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[Qemu-block] [PATCH v6] ssh: switch from libssh2 to libssh
From: |
Pino Toscano |
Subject: |
[Qemu-block] [PATCH v6] ssh: switch from libssh2 to libssh |
Date: |
Wed, 5 Jun 2019 23:36:54 +0200 |
Rewrite the implementation of the ssh block driver to use libssh instead
of libssh2. The libssh library has various advantages over libssh2:
- easier API for authentication (for example for using ssh-agent)
- easier API for known_hosts handling
- supports newer types of keys in known_hosts
Use APIs/features available in libssh 0.8 conditionally, to support
older versions (which are not recommended though).
Signed-off-by: Pino Toscano <address@hidden>
---
Changes from v5:
- adapt to newer tracing APIs
- disable ssh compression (mimic what libssh2 does by default)
- use build time checks for libssh 0.8, and use newer APIs directly
Changes from v4:
- fix wrong usages of error_setg/session_error_setg/sftp_error_setg
- fix few return code checks
- remove now-unused parameters in few internal functions
- allow authentication with "none" method
- switch to unsigned int for the port number
- enable TCP_NODELAY on the socket
- fix one reference error message in iotest 207
Changes from v3:
- fix socket cleanup in connect_to_ssh()
- add comments about the socket cleanup
- improve the error reporting (closer to what was with libssh2)
- improve EOF detection on sftp_read()
Changes from v2:
- used again an own fd
- fixed co_yield() implementation
Changes from v1:
- fixed jumbo packets writing
- fixed missing 'err' assignment
- fixed commit message
block/Makefile.objs | 6 +-
block/ssh.c | 610 +++++++++++++++++++------------------
block/trace-events | 14 +-
configure | 62 ++--
tests/qemu-iotests/207.out | 2 +-
5 files changed, 351 insertions(+), 343 deletions(-)
diff --git a/block/Makefile.objs b/block/Makefile.objs
index ae11605c9f..bf01429dd5 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -31,7 +31,7 @@ block-obj-$(CONFIG_CURL) += curl.o
block-obj-$(CONFIG_RBD) += rbd.o
block-obj-$(CONFIG_GLUSTERFS) += gluster.o
block-obj-$(CONFIG_VXHS) += vxhs.o
-block-obj-$(CONFIG_LIBSSH2) += ssh.o
+block-obj-$(CONFIG_LIBSSH) += ssh.o
block-obj-y += accounting.o dirty-bitmap.o
block-obj-y += write-threshold.o
block-obj-y += backup.o
@@ -52,8 +52,8 @@ rbd.o-libs := $(RBD_LIBS)
gluster.o-cflags := $(GLUSTERFS_CFLAGS)
gluster.o-libs := $(GLUSTERFS_LIBS)
vxhs.o-libs := $(VXHS_LIBS)
-ssh.o-cflags := $(LIBSSH2_CFLAGS)
-ssh.o-libs := $(LIBSSH2_LIBS)
+ssh.o-cflags := $(LIBSSH_CFLAGS)
+ssh.o-libs := $(LIBSSH_LIBS)
block-obj-dmg-bz2-$(CONFIG_BZIP2) += dmg-bz2.o
block-obj-$(if $(CONFIG_DMG),m,n) += $(block-obj-dmg-bz2-y)
dmg-bz2.o-libs := $(BZIP2_LIBS)
diff --git a/block/ssh.c b/block/ssh.c
index 12fd4f39e8..ce2363a471 100644
--- a/block/ssh.c
+++ b/block/ssh.c
@@ -24,8 +24,8 @@
#include "qemu/osdep.h"
-#include <libssh2.h>
-#include <libssh2_sftp.h>
+#include <libssh/libssh.h>
+#include <libssh/sftp.h>
#include "block/block_int.h"
#include "block/qdict.h"
@@ -43,14 +43,13 @@
#include "qapi/qobject-output-visitor.h"
#include "trace.h"
-/*
- * TRACE_LIBSSH2=<bitmask> enables tracing in libssh2 itself. Note
- * that this requires that libssh2 was specially compiled with the
- * `./configure --enable-debug' option, so most likely you will have
- * to compile it yourself. The meaning of <bitmask> is described
- * here: http://www.libssh2.org/libssh2_trace.html
+/* TRACE_LIBSSH=<level> enables tracing in libssh itself.
