ } else if (handle_is_ok(handle, HANDLE_DIR)) {
+ ret = closedir(handles[handle].dirp);
+ free(handles[handle].name);
+ handle_unused(handle);
+ } else {
+ errno = ENOENT;
+ }
+ return ret;
+}
+
+static void
+handle_log_close(int handle, char *emsg)
+{
+ if (handle_is_ok(handle, HANDLE_FILE)) {
+ logit("%s%sclose \"%s\" bytes read %llu written %llu",
+ emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
+ handle_to_name(handle),
+ (unsigned long long)handle_bytes_read(handle),
+ (unsigned long long)handle_bytes_write(handle));
+ } else {
+ logit("%s%sclosedir \"%s\"",
+ emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
+ handle_to_name(handle));
+ }
+}
+
+static void
+handle_log_exit(void)
+{
+ u_int i;
+
+ for (i = 0; i < num_handles; i++)
+ if (handles[i].use != HANDLE_UNUSED)
+ handle_log_close(i, "forced");
+}
+
+static int
+get_handle(struct sshbuf *queue, int *hp)
+{
+ u_char *handle;
+ int r;
+ size_t hlen;
+
+ *hp = -1;
+ if ((r = sshbuf_get_string(queue, &handle, &hlen)) != 0)
+ return r;
+ if (hlen < 256)
+ *hp = handle_from_string(handle, hlen);
+ free(handle);
+ return 0;
+}
+
+/* send replies */
+
+static void
+send_msg(struct sshbuf *m)
+{
+ int r;
+
+ if ((r = sshbuf_put_stringb(oqueue, m)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ sshbuf_reset(m);
+}
+
+static const char *
+status_to_message(u_int32_t status)
+{
+ const char *status_messages[] = {
+ "Success", /* SSH_FX_OK */
+ "End of file", /* SSH_FX_EOF */
+ "No such file", /* SSH_FX_NO_SUCH_FILE */
+ "Permission denied", /* SSH_FX_PERMISSION_DENIED */
+ "Failure", /* SSH_FX_FAILURE */
+ "Bad message", /* SSH_FX_BAD_MESSAGE */
+ "No connection", /* SSH_FX_NO_CONNECTION */
+ "Connection lost", /* SSH_FX_CONNECTION_LOST */
+ "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */
+ "Unknown error" /* Others */
+ };
+ return (status_messages[MINIMUM(status,SSH2_FX_MAX)]);
+}
+
+static void
+send_status(u_int32_t id, u_int32_t status)
+{
+ struct sshbuf *msg;
+ int r;
+
+ debug3("request %u: sent status %u", id, status);
+ if (log_level > SYSLOG_LEVEL_VERBOSE ||
+ (status != SSH2_FX_OK && status != SSH2_FX_EOF))
+ logit("sent status %s", status_to_message(status));
+ if ((msg = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+ if ((r = sshbuf_put_u8(msg, SSH2_FXP_STATUS)) != 0 ||
+ (r = sshbuf_put_u32(msg, id)) != 0 ||
+ (r = sshbuf_put_u32(msg, status)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ if (version >= 3) {
+ if ((r = sshbuf_put_cstring(msg,
+ status_to_message(status))) != 0 ||
+ (r = sshbuf_put_cstring(msg, "")) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ }
+ send_msg(msg);
+ sshbuf_free(msg);
+}
+static void
+send_data_or_handle(char type, u_int32_t id, const u_char *data, int dlen)
+{
+ struct sshbuf *msg;
+ int r;
+
+ if ((msg = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+ if ((r = sshbuf_put_u8(msg, type)) != 0 ||
+ (r = sshbuf_put_u32(msg, id)) != 0 ||
+ (r = sshbuf_put_string(msg, data, dlen)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ send_msg(msg);
+ sshbuf_free(msg);
+}
+
+static void
+send_data(u_int32_t id, const u_char *data, int dlen)
+{
+ debug("request %u: sent data len %d", id, dlen);
+ send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
+}
+
+static void
+send_handle(u_int32_t id, int handle)
+{
+ u_char *string;
+ int hlen;
+
+ handle_to_string(handle, &string, &hlen);
+ debug("request %u: sent handle handle %d", id, handle);
+ send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
+ free(string);
+}
+
+static void
+send_names(u_int32_t id, int count, const Stat *stats)
+{
+ struct sshbuf *msg;
+ int i, r;
+
+ if ((msg = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+ if ((r = sshbuf_put_u8(msg, SSH2_FXP_NAME)) != 0 ||
+ (r = sshbuf_put_u32(msg, id)) != 0 ||
+ (r = sshbuf_put_u32(msg, count)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ debug("request %u: sent names count %d", id, count);
