/* * 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" RCSID("$OpenBSD: sftp-server.c,v 1.45 2004/02/19 21:15:04 markus Exp $"); #include "buffer.h" #include "bufaux.h" #include "getput.h" #include "log.h" #include "xmalloc.h" #include "sftp.h" #include "sftp-common.h" /* helper */ #define get_int64() buffer_get_int64(&iqueue); #define get_int() buffer_get_int(&iqueue); #define get_string(lenp) buffer_get_string(&iqueue, lenp); #define TRACE debug /* input and output queue */ Buffer iqueue; Buffer oqueue; /* Version of client */ int version; /* portable attributes, etc. */ typedef struct Stat Stat; struct Stat { char *name; char *long_name; Attrib attrib; }; 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; 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_CREAT) flags |= O_CREAT; if (pflags & SSH2_FXF_TRUNC) flags |= O_TRUNC; if (pflags & SSH2_FXF_EXCL) flags |= O_EXCL; return flags; } static Attrib * get_attrib(void) { return decode_attrib(&iqueue); } /* handle handles */ typedef struct Handle Handle; struct Handle { int use; DIR *dirp; int fd; char *name; }; enum { HANDLE_UNUSED, HANDLE_DIR, HANDLE_FILE }; Handle handles[100]; static void handle_init(void) { int i; for (i = 0; i < sizeof(handles)/sizeof(Handle); i++) handles[i].use = HANDLE_UNUSED; } static int handle_new(int use, const char *name, int fd, DIR *dirp) { int i; for (i = 0; i < sizeof(handles)/sizeof(Handle); i++) { if (handles[i].use == HANDLE_UNUSED) { handles[i].use = use; handles[i].dirp = dirp; handles[i].fd = fd; handles[i].name = xstrdup(name); return i; } } return -1; } static int handle_is_ok(int i, int type) { return i >= 0 && i < sizeof(handles)/sizeof(Handle) && handles[i].use == type; } static int handle_to_string(int handle, char **stringp, int *hlenp) { if (stringp == NULL || hlenp == NULL) return -1; *stringp = xmalloc(sizeof(int32_t)); PUT_32BIT(*stringp, handle); *hlenp = sizeof(int32_t); return 0; } static int handle_from_string(const char *handle, u_int hlen) { int val; if (hlen != sizeof(int32_t)) return -1; val = GET_32BIT(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_close(int handle) { int ret = -1; if (handle_is_ok(handle, HANDLE_FILE)) { ret = close(handles[handle].fd); handles[handle].use = HANDLE_UNUSED; xfree(handles[handle].name); } else if (handle_is_ok(handle, HANDLE_DIR)) { ret = closedir(handles[handle].dirp); handles[handle].use = HANDLE_UNUSED; xfree(handles[handle].name); } else { errno = ENOENT; } return ret; } static int get_handle(void) { char *handle; int val = -1; u_int hlen; handle = get_string(&hlen); if (hlen < 256) val = handle_from_string(handle, hlen); xfree(handle); return val; } /* send replies */ static void send_msg(Buffer *m) { int mlen = buffer_len(m); buffer_put_int(&oqueue, mlen); buffer_append(&oqueue, buffer_ptr(m), mlen); buffer_consume(m, mlen); } static void send_status(u_int32_t id, u_int32_t error) { Buffer msg; 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 */ }; TRACE("sent status id %u error %u", id, error); buffer_init(&msg); buffer_put_char(&msg, SSH2_FXP_STATUS); buffer_put_int(&msg, id); buffer_put_int(&msg, error); if (version >= 3) { buffer_put_cstring(&msg, status_messages[MIN(error,SSH2_FX_MAX)]); buffer_put_cstring(&msg, ""); } send_msg(&msg); buffer_free(&msg); } static void send_data_or_handle(char type, u_int32_t id, const char *data, int dlen) { Buffer msg; buffer_init(&msg); buffer_put_char(&msg, type); buffer_put_int(&msg, id); buffer_put_string(&msg, data, dlen); send_msg(&msg); buffer_free(&msg); } static void send_data(u_int32_t id, const char *data, int dlen) { TRACE("sent data id %u len %d", id, dlen); send_data_or_handle(SSH2_FXP_DATA, id, data, dlen); } static void send_handle(u_int32_t id, int handle) { char *string; int hlen; handle_to_string(handle, &string, &hlen); TRACE("sent handle id %u handle %d", id, handle); send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen); xfree(string); } static void send_names(u_int32_t id, int count, const Stat *stats) { Buffer msg; int