+ * The meaning of <level> is described here:
+ * http://api.libssh.org/master/group__libssh__log.html
*/
-#define TRACE_LIBSSH2 0 /* or try: LIBSSH2_TRACE_SFTP */
+#define TRACE_LIBSSH 0 /* see: SSH_LOG_* */
+
+#define HAVE_LIBSSH_0_8 (LIBSSH_VERSION_INT >= SSH_VERSION_INT(0, 8, 0))
typedef struct BDRVSSHState {
/* Coroutine. */
@@ -58,18 +57,14 @@ typedef struct BDRVSSHState {
/* SSH connection. */
int sock; /* socket */
- LIBSSH2_SESSION *session; /* ssh session */
- LIBSSH2_SFTP *sftp; /* sftp session */
- LIBSSH2_SFTP_HANDLE *sftp_handle; /* sftp remote file handle */
+ ssh_session session; /* ssh session */
+ sftp_session sftp; /* sftp session */
+ sftp_file sftp_handle; /* sftp remote file handle */
- /* See ssh_seek() function below. */
- int64_t offset;
- bool offset_op_read;
-
- /* File attributes at open. We try to keep the .filesize field
+ /* File attributes at open. We try to keep the .size field
* updated if it changes (eg by writing at the end of the file).
*/
- LIBSSH2_SFTP_ATTRIBUTES attrs;
+ sftp_attributes attrs;
InetSocketAddress *inet;
@@ -89,7 +84,6 @@ static void ssh_state_init(BDRVSSHState *s)
{
memset(s, 0, sizeof *s);
s->sock = -1;
- s->offset = -1;
qemu_co_mutex_init(&s->lock);
}
@@ -97,21 +91,20 @@ static void ssh_state_free(BDRVSSHState *s)
{
g_free(s->user);
+ if (s->attrs) {
+ sftp_attributes_free(s->attrs);
+ }
if (s->sftp_handle) {
- libssh2_sftp_close(s->sftp_handle);
+ sftp_close(s->sftp_handle);
}
if (s->sftp) {
- libssh2_sftp_shutdown(s->sftp);
+ sftp_free(s->sftp);
}
if (s->session) {
- libssh2_session_disconnect(s->session,
- "from qemu ssh client: "
- "user closed the connection");
- libssh2_session_free(s->session);
- }
- if (s->sock >= 0) {
- close(s->sock);
+ ssh_disconnect(s->session);
+ ssh_free(s->session);
}
+ /* s->sock is owned by the ssh_session, which frees it. */
}
static void GCC_FMT_ATTR(3, 4)
@@ -125,13 +118,13 @@ session_error_setg(Error **errp, BDRVSSHState *s, const
char *fs, ...)
va_end(args);
if (s->session) {
- char *ssh_err;
+ const char *ssh_err;
int ssh_err_code;
- /* This is not an errno. See <libssh2.h>. */
- ssh_err_code = libssh2_session_last_error(s->session,
- &ssh_err, NULL, 0);
- error_setg(errp, "%s: %s (libssh2 error code: %d)",
+ /* This is not an errno. See <libssh/libssh.h>. */
+ ssh_err = ssh_get_error(s->session);
+ ssh_err_code = ssh_get_error_code(s->session);
+ error_setg(errp, "%s: %s (libssh error code: %d)",
msg, ssh_err, ssh_err_code);
} else {
error_setg(errp, "%s", msg);
@@ -150,18 +143,18 @@ sftp_error_setg(Error **errp, BDRVSSHState *s, const char
*fs, ...)
va_end(args);
if (s->sftp) {
- char *ssh_err;
+ const char *ssh_err;
int ssh_err_code;
- unsigned long sftp_err_code;
+ int sftp_err_code;
- /* This is not an errno. See <libssh2.h>. */
- ssh_err_code = libssh2_session_last_error(s->session,
- &ssh_err, NULL, 0);
- /* See <libssh2_sftp.h>. */
- sftp_err_code = libssh2_sftp_last_error((s)->sftp);
+ /* This is not an errno. See <libssh/libssh.h>. */
+ ssh_err = ssh_get_error(s->session);
+ ssh_err_code = ssh_get_error_code(s->session);
+ /* See <libssh/sftp.h>. */
+ sftp_err_code = sftp_get_error(s->sftp);
error_setg(errp,
- "%s: %s (libssh2 error code: %d, sftp error code: %lu)",
+ "%s: %s (libssh error code: %d, sftp error code: %d)",
msg, ssh_err, ssh_err_code, sftp_err_code);
} else {
error_setg(errp, "%s", msg);
@@ -171,15 +164,15 @@ sftp_error_setg(Error **errp, BDRVSSHState *s, const char
*fs, ...)