+ for (i = 0; i < count; i++) {
+ if ((r = sshbuf_put_cstring(msg, stats[i].name)) != 0 ||
+ (r = sshbuf_put_cstring(msg, stats[i].long_name)) != 0 ||
+ (r = encode_attrib(msg, &stats[i].attrib)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ }
+ send_msg(msg);
+ sshbuf_free(msg);
+}
+
+static void
+send_attrib(u_int32_t id, const Attrib *a)
+{
+ struct sshbuf *msg;
+ int r;
+
+ debug("request %u: sent attrib have 0x%x", id, a->flags);
+ if ((msg = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+ if ((r = sshbuf_put_u8(msg, SSH2_FXP_ATTRS)) != 0 ||
+ (r = sshbuf_put_u32(msg, id)) != 0 ||
+ (r = encode_attrib(msg, a)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ send_msg(msg);
+ sshbuf_free(msg);
+}
+
+static void
+send_statvfs(u_int32_t id, struct statvfs *st)
+{
+ struct sshbuf *msg;
+ u_int64_t flag;
+ int r;
+
+ flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0;
+ flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0;
+
+ if ((msg = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+ if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 ||
+ (r = sshbuf_put_u32(msg, id)) != 0 ||
+ (r = sshbuf_put_u64(msg, st->f_bsize)) != 0 ||
+ (r = sshbuf_put_u64(msg, st->f_frsize)) != 0 ||
+ (r = sshbuf_put_u64(msg, st->f_blocks)) != 0 ||
+ (r = sshbuf_put_u64(msg, st->f_bfree)) != 0 ||
+ (r = sshbuf_put_u64(msg, st->f_bavail)) != 0 ||
+ (r = sshbuf_put_u64(msg, st->f_files)) != 0 ||
+ (r = sshbuf_put_u64(msg, st->f_ffree)) != 0 ||
+ (r = sshbuf_put_u64(msg, st->f_favail)) != 0 ||
+ (r = sshbuf_put_u64(msg, FSID_TO_ULONG(st->f_fsid))) != 0 ||
+ (r = sshbuf_put_u64(msg, flag)) != 0 ||
+ (r = sshbuf_put_u64(msg, st->f_namemax)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ send_msg(msg);
+ sshbuf_free(msg);
+}
+
+/* parse incoming */
+
+static void
+process_init(void)
+{
+ struct sshbuf *msg;
+ int r;
+
+ if ((r = sshbuf_get_u32(iqueue, &version)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ verbose("received client version %u", version);
+ if ((msg = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+ if ((r = sshbuf_put_u8(msg, SSH2_FXP_VERSION)) != 0 ||
+ (r = sshbuf_put_u32(msg, SSH2_FILEXFER_VERSION)) != 0 ||
+ /* POSIX rename extension */
+ (r = sshbuf_put_cstring(msg, "posix-rename@openssh.com")) != 0 ||
+ (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */
+ /* statvfs extension */
+ (r = sshbuf_put_cstring(msg, "statvfs@openssh.com")) != 0 ||
+ (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */
+ /* fstatvfs extension */
+ (r = sshbuf_put_cstring(msg, "fstatvfs@openssh.com")) != 0 ||
+ (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */
+ /* hardlink extension */
+ (r = sshbuf_put_cstring(msg, "hardlink@openssh.com")) != 0 ||
+ (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */
+ /* fsync extension */
+ (r = sshbuf_put_cstring(msg, "fsync@openssh.com")) != 0 ||
+ (r = sshbuf_put_cstring(msg, "1")) != 0) /* version */
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ send_msg(msg);
+ sshbuf_free(msg);
+}
+
+static void
+process_open(u_int32_t id)
+{
+ u_int32_t pflags;
+ Attrib a;
+ char *name;
+ int r, handle, fd, flags, mode, status = SSH2_FX_FAILURE;
+
+ if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
+ (r = sshbuf_get_u32(iqueue, &pflags)) != 0 || /* portable flags */
+ (r = decode_attrib(iqueue, &a)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: open flags %d", id, pflags);
+ flags = flags_from_portable(pflags);
+ mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a.perm : 0666;
+ logit("open \"%s\" flags %s mode 0%o",
+ name, string_from_portable(pflags), mode);
+ if (readonly &&
+ ((flags & O_ACCMODE) != O_RDONLY ||
+ (flags & (O_CREAT|O_TRUNC)) != 0)) {
+ verbose("Refusing open request in read-only mode");
+ status = SSH2_FX_PERMISSION_DENIED;
