From: djm Date: Thu, 31 Mar 2022 03:05:49 +0000 (+0000) Subject: add support for the "corp-data" protocol extension to allow X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=2ac6810fc6db0156c6957b3b5bae045e00fe9437;p=openbsd add support for the "corp-data" protocol extension to allow server-side copies to be performed without having to go via the client. Patch by Mike Frysinger, ok dtucker@ --- diff --git a/usr.bin/ssh/PROTOCOL b/usr.bin/ssh/PROTOCOL index 02ea51f46ec..6f195fd49d4 100644 --- a/usr.bin/ssh/PROTOCOL +++ b/usr.bin/ssh/PROTOCOL @@ -492,7 +492,7 @@ This request asks the server to call fsync(2) on an open file handle. string "fsync@openssh.com" string handle -One receiving this request, a server will call fsync(handle_fd) and will +On receiving this request, a server will call fsync(handle_fd) and will respond with a SSH_FXP_STATUS message. This extension is advertised in the SSH_FXP_VERSION hello with version @@ -576,6 +576,43 @@ Its reply is the same format as that of SSH2_FXP_REALPATH. This extension is advertised in the SSH_FXP_VERSION hello with version "1". +4.10. sftp: Extension request "copy-data" + +This request asks the server to copy data from one open file handle and +write it to a different open file handle. This avoids needing to transfer +the data across the network twice (a download followed by an upload). + + byte SSH_FXP_EXTENDED + uint32 id + string "copy-data" + string read-from-handle + uint64 read-from-offset + uint64 read-data-length + string write-to-handle + uint64 write-to-offset + +The server will copy read-data-length bytes starting from +read-from-offset from the read-from-handle and write them to +write-to-handle starting from write-to-offset, and then respond with a +SSH_FXP_STATUS message. + +It's equivalent to issuing a series of SSH_FXP_READ requests on +read-from-handle and a series of requests of SSH_FXP_WRITE on +write-to-handle. + +If read-from-handle and write-to-handle are the same, the server will +fail the request and respond with a SSH_FX_INVALID_PARAMETER message. + +If read-data-length is 0, then the server will read data from the +read-from-handle until EOF is reached. + +This extension is advertised in the SSH_FXP_VERSION hello with version +"1". + +This request is identical to the "copy-data" request documented in: + +https://tools.ietf.org/html/draft-ietf-secsh-filexfer-extensions-00#section-7 + 5. Miscellaneous changes 5.1 Public key format @@ -612,4 +649,4 @@ master instance and later clients. OpenSSH extends the usual agent protocol. These changes are documented in the PROTOCOL.agent file. -$OpenBSD: PROTOCOL,v 1.43 2021/12/19 22:15:42 djm Exp $ +$OpenBSD: PROTOCOL,v 1.44 2022/03/31 03:05:49 djm Exp $ diff --git a/usr.bin/ssh/sftp-server.c b/usr.bin/ssh/sftp-server.c index 1e2adbe689e..b8cddb42acc 100644 --- a/usr.bin/ssh/sftp-server.c +++ b/usr.bin/ssh/sftp-server.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sftp-server.c,v 1.139 2022/02/01 23:32:51 djm Exp $ */ +/* $OpenBSD: sftp-server.c,v 1.140 2022/03/31 03:05:49 djm Exp $ */ /* * Copyright (c) 2000-2004 Markus Friedl. All rights reserved. * @@ -34,6 +34,7 @@ #include #include +#include "atomicio.h" #include "xmalloc.h" #include "sshbuf.h" #include "ssherr.h" @@ -109,6 +110,7 @@ static void process_extended_fsync(u_int32_t id); static void process_extended_lsetstat(u_int32_t id); static void process_extended_limits(u_int32_t id); static void process_extended_expand(u_int32_t id); +static void process_extended_copy_data(u_int32_t id); static void process_extended(u_int32_t id); struct sftp_handler { @@ -154,6 +156,7 @@ static const struct sftp_handler extended_handlers[] = { { "limits", "limits@openssh.com", 