static void sftp_error_trace(BDRVSSHState *s, const char *op)
{
- char *ssh_err;
+ const char *ssh_err;
int ssh_err_code;
- unsigned long sftp_err_code;
+ int sftp_err_code;
- /* This is not an errno. See <libssh2.h>. */
- ssh_err_code = libssh2_session_last_error(s->session,
- &ssh_err, NULL, 0);
- /* See <libssh2_sftp.h>. */
- sftp_err_code = libssh2_sftp_last_error((s)->sftp);
+ /* This is not an errno. See <libssh/libssh.h>. */
+ ssh_err = ssh_get_error(s->session);
+ ssh_err_code = ssh_get_error_code(s->session);
+ /* See <libssh/sftp.h>. */
+ sftp_err_code = sftp_get_error(s->sftp);
trace_sftp_error(op, ssh_err, ssh_err_code, sftp_err_code);
}
@@ -280,82 +273,89 @@ static void ssh_parse_filename(const char *filename,
QDict *options,
parse_uri(filename, options, errp);
}
-static int check_host_key_knownhosts(BDRVSSHState *s,
- const char *host, int port, Error **errp)
+static int check_host_key_knownhosts(BDRVSSHState *s, Error **errp)
{
- const char *home;
- char *knh_file = NULL;
- LIBSSH2_KNOWNHOSTS *knh = NULL;
- struct libssh2_knownhost *found;
- int ret, r;
- const char *hostkey;
- size_t len;
- int type;
+ int ret;
+#if HAVE_LIBSSH_0_8
+ enum ssh_known_hosts_e state;
- hostkey = libssh2_session_hostkey(s->session, &len, &type);
- if (!hostkey) {
+ state = ssh_session_is_known_server(s->session);
+ trace_ssh_server_status(state);
+
+ switch (state) {
+ case SSH_KNOWN_HOSTS_OK:
+ /* OK */
+ trace_ssh_check_host_key_knownhosts();
+ break;
+ case SSH_KNOWN_HOSTS_CHANGED:
ret = -EINVAL;
- session_error_setg(errp, s, "failed to read remote host key");
+ error_setg(errp, "host key does not match the one in known_hosts");
goto out;
- }
-
- knh = libssh2_knownhost_init(s->session);
- if (!knh) {
+ case SSH_KNOWN_HOSTS_OTHER:
ret = -EINVAL;
- session_error_setg(errp, s,
- "failed to initialize known hosts support");
+ error_setg(errp,
+ "host key for this server not found, another type exists");
+ goto out;
+ case SSH_KNOWN_HOSTS_UNKNOWN:
+ ret = -ENOENT;
+ error_setg(errp, "no host key was found in known_hosts");
+ goto out;
+ case SSH_KNOWN_HOSTS_NOT_FOUND:
+ ret = -EINVAL;
+ error_setg(errp, "known_hosts file not found");
+ goto out;
+ case SSH_KNOWN_HOSTS_ERROR:
+ ret = -EINVAL;
+ error_setg(errp, "error while checking the host");
+ goto out;
+ default:
+ ret = -EINVAL;
+ error_setg(errp, "error while checking for known server");
goto out;
}
+#else /* !HAVE_LIBSSH_0_8 */
+ int state;
- home = getenv("HOME");
- if (home) {
- knh_file = g_strdup_printf("%s/.ssh/known_hosts", home);
- } else {
- knh_file = g_strdup_printf("/root/.ssh/known_hosts");
- }
-
- /* Read all known hosts from OpenSSH-style known_hosts file. */
- libssh2_knownhost_readfile(knh, knh_file, LIBSSH2_KNOWNHOST_FILE_OPENSSH);
+ state = ssh_is_server_known(s->session);
+ trace_ssh_server_status(state);
- r = libssh2_knownhost_checkp(knh, host, port, hostkey, len,
- LIBSSH2_KNOWNHOST_TYPE_PLAIN|
- LIBSSH2_KNOWNHOST_KEYENC_RAW,
- &found);
- switch (r) {
- case LIBSSH2_KNOWNHOST_CHECK_MATCH:
+ switch (state) {
+ case SSH_SERVER_KNOWN_OK:
/* OK */
- trace_ssh_check_host_key_knownhosts(found->key);
+ trace_ssh_check_host_key_knownhosts();
break;
- case LIBSSH2_KNOWNHOST_CHECK_MISMATCH:
+ case SSH_SERVER_KNOWN_CHANGED:
+ ret = -EINVAL;
+ error_setg(errp, "host key does not match the one in known_hosts");
+ goto out;
+ case SSH_SERVER_FOUND_OTHER:
ret = -EINVAL;
- session_error_setg(errp, s,
- "host key does not match the one in known_hosts"
- " (found key %s)", found->key);
+ error_setg(errp,
+ "host key for this server not found, another type exists");
+ goto out;
+ case SSH_SERVER_FILE_NOT_FOUND:
+ ret = -ENOENT;
+ error_setg(errp, "known_hosts file not found");
goto out;
- case LIBSSH2_KNOWNHOST_CHECK_NOTFOUND:
+ case SSH_SERVER_NOT_KNOWN:
ret = -EINVAL;
- session_error_setg(errp, s, "no host key was found in known_hosts");
+ error_setg(errp, "no host key was found in known_hosts");
goto out;
- case LIBSSH2_KNOWNHOST_CHECK_FAILURE:
+ case SSH_SERVER_ERROR:
ret = -EINVAL;
- session_error_setg(errp, s,
- "failure matching the host key with known_hosts");
+ error_setg(errp, "server error");
goto out;
default:
ret = -EINVAL;
- session_error_setg(errp, s, "unknown error matching the host key"
- " with known_hosts (%d)", r);