+ } else {
+ fd = open(name, flags, mode);
+ if (fd < 0) {
+ status = errno_to_portable(errno);
+ } else {
+ handle = handle_new(HANDLE_FILE, name, fd, flags, NULL);
+ if (handle < 0) {
+ close(fd);
+ } else {
+ send_handle(id, handle);
+ status = SSH2_FX_OK;
+ }
+ }
+ }
+ if (status != SSH2_FX_OK)
+ send_status(id, status);
+ free(name);
+}
+
+static void
+process_close(u_int32_t id)
+{
+ int r, handle, ret, status = SSH2_FX_FAILURE;
+
+ if ((r = get_handle(iqueue, &handle)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: close handle %u", id, handle);
+ handle_log_close(handle, NULL);
+ ret = handle_close(handle);
+ status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+ send_status(id, status);
+}
+
+static void
+process_read(u_int32_t id)
+{
+ u_char buf[64*1024];
+ u_int32_t len;
+ int r, handle, fd, ret, status = SSH2_FX_FAILURE;
+ u_int64_t off;
+
+ if ((r = get_handle(iqueue, &handle)) != 0 ||
+ (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
+ (r = sshbuf_get_u32(iqueue, &len)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug("request %u: read \"%s\" (handle %d) off %llu len %d",
+ id, handle_to_name(handle), handle, (unsigned long long)off, len);
+ if (len > sizeof buf) {
+ len = sizeof buf;
+ debug2("read change len %d", len);
+ }
+ fd = handle_to_fd(handle);
+ if (fd >= 0) {
+ if (lseek(fd, off, SEEK_SET) < 0) {
+ error("process_read: seek failed");
+ status = errno_to_portable(errno);
+ } else {
+ ret = read(fd, buf, len);
+ if (ret < 0) {
+ status = errno_to_portable(errno);
+ } else if (ret == 0) {
+ status = SSH2_FX_EOF;
+ } else {
+ send_data(id, buf, ret);
+ status = SSH2_FX_OK;
+ handle_update_read(handle, ret);
+ }
+ }
+ }
+ if (status != SSH2_FX_OK)
+ send_status(id, status);
+}
+
+static void
+process_write(u_int32_t id)
+{
+ u_int64_t off;
+ size_t len;
+ int r, handle, fd, ret, status;
+ u_char *data;
+
+ if ((r = get_handle(iqueue, &handle)) != 0 ||
+ (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
+ (r = sshbuf_get_string(iqueue, &data, &len)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug("request %u: write \"%s\" (handle %d) off %llu len %zu",
+ id, handle_to_name(handle), handle, (unsigned long long)off, len);
+ fd = handle_to_fd(handle);
+
+ if (fd < 0)
+ status = SSH2_FX_FAILURE;
+ else {
+ if (!(handle_to_flags(handle) & O_APPEND) &&
+ lseek(fd, off, SEEK_SET) < 0) {
+ status = errno_to_portable(errno);
+ error("process_write: seek failed");
+ } else {
+/* XXX ATOMICIO ? */
+ ret = write(fd, data, len);
+ if (ret < 0) {
+ error("process_write: write failed");
+ status = errno_to_portable(errno);
+ } else if ((size_t)ret == len) {
+ status = SSH2_FX_OK;
+ handle_update_write(handle, ret);
+ } else {
+ debug2("nothing at all written");
+ status = SSH2_FX_FAILURE;
+ }
+ }
+ }
+ send_status(id, status);
+ free(data);
+}
+
+static void
+process_do_stat(u_int32_t id, int do_lstat)
+{
+ Attrib a;
+ struct stat st;
+ char *name;
+ int r, status = SSH2_FX_FAILURE;
+
+ if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: %sstat", id, do_lstat ? "l" : "");
+ verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
+ r = do_lstat ? lstat(name, &st) : stat(name, &st);
+ if (r < 0) {
+ status = errno_to_portable(errno);
+ } else {
+ stat_to_attrib(&st, &a);
+ send_attrib(id, &a);
+ status = SSH2_FX_OK;
+ }
+ if (status != SSH2_FX_OK)
+ send_status(id, status);
+ free(name);
+}
+
+static void
+process_stat(u_int32_t id)
+{
+ process_do_stat(id, 0);
+}
+
+static void
+process_lstat(u_int32_t id)
+{
+ process_do_stat(id, 1);
+}
+
+static void
+process_fstat(u_int32_t id)
+{
+ Attrib a;
+ struct stat st;
+ int fd, r, handle, status = SSH2_FX_FAILURE;
+
+ if ((r = get_handle(iqueue, &handle)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ debug("request %u: fstat \"%s\" (handle %u)",
+ id, handle_to_name(handle), handle);
+ fd = handle_to_fd(handle);