i; buffer_init(&msg); buffer_put_char(&msg, SSH2_FXP_NAME); buffer_put_int(&msg, id); buffer_put_int(&msg, count); TRACE("sent names id %u count %d", id, count); for (i = 0; i < count; i++) { buffer_put_cstring(&msg, stats[i].name); buffer_put_cstring(&msg, stats[i].long_name); encode_attrib(&msg, &stats[i].attrib); } send_msg(&msg); buffer_free(&msg); } static void send_attrib(u_int32_t id, const Attrib *a) { Buffer msg; TRACE("sent attrib id %u have 0x%x", id, a->flags); buffer_init(&msg); buffer_put_char(&msg, SSH2_FXP_ATTRS); buffer_put_int(&msg, id); encode_attrib(&msg, a); send_msg(&msg); buffer_free(&msg); } /* parse incoming */ static void process_init(void) { Buffer msg; version = get_int(); TRACE("client version %d", version); buffer_init(&msg); buffer_put_char(&msg, SSH2_FXP_VERSION); buffer_put_int(&msg, SSH2_FILEXFER_VERSION); send_msg(&msg); buffer_free(&msg); } static void process_open(void) { u_int32_t id, pflags; Attrib *a; char *name; int handle, fd, flags, mode, status = SSH2_FX_FAILURE; id = get_int(); name = get_string(NULL); pflags = get_int(); /* portable flags */ a = get_attrib(); flags = flags_from_portable(pflags); mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a->perm : 0666; TRACE("open id %u name %s flags %d mode 0%o", id, name, pflags, mode); fd = open(name, flags, mode); if (fd < 0) { status = errno_to_portable(errno); } else { handle = handle_new(HANDLE_FILE, name, fd, NULL); if (handle < 0) { close(fd); } else { send_handle(id, handle); status = SSH2_FX_OK; } } if (status != SSH2_FX_OK) send_status(id, status); xfree(name); } static void process_close(void) { u_int32_t id; int handle, ret, status = SSH2_FX_FAILURE; id = get_int(); handle = get_handle(); TRACE("close id %u handle %d", id, handle); ret = handle_close(handle); status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK; send_status(id, status); } static void process_read(void) { char buf[64*1024]; u_int32_t id, len; int handle, fd, ret, status = SSH2_FX_FAILURE; u_int64_t off; id = get_int(); handle = get_handle(); off = get_int64(); len = get_int(); TRACE("read id %u handle %d off %llu len %d", id, handle, (unsigned long long)off, len); if (len > sizeof buf) { len = sizeof buf; logit("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; } } } if (status != SSH2_FX_OK) send_status(id, status); } static void process_write(void) { u_int32_t id; u_int64_t off; u_int len; int handle, fd, ret, status = SSH2_FX_FAILURE; char *data; id = get_int(); handle = get_handle(); off = get_int64(); data = get_string(&len); TRACE("write id %u handle %d off %llu len %d", id, handle, (unsigned long long)off, len); fd = handle_to_fd(handle); if (fd >= 0) { if (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 == -1) { error("process_write: write failed"); status = errno_to_portable(errno); } else if (ret == len) { status = SSH2_FX_OK; } else { logit("nothing at all written"); } } } send_status(id, status); xfree(data); } static void process_do_stat(int do_lstat) { Attrib a; struct stat st; u_int32_t id; char *name; int ret, status = SSH2_FX_FAILURE; id = get_int(); name = get_string(NULL); TRACE("%sstat id %u name %s", do_lstat ? "l" : "", id, name); ret = do_lstat ? lstat(name, &st) : stat(name, &st); if (ret < 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); xfree(name); } static void process_stat(void) { process_do_stat(0); } static void process_lstat(void) { process_do_stat(1); } static void process_fstat(void) { Attrib a; struct stat st; u_int32_t id; int fd, ret, handle, status = SSH2_FX_FAILURE; id = get_int(); handle = get_handle(); TRACE("fstat id %u handle %d", id, handle); fd = handle_to_fd(handle); if (fd >= 0) { ret = fstat(fd, &st); if (ret < 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(void) { Attrib *a; u_int32_t id; char *name; int status = SSH2_FX_OK, ret; id = get_int(); name = get_string(NULL); a = get_attrib(); TRACE("setstat id %u name %s", id, name); if (a->flags & SSH2_FILEXFER_ATTR_SIZE) { ret = truncate(name, a->size); if (ret == -1) status = errno_to_portable(errno); } if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) { ret = chmod(name, a->perm & 0777); if (ret == -1) status = errno_to_portable(errno); } if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) { ret = utimes(name, attrib_to_tv(a)); if (ret == -1) status = errno_to_portable(errno); } if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) { ret = chown(name, a->uid, a->gid); if (ret == -1) status = errno_to_portable(errno); } send_status(id, status); xfree(name); } static void process_fsetstat(void) { Attrib *a; u_int32_t id; int handle, fd, ret; int status = SSH2_FX_OK; id = get_int(); handle = get_handle(); a = get_attrib(); TRACE("fsetstat id %u handle %d", id, handle); fd = handle_to_fd(handle); if (fd < 0) { status = SSH2_FX_FAILURE; } else { if (a->flags & SSH2_FILEXFER_ATTR_SIZE) { ret = ftruncate(fd, a->size); if (ret == -1) status = errno_to_portable(errno); } if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) { ret = fchmod(fd, a->perm & 0777); if (ret == -1) status = errno_to_portable(errno); } if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) { ret = futimes(fd, attrib_to_tv(a)); if (ret == -1) status = errno_to_portable(errno); } if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) { ret = fchown(fd, a->uid, a->gid); if (ret == -1) status = errno_to_portable(errno); } } send_status(id, status); } static void process_opendir(void) { DIR *dirp = NULL; char *path; int handle, status = SSH2_FX_FAILURE; u_int32_t id; id = get_int(); path = get_string(NULL); TRACE("opendir id %u path %s", id, path); dirp = opendir(path); if (dirp == NULL) { status = errno_to_portable(errno); } else { handle = handle_new(HANDLE_DIR, path, 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); xfree(path); } static void process_readdir(void) { DIR *dirp; struct dirent *dp; char *path; int handle; u_int32_t id; id = get_int(); handle = get_handle(); TRACE("readdir id %u handle %d", id, 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[1024]; Stat *stats; int nstats = 10, count = 0, i; stats = xmalloc(nstats * sizeof(Stat)); while ((dp = readdir(dirp)) != NULL) { if (count >= nstats) { nstats *= 2; stats = xrealloc(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); 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++) { xfree(stats[i].name); xfree(stats[i].long_name); } } else { send_status(id, SSH2_FX_EOF); } xfree(stats); } } static void process_remove(void) { char *name; u_int32_t id; int status = SSH2_FX_FAILURE; int ret; id = get_int(); name = get_string(NULL); TRACE("remove id %u name %s", id, name); ret = unlink(name); status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK; send_status(id, status); xfree(name); } static void process_mkdir(void) { Attrib *a; u_int32_t id; char *name; int ret, mode, status = SSH2_FX_FAILURE; id = get_int(); name = get_string(NULL); a = get_attrib(); mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a->perm & 0777 : 0777; TRACE("mkdir id %u name %s mode 0%o", id, name, mode); ret = mkdir(name, mode); status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK; send_status(id, status); xfree(name); } static void process_rmdir(void) { u_int32_t id; char *name; int ret, status; id = get_int(); name = get_string(NULL); TRACE("rmdir id %u name %s", id, name); ret = rmdir(name); status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK; send_status(id, status); xfree(name); } static void process_realpath(void) { char resolvedname[MAXPATHLEN]; u_int32_t id; char *path; id = get_int(); path = get_string(NULL); if (path[0] == '\0') { xfree(path); path = xstrdup("."); } TRACE("realpath id %u path %s", id, 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); } xfree(path); } static void process_rename(void) { u_int32_t id; char *oldpath, *newpath; int status; struct stat sb; id = get_int(); oldpath = get_string(NULL); newpath = get_string(NULL); TRACE("rename id %u old %s new %s", id, 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) 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); xfree(oldpath); xfree(newpath); } static