+ error_setg(errp, "error while checking for known server");
goto out;
}
+#endif /* !HAVE_LIBSSH_0_8 */
/* known_hosts checking successful. */
ret = 0;
out:
- if (knh != NULL) {
- libssh2_knownhost_free(knh);
- }
- g_free(knh_file);
return ret;
}
@@ -399,18 +399,34 @@ static int compare_fingerprint(const unsigned char
*fingerprint, size_t len,
static int
check_host_key_hash(BDRVSSHState *s, const char *hash,
- int hash_type, size_t fingerprint_len, Error **errp)
+ enum ssh_publickey_hash_type type, Error **errp)
{
- const char *fingerprint;
+ int r;
+ ssh_key pubkey;
+ unsigned char *server_hash;
+ size_t server_hash_len;
- fingerprint = libssh2_hostkey_hash(s->session, hash_type);
- if (!fingerprint) {
+#if HAVE_LIBSSH_0_8
+ r = ssh_get_server_publickey(s->session, &pubkey);
+#else
+ r = ssh_get_publickey(s->session, &pubkey);
+#endif
+ if (r != SSH_OK) {
session_error_setg(errp, s, "failed to read remote host key");
return -EINVAL;
}
- if(compare_fingerprint((unsigned char *) fingerprint, fingerprint_len,
- hash) != 0) {
+ r = ssh_get_publickey_hash(pubkey, type, &server_hash, &server_hash_len);
+ ssh_key_free(pubkey);
+ if (r != 0) {
+ session_error_setg(errp, s,
+ "failed reading the hash of the server SSH key");
+ return -EINVAL;
+ }
+
+ r = compare_fingerprint(server_hash, server_hash_len, hash);
+ ssh_clean_pubkey_hash(&server_hash);
+ if (r != 0) {
error_setg(errp, "remote host key does not match host_key_check '%s'",
hash);
return -EPERM;
@@ -419,8 +435,7 @@ check_host_key_hash(BDRVSSHState *s, const char *hash,
return 0;
}
-static int check_host_key(BDRVSSHState *s, const char *host, int port,
- SshHostKeyCheck *hkc, Error **errp)
+static int check_host_key(BDRVSSHState *s, SshHostKeyCheck *hkc, Error **errp)
{
SshHostKeyCheckMode mode;
@@ -436,15 +451,15 @@ static int check_host_key(BDRVSSHState *s, const char
*host, int port,
case SSH_HOST_KEY_CHECK_MODE_HASH:
if (hkc->u.hash.type == SSH_HOST_KEY_CHECK_HASH_TYPE_MD5) {
return check_host_key_hash(s, hkc->u.hash.hash,
- LIBSSH2_HOSTKEY_HASH_MD5, 16, errp);
+ SSH_PUBLICKEY_HASH_MD5, errp);
} else if (hkc->u.hash.type == SSH_HOST_KEY_CHECK_HASH_TYPE_SHA1) {
return check_host_key_hash(s, hkc->u.hash.hash,
- LIBSSH2_HOSTKEY_HASH_SHA1, 20, errp);
+ SSH_PUBLICKEY_HASH_SHA1, errp);
}
g_assert_not_reached();
break;
case SSH_HOST_KEY_CHECK_MODE_KNOWN_HOSTS:
- return check_host_key_knownhosts(s, host, port, errp);
+ return check_host_key_knownhosts(s, errp);
default:
g_assert_not_reached();
}
@@ -452,60 +467,42 @@ static int check_host_key(BDRVSSHState *s, const char
*host, int port,
return -EINVAL;
}
-static int authenticate(BDRVSSHState *s, const char *user, Error **errp)
+static int authenticate(BDRVSSHState *s, Error **errp)
{
int r, ret;
- const char *userauthlist;
- LIBSSH2_AGENT *agent = NULL;
- struct libssh2_agent_publickey *identity;
- struct libssh2_agent_publickey *prev_identity = NULL;
+ int method;
- userauthlist = libssh2_userauth_list(s->session, user, strlen(user));
- if (strstr(userauthlist, "publickey") == NULL) {
+ /* Try to authenticate with the "none" method. */
+ r = ssh_userauth_none(s->session, NULL);
+ if (r == SSH_AUTH_ERROR) {
ret = -EPERM;
- error_setg(errp,
- "remote server does not support \"publickey\" authentication");
+ session_error_setg(errp, s, "failed to authenticate using none "
+ "authentication");
goto out;
- }
-
- /* Connect to ssh-agent and try each identity in turn. */
- agent = libssh2_agent_init(s->session);
- if (!agent) {
- ret = -EINVAL;
- session_error_setg(errp, s, "failed to initialize ssh-agent support");
- goto out;
- }
- if (libssh2_agent_connect(agent)) {
- ret = -ECONNREFUSED;
- session_error_setg(errp, s, "failed to connect to ssh-agent");
- goto out;
- }
- if (libssh2_agent_list_identities(agent)) {
- ret = -EINVAL;
- session_error_setg(errp, s,
- "failed requesting identities from ssh-agent");
+ } else if (r == SSH_AUTH_SUCCESS) {
+ /* Authenticated! */
+ ret = 0;
goto out;
}
- for(;;) {
- r = libssh2_agent_get_identity(agent, &identity, prev_identity);
- if (r == 1) { /* end of list */
- break;
- }
- if (r < 0) {
+ method = ssh_userauth_list(s->session, NULL);
+ trace_ssh_auth_methods(method);
+
+ /* Try to authenticate with publickey, using the ssh-agent
+ * if available.