+ if (fd >= 0) {
+ r = fstat(fd, &st);
+ if (r < 0) {
+ status = errno_to_portable(errno);
+ } else {
+ stat_to_attrib(&st, &a);
+ send_attrib(id, &a);
+ status = SSH2_FX_OK;
+ }
+ }
+ if (status != SSH2_FX_OK)
+ send_status(id, status);
+}
+
+static struct timeval *
+attrib_to_tv(const Attrib *a)
+{
+ static struct timeval tv[2];
+
+ tv[0].tv_sec = a->atime;
+ tv[0].tv_usec = 0;
+ tv[1].tv_sec = a->mtime;
+ tv[1].tv_usec = 0;
+ return tv;
+}
+
+static void
+process_setstat(u_int32_t id)
+{
+ Attrib a;
+ char *name;
+ int r, status = SSH2_FX_OK;
+
+ if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
+ (r = decode_attrib(iqueue, &a)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug("request %u: setstat name \"%s\"", id, name);
+ if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
+ logit("set \"%s\" size %llu",
+ name, (unsigned long long)a.size);
+ r = truncate(name, a.size);
+ if (r == -1)
+ status = errno_to_portable(errno);
+ }
+ if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
+ logit("set \"%s\" mode %04o", name, a.perm);
+ r = chmod(name, a.perm & 07777);
+ if (r == -1)
+ status = errno_to_portable(errno);
+ }
+ if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
+ char buf[64];
+ time_t t = a.mtime;
+
+ strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
+ localtime(&t));
+ logit("set \"%s\" modtime %s", name, buf);
+ r = utimes(name, attrib_to_tv(&a));
+ if (r == -1)
+ status = errno_to_portable(errno);
+ }
+ if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
+ logit("set \"%s\" owner %lu group %lu", name,
+ (u_long)a.uid, (u_long)a.gid);
+ r = chown(name, a.uid, a.gid);
+ if (r == -1)
+ status = errno_to_portable(errno);
+ }
+ send_status(id, status);
+ free(name);
+}
+
+static void
+process_fsetstat(u_int32_t id)
+{
+ Attrib a;
+ int handle, fd, r;
+ int status = SSH2_FX_OK;
+
+ if ((r = get_handle(iqueue, &handle)) != 0 ||
+ (r = decode_attrib(iqueue, &a)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug("request %u: fsetstat handle %d", id, handle);
+ fd = handle_to_fd(handle);
+ if (fd < 0)
+ status = SSH2_FX_FAILURE;
+ else {
+ char *name = handle_to_name(handle);
+
+ if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
+ logit("set \"%s\" size %llu",
+ name, (unsigned long long)a.size);
+ r = ftruncate(fd, a.size);
+ if (r == -1)
+ status = errno_to_portable(errno);
+ }
+ if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
+ logit("set \"%s\" mode %04o", name, a.perm);
+#ifdef HAVE_FCHMOD
+ r = fchmod(fd, a.perm & 07777);
+#else
+ r = chmod(name, a.perm & 07777);
+#endif
+ if (r == -1)
+ status = errno_to_portable(errno);
+ }
+ if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
+ char buf[64];
+ time_t t = a.mtime;
+
+ strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
+ localtime(&t));
+ logit("set \"%s\" modtime %s", name, buf);
+#ifdef HAVE_FUTIMES
+ r = futimes(fd, attrib_to_tv(&a));
+#else
+ r = utimes(name, attrib_to_tv(&a));
+#endif
+ if (r == -1)
+ status = errno_to_portable(errno);
+ }
+ if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
+ logit("set \"%s\" owner %lu group %lu", name,
+ (u_long)a.uid, (u_long)a.gid);
+#ifdef HAVE_FCHOWN
+ r = fchown(fd, a.uid, a.gid);
+#else
+ r = chown(name, a.uid, a.gid);
+#endif
+ if (r == -1)
+ status = errno_to_portable(errno);
+ }
+ }
+ send_status(id, status);
+}
+
+static void
+process_opendir(u_int32_t id)
+{
+ DIR *dirp = NULL;
+ char *path;
+ int r, handle, status = SSH2_FX_FAILURE;
+
+ if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: opendir", id);
+ logit("opendir \"%s\"", path);
+ dirp = opendir(path);
+ if (dirp == NULL) {
+ status = errno_to_portable(errno);
+ } else {
+ handle = handle_new(HANDLE_DIR, path, 0, 0, dirp);
+ if (handle < 0) {
+ closedir(dirp);
+ } else {
+ send_handle(id, handle);
+ status = SSH2_FX_OK;
+ }
+
+ }
+ if (status != SSH2_FX_OK)