0, process_extended_limits, 0 }, { "expand-path", "expand-path@openssh.com", 0, process_extended_expand, 0 }, + { "copy-data", "copy-data", 0, process_extended_copy_data, 1 }, { NULL, NULL, 0, NULL, 0 } }; @@ -710,6 +713,7 @@ process_init(void) compose_extension(msg, "lsetstat@openssh.com", "1"); compose_extension(msg, "limits@openssh.com", "1"); compose_extension(msg, "expand-path@openssh.com", "1"); + compose_extension(msg, "copy-data", "1"); send_msg(msg); sshbuf_free(msg); @@ -1559,6 +1563,94 @@ process_extended_expand(u_int32_t id) free(path); } +static void +process_extended_copy_data(u_int32_t id) +{ + u_char buf[64*1024]; + int read_handle, read_fd, write_handle, write_fd; + u_int64_t len, read_off, read_len, write_off; + int r, copy_until_eof, status = SSH2_FX_OP_UNSUPPORTED; + size_t ret; + + if ((r = get_handle(iqueue, &read_handle)) != 0 || + (r = sshbuf_get_u64(iqueue, &read_off)) != 0 || + (r = sshbuf_get_u64(iqueue, &read_len)) != 0 || + (r = get_handle(iqueue, &write_handle)) != 0 || + (r = sshbuf_get_u64(iqueue, &write_off)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + + debug("request %u: copy-data from \"%s\" (handle %d) off %llu len %llu " + "to \"%s\" (handle %d) off %llu", + id, handle_to_name(read_handle), read_handle, + (unsigned long long)read_off, (unsigned long long)read_len, + handle_to_name(write_handle), write_handle, + (unsigned long long)write_off); + + /* For read length of 0, we read until EOF. */ + if (read_len == 0) { + read_len = (u_int64_t)-1 - read_off; + copy_until_eof = 1; + } else + copy_until_eof = 0; + + read_fd = handle_to_fd(read_handle); + write_fd = handle_to_fd(write_handle); + + /* Disallow reading & writing to the same handle or same path or dirs */ + if (read_handle == write_handle || read_fd < 0 || write_fd < 0 || + !strcmp(handle_to_name(read_handle), handle_to_name(write_handle))) { + status = SSH2_FX_FAILURE; + goto out; + } + + if (lseek(read_fd, read_off, SEEK_SET) < 0) { + status = errno_to_portable(errno); + error("%s: read_seek failed", __func__); + goto out; + } + + if ((handle_to_flags(write_handle) & O_APPEND) == 0 && + lseek(write_fd, write_off, SEEK_SET) < 0) { + status = errno_to_portable(errno); + error("%s: write_seek failed", __func__); + goto out; + } + + /* Process the request in chunks. */ + while (read_len > 0 || copy_until_eof) { + len = MINIMUM(sizeof(buf), read_len); + read_len -= len; + + ret = atomicio(read, read_fd, buf, len); + if (ret == 0 && errno == EPIPE) { + status = copy_until_eof ? SSH2_FX_OK : SSH2_FX_EOF; + break; + } else if (ret == 0) { + status = errno_to_portable(errno); + error("%s: read failed: %s", __func__, strerror(errno)); + break; + } + len = ret; + handle_update_read(read_handle, len); + + ret = atomicio(vwrite, write_fd, buf, len); + if (ret != len) { + status = errno_to_portable(errno); + error("%s: write failed: %llu != %llu: %s", __func__, + (unsigned long long)ret, (unsigned long long)len, + strerror(errno)); + break; + } + handle_update_write(write_handle, len); + } + + if (read_len == 0) + status = SSH2_FX_OK; + + out: + send_status(id, status); +} + static void process_extended(u_int32_t id) { diff --git a/usr.bin/ssh/sftp-server/Makefile b/usr.bin/ssh/sftp-server/Makefile index c2a08bf32d2..1fde63c8732 100644 --- a/usr.bin/ssh/sftp-server/Makefile +++ b/usr.bin/ssh/sftp-server/Makefile @@ -1,9 +1,9 @@ -# $OpenBSD: Makefile,v 1.13 2019/07/05 04:55:41 djm Exp $ +# $OpenBSD: Makefile,v 1.14 2022/03/31 03:05:49 djm Exp $ .PATH: ${.CURDIR}/.. SRCS= sftp-server.c sftp-common.c sftp-server-main.c sftp-realpath.c -SRCS+= fatal.c +SRCS+= atomicio.c fatal.c SRCS+= ${SRCS_BASE} ${SRCS_UTL} PROG= sftp-server