+ */
+ if (method & SSH_AUTH_METHOD_PUBLICKEY) {
+ r = ssh_userauth_publickey_auto(s->session, NULL, NULL);
+ if (r == SSH_AUTH_ERROR) {
ret = -EINVAL;
- session_error_setg(errp, s,
- "failed to obtain identity from ssh-agent");
+ session_error_setg(errp, s, "failed to authenticate using "
+ "publickey authentication");
goto out;
- }
- r = libssh2_agent_userauth(agent, user, identity);
- if (r == 0) {
+ } else if (r == SSH_AUTH_SUCCESS) {
/* Authenticated! */
ret = 0;
goto out;
}
- /* Failed to authenticate with this identity, try the next one. */
- prev_identity = identity;
}
ret = -EPERM;
@@ -513,13 +510,6 @@ static int authenticate(BDRVSSHState *s, const char *user,
Error **errp)
"and the identities held by your ssh-agent");
out:
- if (agent != NULL) {
- /* Note: libssh2 implementation implicitly calls
- * libssh2_agent_disconnect if necessary.
- */
- libssh2_agent_free(agent);
- }
-
return ret;
}
@@ -638,7 +628,8 @@ static int connect_to_ssh(BDRVSSHState *s,
BlockdevOptionsSsh *opts,
int ssh_flags, int creat_mode, Error **errp)
{
int r, ret;
- long port = 0;
+ unsigned int port = 0;
+ int new_sock = -1;
if (opts->has_user) {
s->user = g_strdup(opts->user);
@@ -655,71 +646,145 @@ static int connect_to_ssh(BDRVSSHState *s,
BlockdevOptionsSsh *opts,
s->inet = opts->server;
opts->server = NULL;
- if (qemu_strtol(s->inet->port, NULL, 10, &port) < 0) {
+ if (qemu_strtoui(s->inet->port, NULL, 10, &port) < 0) {
error_setg(errp, "Use only numeric port value");
ret = -EINVAL;
goto err;
}
/* Open the socket and connect. */
- s->sock = inet_connect_saddr(s->inet, errp);
- if (s->sock < 0) {
+ new_sock = inet_connect_saddr(s->inet, errp);
+ if (new_sock < 0) {
ret = -EIO;
goto err;
}
+ /* Try to disable the Nagle algorithm on TCP sockets to reduce latency,
+ * but do not fail if it cannot be disabled.
+ */
+ r = socket_set_nodelay(new_sock);
+ if (r < 0) {
+ warn_report("setting NODELAY for the ssh server %s failed: %m",
+ s->inet->host);
+ }
+
/* Create SSH session. */
- s->session = libssh2_session_init();
+ s->session = ssh_new();
if (!s->session) {
ret = -EINVAL;
- session_error_setg(errp, s, "failed to initialize libssh2 session");
+ session_error_setg(errp, s, "failed to initialize libssh session");
goto err;
}
-#if TRACE_LIBSSH2 != 0
- libssh2_trace(s->session, TRACE_LIBSSH2);
-#endif
+ /* Make sure we are in blocking mode during the connection and
+ * authentication phases.