+ send_status(id, status);
+ free(path);
+}
+
+static void
+process_readdir(u_int32_t id)
+{
+ DIR *dirp;
+ struct dirent *dp;
+ char *path;
+ int r, handle;
+
+ if ((r = get_handle(iqueue, &handle)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug("request %u: readdir \"%s\" (handle %d)", id,
+ handle_to_name(handle), handle);
+ dirp = handle_to_dir(handle);
+ path = handle_to_name(handle);
+ if (dirp == NULL || path == NULL) {
+ send_status(id, SSH2_FX_FAILURE);
+ } else {
+ struct stat st;
+ char pathname[PATH_MAX];
+ Stat *stats;
+ int nstats = 10, count = 0, i;
+
+ stats = xcalloc(nstats, sizeof(Stat));
+ while ((dp = readdir(dirp)) != NULL) {
+ if (count >= nstats) {
+ nstats *= 2;
+ stats = xreallocarray(stats, nstats, sizeof(Stat));
+ }
+/* XXX OVERFLOW ? */
+ snprintf(pathname, sizeof pathname, "%s%s%s", path,
+ strcmp(path, "/") ? "/" : "", dp->d_name);
+ if (lstat(pathname, &st) < 0)
+ continue;
+ stat_to_attrib(&st, &(stats[count].attrib));
+ stats[count].name = xstrdup(dp->d_name);
+ stats[count].long_name = ls_file(dp->d_name, &st, 0, 0);
+ count++;
+ /* send up to 100 entries in one message */
+ /* XXX check packet size instead */
+ if (count == 100)
+ break;
+ }
+ if (count > 0) {
+ send_names(id, count, stats);
+ for (i = 0; i < count; i++) {
+ free(stats[i].name);
+ free(stats[i].long_name);
+ }
+ } else {
+ send_status(id, SSH2_FX_EOF);
+ }
+ free(stats);
+ }
+}
+
+static void
+process_remove(u_int32_t id)
+{
+ char *name;
+ int r, status = SSH2_FX_FAILURE;
+
+ if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: remove", id);
+ logit("remove name \"%s\"", name);
+ r = unlink(name);
+ status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+ send_status(id, status);
+ free(name);
+}
+
+static void
+process_mkdir(u_int32_t id)
+{
+ Attrib a;
+ char *name;
+ int r, mode, status = SSH2_FX_FAILURE;
+
+ if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
+ (r = decode_attrib(iqueue, &a)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
+ a.perm & 07777 : 0777;
+ debug3("request %u: mkdir", id);
+ logit("mkdir name \"%s\" mode 0%o", name, mode);
+ r = mkdir(name, mode);
+ status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+ send_status(id, status);
+ free(name);
+}
+
+static void
+process_rmdir(u_int32_t id)
+{
+ char *name;
+ int r, status;
+
+ if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: rmdir", id);
+ logit("rmdir name \"%s\"", name);
+ r = rmdir(name);
+ status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+ send_status(id, status);
+ free(name);
+}
+
+static void
+process_realpath(u_int32_t id)
+{
+ char resolvedname[PATH_MAX];
+ char *path;
+ int r;
+
+ if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ if (path[0] == '\0') {
+ free(path);
+ path = xstrdup(".");
+ }
+ debug3("request %u: realpath", id);
+ verbose("realpath \"%s\"", path);
+ if (realpath(path, resolvedname) == NULL) {
+ send_status(id, errno_to_portable(errno));
+ } else {
+ Stat s;
+ attrib_clear(&s.attrib);
+ s.name = s.long_name = resolvedname;
+ send_names(id, 1, &s);
+ }
+ free(path);
+}
+
+static void
+process_rename(u_int32_t id)
+{
+ char *oldpath, *newpath;
+ int r, status;
+ struct stat sb;
+
+ if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
+ (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: rename", id);
+ logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
+ status = SSH2_FX_FAILURE;
+ if (lstat(oldpath, &sb) == -1)
+ status = errno_to_portable(errno);
+ else if (S_ISREG(sb.st_mode)) {
+ /* Race-free rename of regular files */
+ if (link(oldpath, newpath) == -1) {
+ if (errno == EOPNOTSUPP || errno == ENOSYS
+#ifdef EXDEV
+ || errno == EXDEV
+#endif
+#ifdef LINK_OPNOTSUPP_ERRNO
+ || errno == LINK_OPNOTSUPP_ERRNO
+#endif
+ ) {
+ struct stat st;
+
+ /*
+ * fs doesn't support links, so fall back to
+ * stat+rename. This is racy.