void process_readlink(void) { u_int32_t id; int len; char link[MAXPATHLEN]; char *path; id = get_int(); path = get_string(NULL); TRACE("readlink id %u path %s", id, path); if ((len = readlink(path, link, sizeof(link) - 1)) == -1) send_status(id, errno_to_portable(errno)); else { Stat s; link[len] = '\0'; attrib_clear(&s.attrib); s.name = s.long_name = link; send_names(id, 1, &s); } xfree(path); } static void process_symlink(void) { u_int32_t id; char *oldpath, *newpath; int ret, status; id = get_int(); oldpath = get_string(NULL); newpath = get_string(NULL); TRACE("symlink id %u old %s new %s", id, oldpath, newpath); /* this will fail if 'newpath' exists */ ret = symlink(oldpath, newpath); status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK; send_status(id, status); xfree(oldpath); xfree(newpath); } static void process_extended(void) { u_int32_t id; char *request; id = get_int(); request = get_string(NULL); send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */ xfree(request); } /* stolen from ssh-agent */ static void process(void) { u_int msg_len; u_int buf_len; u_int consumed; u_int type; u_char *cp; buf_len = buffer_len(&iqueue); if (buf_len < 5) return; /* Incomplete message. */ cp = buffer_ptr(&iqueue); msg_len = GET_32BIT(cp); if (msg_len > 256 * 1024) { error("bad message "); exit(11); } if (buf_len < msg_len + 4) return; buffer_consume(&iqueue, 4); buf_len -= 4; type = buffer_get_char(&iqueue); switch (type) { case SSH2_FXP_INIT: process_init(); break; case SSH2_FXP_OPEN: process_open(); break; case SSH2_FXP_CLOSE: process_close(); break; case SSH2_FXP_READ: process_read(); break; case SSH2_FXP_WRITE: process_write(); break; case SSH2_FXP_LSTAT: process_lstat(); break; case SSH2_FXP_FSTAT: process_fstat(); break; case SSH2_FXP_SETSTAT: process_setstat(); break; case SSH2_FXP_FSETSTAT: process_fsetstat(); break; case SSH2_FXP_OPENDIR: process_opendir(); break; case SSH2_FXP_READDIR: process_readdir(); break; case SSH2_FXP_REMOVE: process_remove(); break; case SSH2_FXP_MKDIR: process_mkdir(); break; case SSH2_FXP_RMDIR: process_rmdir(); break; case SSH2_FXP_REALPATH: process_realpath(); break; case SSH2_FXP_STAT: process_stat(); break; case SSH2_FXP_RENAME: process_rename(); break; case SSH2_FXP_READLINK: process_readlink(); break; case SSH2_FXP_SYMLINK: process_symlink(); break; case SSH2_FXP_EXTENDED: process_extended(); break; default: error("Unknown message %d", type); break; } /* discard the remaining bytes from the current packet */ if (buf_len < buffer_len(&iqueue)) fatal("iqueue grows"); consumed = buf_len - buffer_len(&iqueue); if (msg_len < consumed) fatal("msg_len %d < consumed %d", msg_len, consumed); if (msg_len > consumed) buffer_consume(&iqueue, msg_len - consumed); } int main(int ac, char **av) { fd_set *rset, *wset; int in, out, max; ssize_t len, olen, set_size; /* XXX should use getopt */ handle_init(); #ifdef DEBUG_SFTP_SERVER log_init("sftp-server", SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 0); #endif in = dup(STDIN_FILENO); out = dup(STDOUT_FILENO); max = 0; if (in > max) max = in; if (out > max) max = out; buffer_init(&iqueue); buffer_init(&oqueue); set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask); rset = (fd_set *)xmalloc(set_size); wset = (fd_set *)xmalloc(set_size); for (;;) { memset(rset, 0, set_size); memset(wset, 0, set_size); FD_SET(in, rset); olen = buffer_len(&oqueue); if (olen > 0) FD_SET(out, wset); if (select(max+1, rset, wset, NULL, NULL) < 0) { if (errno == EINTR) continue; exit(2); } /* copy stdin to iqueue */ if (FD_ISSET(in, rset)) { char buf[4*4096]; len = read(in, buf, sizeof buf); if (len == 0) { debug("read eof"); exit(0); } else if (len < 0) { error("read error"); exit(1); } else { buffer_append(&iqueue, buf, len); } } /* send oqueue to stdout */ if (FD_ISSET(out, wset)) { len = write(out, buffer_ptr(&oqueue), olen); if (len < 0) { error("write error"); exit(1); } else { buffer_consume(&oqueue, len); } } /* process requests from client */ process(); } }