+ */
+ ssh_set_blocking(s->session, 1);
- r = libssh2_session_handshake(s->session, s->sock);
- if (r != 0) {
+ r = ssh_options_set(s->session, SSH_OPTIONS_USER, s->user);
+ if (r < 0) {
+ ret = -EINVAL;
+ session_error_setg(errp, s,
+ "failed to set the user in the libssh session");
+ goto err;
+ }
+
+ r = ssh_options_set(s->session, SSH_OPTIONS_HOST, s->inet->host);
+ if (r < 0) {
+ ret = -EINVAL;
+ session_error_setg(errp, s,
+ "failed to set the host in the libssh session");
+ goto err;
+ }
+
+ if (port > 0) {
+ r = ssh_options_set(s->session, SSH_OPTIONS_PORT, &port);
+ if (r < 0) {
+ ret = -EINVAL;
+ session_error_setg(errp, s,
+ "failed to set the port in the libssh session");
+ goto err;
+ }
+ }
+
+ r = ssh_options_set(s->session, SSH_OPTIONS_COMPRESSION, "none");
+ if (r < 0) {
+ ret = -EINVAL;
+ session_error_setg(errp, s,
+ "failed to disable the compression in the libssh "
+ "session");
+ goto err;
+ }
+
+ /* Read ~/.ssh/config. */
+ r = ssh_options_parse_config(s->session, NULL);
+ if (r < 0) {
+ ret = -EINVAL;
+ session_error_setg(errp, s, "failed to parse ~/.ssh/config");
+ goto err;
+ }
+
+ r = ssh_options_set(s->session, SSH_OPTIONS_FD, &new_sock);
+ if (r < 0) {
+ ret = -EINVAL;
+ session_error_setg(errp, s,
+ "failed to set the socket in the libssh session");
+ goto err;
+ }
+ /* libssh took ownership of the socket. */
+ s->sock = new_sock;
+ new_sock = -1;
+
+ /* Connect. */
+ r = ssh_connect(s->session);
+ if (r != SSH_OK) {
ret = -EINVAL;
session_error_setg(errp, s, "failed to establish SSH session");
goto err;
}
/* Check the remote host's key against known_hosts. */
- ret = check_host_key(s, s->inet->host, port, opts->host_key_check, errp);
+ ret = check_host_key(s, opts->host_key_check, errp);
if (ret < 0) {
goto err;
}
/* Authenticate. */
- ret = authenticate(s, s->user, errp);
+ ret = authenticate(s, errp);
if (ret < 0) {
goto err;
}
/* Start SFTP. */
- s->sftp = libssh2_sftp_init(s->session);
+ s->sftp = sftp_new(s->session);
if (!s->sftp) {
- session_error_setg(errp, s, "failed to initialize sftp handle");
+ session_error_setg(errp, s, "failed to create sftp handle");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ r = sftp_init(s->sftp);
+ if (r < 0) {
+ sftp_error_setg(errp, s, "failed to initialize sftp handle");
ret = -EINVAL;
goto err;
}
/* Open the remote file. */
trace_ssh_connect_to_ssh(opts->path, ssh_flags, creat_mode);
- s->sftp_handle = libssh2_sftp_open(s->sftp, opts->path, ssh_flags,
- creat_mode);
+ s->sftp_handle = sftp_open(s->sftp, opts->path, ssh_flags, creat_mode);
if (!s->sftp_handle) {
- session_error_setg(errp, s, "failed to open remote file '%s'",
- opts->path);
+ sftp_error_setg(errp, s, "failed to open remote file '%s'",
+ opts->path);
ret = -EINVAL;
goto err;
}
- r = libssh2_sftp_fstat(s->sftp_handle, &s->attrs);
- if (r < 0) {
+ /* Make sure the SFTP file is handled in blocking mode. */
+ sftp_file_set_blocking(s->sftp_handle);
+
+ s->attrs = sftp_fstat(s->sftp_handle);
+ if (!s->attrs) {
sftp_error_setg(errp, s, "failed to read file attributes");
return -EINVAL;
}
@@ -727,21 +792,26 @@ static int connect_to_ssh(BDRVSSHState *s,
BlockdevOptionsSsh *opts,
return 0;
err:
+ if (s->attrs) {
+ sftp_attributes_free(s->attrs);
+ }
+ s->attrs = NULL;
if (s->sftp_handle) {
- libssh2_sftp_close(s->sftp_handle);
+ sftp_close(s->sftp_handle);
}
s->sftp_handle = NULL;
if (s->sftp) {
- libssh2_sftp_shutdown(s->sftp);
+ sftp_free(s->sftp);
}
s->sftp = NULL;
if (s->session) {
- libssh2_session_disconnect(s->session,
- "from qemu ssh client: "
- "error opening connection");