+ */
+ if (stat(newpath, &st) == -1) {
+ if (rename(oldpath, newpath) == -1)
+ status =
+ errno_to_portable(errno);
+ else
+ status = SSH2_FX_OK;
+ }
+ } else {
+ status = errno_to_portable(errno);
+ }
+ } else if (unlink(oldpath) == -1) {
+ status = errno_to_portable(errno);
+ /* clean spare link */
+ unlink(newpath);
+ } else
+ status = SSH2_FX_OK;
+ } else if (stat(newpath, &sb) == -1) {
+ if (rename(oldpath, newpath) == -1)
+ status = errno_to_portable(errno);
+ else
+ status = SSH2_FX_OK;
+ }
+ send_status(id, status);
+ free(oldpath);
+ free(newpath);
+}
+
+static void
+process_readlink(u_int32_t id)
+{
+ int r, len;
+ char buf[PATH_MAX];
+ char *path;
+
+ if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: readlink", id);
+ verbose("readlink \"%s\"", path);
+ if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
+ send_status(id, errno_to_portable(errno));
+ else {
+ Stat s;
+
+ buf[len] = '\0';
+ attrib_clear(&s.attrib);
+ s.name = s.long_name = buf;
+ send_names(id, 1, &s);
+ }
+ free(path);
+}
+
+static void
+process_symlink(u_int32_t id)
+{
+ char *oldpath, *newpath;
+ int r, status;
+
+ if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
+ (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: symlink", id);
+ logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
+ /* this will fail if 'newpath' exists */
+ r = symlink(oldpath, newpath);
+ status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+ send_status(id, status);
+ free(oldpath);
+ free(newpath);
+}
+
+static void
+process_extended_posix_rename(u_int32_t id)
+{
+ char *oldpath, *newpath;
+ int r, status;
+
+ if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
+ (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: posix-rename", id);
+ logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath);
+ r = rename(oldpath, newpath);
+ status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+ send_status(id, status);
+ free(oldpath);
+ free(newpath);
+}
+
+static void
+process_extended_statvfs(u_int32_t id)
+{
+ char *path;
+ struct statvfs st;
+ int r;
+
+ if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ debug3("request %u: statvfs", id);
+ logit("statvfs \"%s\"", path);
+
+ if (statvfs(path, &st) != 0)
+ send_status(id, errno_to_portable(errno));
+ else
+ send_statvfs(id, &st);
+ free(path);
+}
+
+static void
+process_extended_fstatvfs(u_int32_t id)
+{
+ int r, handle, fd;
+ struct statvfs st;
+
+ if ((r = get_handle(iqueue, &handle)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ debug("request %u: fstatvfs \"%s\" (handle %u)",
+ id, handle_to_name(handle), handle);
+ if ((fd = handle_to_fd(handle)) < 0) {
+ send_status(id, SSH2_FX_FAILURE);
+ return;
+ }
+ if (fstatvfs(fd, &st) != 0)
+ send_status(id, errno_to_portable(errno));
+ else
+ send_statvfs(id, &st);
+}
+
+static void
+process_extended_hardlink(u_int32_t id)
+{
+ char *oldpath, *newpath;
+ int r, status;
+
+ if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
+ (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ debug3("request %u: hardlink", id);
+ logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath);
+ r = link(oldpath, newpath);
+ status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+ send_status(id, status);
+ free(oldpath);
+ free(newpath);
+}
+
+static void
+process_extended_fsync(u_int32_t id)
+{
+ int handle, fd, r, status = SSH2_FX_OP_UNSUPPORTED;
+
+ if ((r = get_handle(iqueue, &handle)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ debug3("request %u: fsync (handle %u)", id, handle);
+ verbose("fsync \"%s\"", handle_to_name(handle));
+ if ((fd = handle_to_fd(handle)) < 0)
+ status = SSH2_FX_NO_SUCH_FILE;
+ else if (handle_is_ok(handle, HANDLE_FILE)) {
+ r = fsync(fd);
+ status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+ }
+ send_status(id, status);
+}
+
+static void
+process_extended(u_int32_t id)
+{
+ char *request;
+ int i, r;
+
+ if ((r = sshbuf_get_cstring(iqueue, &request, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ for (i = 0; extended_handlers[i].handler != NULL; i++) {
+ if (strcmp(request, extended_handlers[i].ext_name) == 0) {
+ if (!request_permitted(&extended_handlers[i]))
+ send_status(id, SSH2_FX_PERMISSION_DENIED);
+ else
+ extended_handlers[i].handler(id);
+ break;
+ }
+ }
+ if (extended_handlers[i].handler == NULL) {
+ error("Unknown extended request \"%.100s\"", request);
+ send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */
+ }
+ free(request);
+}
+
+/* stolen from ssh-agent */
+
+static void
+process(void)
+{
+ u_int msg_len;
+ u_int buf_len;
+ u_int consumed;
+ u_char type;
+ const u_char *cp;
+ int i, r;
+ u_int32_t id;
+
+ buf_len = sshbuf_len(iqueue);
+ if (buf_len < 5)
+ return; /* Incomplete message. */
+ cp = sshbuf_ptr(iqueue);
+ msg_len = get_u32(cp);
+ if (msg_len > SFTP_MAX_MSG_LENGTH) {
+ error("bad message from %s local user %s",
+ client_addr, pw->pw_name);
+ sftp_server_cleanup_exit(11);
+ }
+ if (buf_len < msg_len + 4)
+ return;
+ if ((r = sshbuf_consume(iqueue, 4)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ buf_len -= 4;
+ if ((r = sshbuf_get_u8(iqueue, &type)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ switch (type) {
+ case SSH2_FXP_INIT:
+ process_init();
+ init_done = 1;
+ break;
+ case SSH2_FXP_EXTENDED:
+ if (!init_done)
+ fatal("Received extended request before init");
+ if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ process_extended(id);
+ break;
+ default:
+ if (!init_done)
+ fatal("Received %u request before init", type);
+ if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ for (i = 0; handlers[i].handler != NULL; i++) {
+ if (type == handlers[i].type) {
+ if (!request_permitted(&handlers[i])) {
+ send_status(id,
+ SSH2_FX_PERMISSION_DENIED);
+ } else {
+ handlers[i].handler(id);
+ }
+ break;
+ }
+ }
+ if (handlers[i].handler == NULL)
+ error("Unknown message %u", type);
+ }
+ /* discard the remaining bytes from the current packet */
+ if (buf_len < sshbuf_len(iqueue)) {
+ error("iqueue grew unexpectedly");
+ sftp_server_cleanup_exit(255);
+ }
+ consumed = buf_len - sshbuf_len(iqueue);
+ if (msg_len < consumed) {
+ error("msg_len %u < consumed %u", msg_len, consumed);
+ sftp_server_cleanup_exit(255);
+ }
+ if (msg_len > consumed &&
+ (r = sshbuf_consume(iqueue, msg_len - consumed)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+}
+
+/* Cleanup handler that logs active handles upon normal exit */
+void
+sftp_server_cleanup_exit(int i)
+{
+ if (pw != NULL && client_addr != NULL) {
+ handle_log_exit();
+ logit("session closed for local user %s from [%s]",
+ pw->pw_name, client_addr);
+ }
+ _exit(i);
+}
+
+static void
+sftp_server_usage(void)
+{
+ extern char *__progname;
+
+ fprintf(stderr,
+ "usage: %s [-ehR] [-d start_directory] [-f log_facility] "
+ "[-l log_level]\n\t[-P blacklisted_requests] "
+ "[-p whitelisted_requests] [-u umask]\n"
+ " %s -Q protocol_feature\n",
+ __progname, __progname);
+ exit(1);
+}
+
+int
+sftp_server_main(int argc, char **argv, struct passwd *user_pw)
+{
+ fd_set *rset, *wset;
+ int i, r, in, out, max, ch, skipargs = 0, log_stderr = 0;
+ ssize_t len, olen, set_size;
+ SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
+ char *cp, *homedir = NULL, uidstr[32], buf[4*4096];
+ long mask;
+
+ extern char *optarg;
+ extern char *__progname;
+
+ ssh_malloc_init(); /* must be called before any mallocs */
+ __progname = ssh_get_progname(argv[0]);
+ log_init(__progname, log_level, log_facility, log_stderr);
+
+ pw = pwcopy(user_pw);
+
+ while (!skipargs && (ch = getopt(argc, argv,
+ "d:f:l:P:p:Q:u:cehR")) != -1) {
+ switch (ch) {
+ case 'Q':
+ if (strcasecmp(optarg, "requests") != 0) {
+ fprintf(stderr, "Invalid query type\n");
+ exit(1);
+ }
+ for (i = 0; handlers[i].handler != NULL; i++)
+ printf("%s\n", handlers[i].name);
+ for (i = 0; extended_handlers[i].handler != NULL; i++)
+ printf("%s\n", extended_handlers[i].name);
+ exit(0);
+ break;
+ case 'R':
+ readonly = 1;
+ break;
+ case 'c':
+ /*
+ * Ignore all arguments if we are invoked as a
+ * shell using "sftp-server -c command"
+ */
+ skipargs = 1;
+ break;
+ case 'e':
+ log_stderr = 1;
+ break;
+ case 'l':
+ log_level = log_level_number(optarg);
+ if (log_level == SYSLOG_LEVEL_NOT_SET)
+ error("Invalid log level \"%s\"", optarg);
+ break;
+ case 'f':
+ log_facility = log_facility_number(optarg);
+ if (log_facility == SYSLOG_FACILITY_NOT_SET)
+ error("Invalid log facility \"%s\"", optarg);
+ break;
+ case 'd':
+ cp = tilde_expand_filename(optarg, user_pw->pw_uid);
+ snprintf(uidstr, sizeof(uidstr), "%llu",
+ (unsigned long long)pw->pw_uid);
+ homedir = percent_expand(cp, "d", user_pw->pw_dir,
+ "u", user_pw->pw_name, "U", uidstr, (char *)NULL);
+ free(cp);
+ break;
+ case 'p':
+ if (request_whitelist != NULL)
+ fatal("Permitted requests already set");
+ request_whitelist = xstrdup(optarg);
+ break;
+ case 'P':
+ if (request_blacklist != NULL)
+ fatal("Refused requests already set");
+ request_blacklist = xstrdup(optarg);
+ break;
+ case 'u':
+ errno = 0;
+ mask = strtol(optarg, &cp, 8);
+ if (mask < 0 || mask > 0777 || *cp != '\0' ||
+ cp == optarg || (mask == 0 && errno != 0))
+ fatal("Invalid umask \"%s\"", optarg);
+ (void)umask((mode_t)mask);
+ break;
+ case 'h':
+ default:
+ sftp_server_usage();
+ }
+ }
+
+ log_init(__progname, log_level, log_facility, log_stderr);
+
+ /*
+ * On platforms where we can, avoid making /proc/self/{mem,maps}
+ * available to the user so that sftp access doesn't automatically
+ * imply arbitrary code execution access that will break
+ * restricted configurations.