- libssh2_session_free(s->session);
+ ssh_disconnect(s->session);
+ ssh_free(s->session);
}
s->session = NULL;
+ if (new_sock >= 0) {
+ close(new_sock);
+ }
return ret;
}
@@ -756,9 +826,11 @@ static int ssh_file_open(BlockDriverState *bs, QDict
*options, int bdrv_flags,
ssh_state_init(s);
- ssh_flags = LIBSSH2_FXF_READ;
+ ssh_flags = 0;
if (bdrv_flags & BDRV_O_RDWR) {
- ssh_flags |= LIBSSH2_FXF_WRITE;
+ ssh_flags |= O_RDWR;
+ } else {
+ ssh_flags |= O_RDONLY;
}
opts = ssh_parse_options(options, errp);
@@ -773,16 +845,13 @@ static int ssh_file_open(BlockDriverState *bs, QDict
*options, int bdrv_flags,
}
/* Go non-blocking. */
- libssh2_session_set_blocking(s->session, 0);
+ ssh_set_blocking(s->session, 0);
qapi_free_BlockdevOptionsSsh(opts);
return 0;
err:
- if (s->sock >= 0) {
- close(s->sock);
- }
s->sock = -1;
qapi_free_BlockdevOptionsSsh(opts);
@@ -795,25 +864,25 @@ static int ssh_grow_file(BDRVSSHState *s, int64_t offset,
Error **errp)
{
ssize_t ret;
char c[1] = { '\0' };
- int was_blocking = libssh2_session_get_blocking(s->session);
+ int was_blocking = ssh_is_blocking(s->session);
/* offset must be strictly greater than the current size so we do
* not overwrite anything */
- assert(offset > 0 && offset > s->attrs.filesize);
+ assert(offset > 0 && offset > s->attrs->size);
- libssh2_session_set_blocking(s->session, 1);
+ ssh_set_blocking(s->session, 1);
- libssh2_sftp_seek64(s->sftp_handle, offset - 1);
- ret = libssh2_sftp_write(s->sftp_handle, c, 1);
+ sftp_seek64(s->sftp_handle, offset - 1);
+ ret = sftp_write(s->sftp_handle, c, 1);
- libssh2_session_set_blocking(s->session, was_blocking);
+ ssh_set_blocking(s->session, was_blocking);
if (ret < 0) {
sftp_error_setg(errp, s, "Failed to grow file");
return -EIO;
}
- s->attrs.filesize = offset;
+ s->attrs->size = offset;
return 0;
}
@@ -841,8 +910,7 @@ static int ssh_co_create(BlockdevCreateOptions *options,
Error **errp)
ssh_state_init(&s);
ret = connect_to_ssh(&s, opts->location,
- LIBSSH2_FXF_READ|LIBSSH2_FXF_WRITE|
- LIBSSH2_FXF_CREAT|LIBSSH2_FXF_TRUNC,
+ O_RDWR | O_CREAT | O_TRUNC,
0644, errp);
if (ret < 0) {
goto fail;
@@ -911,10 +979,8 @@ static int ssh_has_zero_init(BlockDriverState *bs)
/* Assume false, unless we can positively prove it's true. */
int has_zero_init = 0;
- if (s->attrs.flags & LIBSSH2_SFTP_ATTR_PERMISSIONS) {
- if (s->attrs.permissions & LIBSSH2_SFTP_S_IFREG) {
- has_zero_init = 1;
- }
+ if (s->attrs->type == SSH_FILEXFER_TYPE_REGULAR) {
+ has_zero_init = 1;
}
return has_zero_init;
@@ -951,12 +1017,12 @@ static coroutine_fn void co_yield(BDRVSSHState *s,
BlockDriverState *bs)
.co = qemu_coroutine_self()
};
- r = libssh2_session_block_directions(s->session);
+ r = ssh_get_poll_flags(s->session);
- if (r & LIBSSH2_SESSION_BLOCK_INBOUND) {
+ if (r & SSH_READ_PENDING) {
rd_handler = restart_coroutine;
}
- if (r & LIBSSH2_SESSION_BLOCK_OUTBOUND) {
+ if (r & SSH_WRITE_PENDING) {
wr_handler = restart_coroutine;
}
@@ -968,33 +1034,6 @@ static coroutine_fn void co_yield(BDRVSSHState *s,
BlockDriverState *bs)
trace_ssh_co_yield_back(s->sock);
}
-/* SFTP has a function `libssh2_sftp_seek64' which seeks to a position
- * in the remote file. Notice that it just updates a field in the
- * sftp_handle structure, so there is no network traffic and it cannot
- * fail.
- *
- * However, `libssh2_sftp_seek64' does have a catastrophic effect on
- * performance since it causes the handle to throw away all in-flight
- * reads and buffered readahead data. Therefore this function tries
- * to be intelligent about when to call the underlying libssh2 function.