+ */
+ platform_disable_tracing(1); /* strict */
+
+ /* Drop any fine-grained privileges we don't need */
+ platform_pledge_sftp_server();
+
+ if ((cp = getenv("SSH_CONNECTION")) != NULL) {
+ client_addr = xstrdup(cp);
+ if ((cp = strchr(client_addr, ' ')) == NULL) {
+ error("Malformed SSH_CONNECTION variable: \"%s\"",
+ getenv("SSH_CONNECTION"));
+ sftp_server_cleanup_exit(255);
+ }
+ *cp = '\0';
+ } else
+ client_addr = xstrdup("UNKNOWN");
+
+ logit("session opened for local user %s from [%s]",
+ pw->pw_name, client_addr);
+
+ in = STDIN_FILENO;
+ out = STDOUT_FILENO;
+
+#ifdef HAVE_CYGWIN
+ setmode(in, O_BINARY);
+ setmode(out, O_BINARY);
+#endif
+
+ max = 0;
+ if (in > max)
+ max = in;
+ if (out > max)
+ max = out;
+
+ if ((iqueue = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+ if ((oqueue = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+
+ rset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask));
+ wset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask));
+
+ if (homedir != NULL) {
+ if (chdir(homedir) != 0) {
+ error("chdir to \"%s\" failed: %s", homedir,
+ strerror(errno));
+ }
+ }
+
+ set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
+ for (;;) {
+ memset(rset, 0, set_size);
+ memset(wset, 0, set_size);
+
+ /*
+ * Ensure that we can read a full buffer and handle
+ * the worst-case length packet it can generate,
+ * otherwise apply backpressure by stopping reads.
+ */
+ if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 &&
+ (r = sshbuf_check_reserve(oqueue,
+ SFTP_MAX_MSG_LENGTH)) == 0)
+ FD_SET(in, rset);
+ else if (r != SSH_ERR_NO_BUFFER_SPACE)
+ fatal("%s: sshbuf_check_reserve failed: %s",
+ __func__, ssh_err(r));
+
+ olen = sshbuf_len(oqueue);
+ if (olen > 0)
+ FD_SET(out, wset);
+
+ if (select(max+1, rset, wset, NULL, NULL) < 0) {
+ if (errno == EINTR)
+ continue;
+ error("select: %s", strerror(errno));
+ sftp_server_cleanup_exit(2);
+ }
+
+ /* copy stdin to iqueue */
+ if (FD_ISSET(in, rset)) {
+ len = read(in, buf, sizeof buf);
+ if (len == 0) {
+ debug("read eof");
+ sftp_server_cleanup_exit(0);
+ } else if (len < 0) {
+ error("read: %s", strerror(errno));
+ sftp_server_cleanup_exit(1);
+ } else if ((r = sshbuf_put(iqueue, buf, len)) != 0) {
+ fatal("%s: buffer error: %s",
+ __func__, ssh_err(r));
+ }
+ }
+ /* send oqueue to stdout */
+ if (FD_ISSET(out, wset)) {
+ len = write(out, sshbuf_ptr(oqueue), olen);
+ if (len < 0) {
+ error("write: %s", strerror(errno));
+ sftp_server_cleanup_exit(1);
+ } else if ((r = sshbuf_consume(oqueue, len)) != 0) {
+ fatal("%s: buffer error: %s",
+ __func__, ssh_err(r));
+ }
+ }
+
+ /*
+ * Process requests from client if we can fit the results
+ * into the output buffer, otherwise stop processing input
+ * and let the output queue drain.
+ */
+ r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH);
+ if (r == 0)
+ process();
+ else if (r != SSH_ERR_NO_BUFFER_SPACE)
+ fatal("%s: sshbuf_check_reserve: %s",
+ __func__, ssh_err(r));
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 12:52:02 +0000