- */
-#define SSH_SEEK_WRITE 0
-#define SSH_SEEK_READ 1
-#define SSH_SEEK_FORCE 2
-
-static void ssh_seek(BDRVSSHState *s, int64_t offset, int flags)
-{
- bool op_read = (flags & SSH_SEEK_READ) != 0;
- bool force = (flags & SSH_SEEK_FORCE) != 0;
-
- if (force || op_read != s->offset_op_read || offset != s->offset) {
- trace_ssh_seek(offset);
- libssh2_sftp_seek64(s->sftp_handle, offset);
- s->offset = offset;
- s->offset_op_read = op_read;
- }
-}
-
static coroutine_fn int ssh_read(BDRVSSHState *s, BlockDriverState *bs,
int64_t offset, size_t size,
QEMUIOVector *qiov)
@@ -1006,7 +1045,8 @@ static coroutine_fn int ssh_read(BDRVSSHState *s,
BlockDriverState *bs,
trace_ssh_read(offset, size);
- ssh_seek(s, offset, SSH_SEEK_READ);
+ trace_ssh_seek(offset);
+ sftp_seek64(s->sftp_handle, offset);
/* This keeps track of the current iovec element ('i'), where we
* will write to next ('buf'), and the end of the current iovec
@@ -1016,35 +1056,33 @@ static coroutine_fn int ssh_read(BDRVSSHState *s,
BlockDriverState *bs,
buf = i->iov_base;
end_of_vec = i->iov_base + i->iov_len;
- /* libssh2 has a hard-coded limit of 2000 bytes per request,
- * although it will also do readahead behind our backs. Therefore
- * we may have to do repeated reads here until we have read 'size'
- * bytes.
- */
for (got = 0; got < size; ) {
again:
- trace_ssh_read_buf(buf, end_of_vec - buf);
- r = libssh2_sftp_read(s->sftp_handle, buf, end_of_vec - buf);
- trace_ssh_read_return(r);
+ trace_ssh_read_buf(buf, end_of_vec - buf, MIN(end_of_vec - buf,
16384));
+ /* The size of SFTP packets is limited to 32K bytes, so limit
+ * the amount of data requested to 16K, as libssh currently
+ * does not handle multiple requests on its own:
+ * https://red.libssh.org/issues/58
+ */
+ r = sftp_read(s->sftp_handle, buf, MIN(end_of_vec - buf, 16384));
+ trace_ssh_read_return(r, sftp_get_error(s->sftp));
- if (r == LIBSSH2_ERROR_EAGAIN || r == LIBSSH2_ERROR_TIMEOUT) {
+ if (r == SSH_AGAIN) {
co_yield(s, bs);
goto again;
}
- if (r < 0) {
- sftp_error_trace(s, "read");
- s->offset = -1;
- return -EIO;
- }
- if (r == 0) {
+ if (r == SSH_EOF || (r == 0 && sftp_get_error(s->sftp) == SSH_FX_EOF))
{
/* EOF: Short read so pad the buffer with zeroes and return it. */
qemu_iovec_memset(qiov, got, 0, size - got);
return 0;
}
+ if (r <= 0) {
+ sftp_error_trace(s, "read");
+ return -EIO;
+ }
got += r;
buf += r;
- s->offset += r;
if (buf >= end_of_vec && got < size) {
i++;
buf = i->iov_base;
@@ -1081,7 +1119,8 @@ static int ssh_write(BDRVSSHState *s, BlockDriverState
*bs,
trace_ssh_write(offset, size);
- ssh_seek(s, offset, SSH_SEEK_WRITE);
+ trace_ssh_seek(offset);
+ sftp_seek64(s->sftp_handle, offset);
/* This keeps track of the current iovec element ('i'), where we
* will read from next ('buf'), and the end of the current iovec
@@ -1093,45 +1132,34 @@ static int ssh_write(BDRVSSHState *s, BlockDriverState
*bs,
for (written = 0; written < size; ) {
again:
- trace_ssh_write_buf(buf, end_of_vec - buf);
- r = libssh2_sftp_write(s->sftp_handle, buf, end_of_vec - buf);
- trace_ssh_write_return(r);
+ trace_ssh_write_buf(buf, end_of_vec - buf, MIN(end_of_vec - buf,
131072));
+ /* Avoid too large data packets, as libssh currently does not
+ * handle multiple requests on its own:
+ * https://red.libssh.org/issues/58
+ */
+ r = sftp_write(s->sftp_handle, buf, MIN(end_of_vec - buf, 131072));
+ trace_ssh_write_return(r, sftp_get_error(s->sftp));
- if (r == LIBSSH2_ERROR_EAGAIN || r == LIBSSH2_ERROR_TIMEOUT) {
+ if (r == SSH_AGAIN) {
co_yield(s, bs);
goto again;
}
if (r < 0) {
sftp_error_trace(s, "write");
- s->offset = -1;
return -EIO;
}
- /* The libssh2 API is very unclear about this. A comment in
- * the code says "nothing was acked, and no EAGAIN was
- * received!" which apparently means that no data got sent
- * out, and the underlying channel didn't return any EAGAIN
- * indication. I think this is a bug in either libssh2 or
- * OpenSSH (server-side). In any case, forcing a seek (to
- * discard libssh2 internal buffers), and then trying again
- * works for me.
- */
- if (r == 0) {
- ssh_seek(s, offset + written, SSH_SEEK_WRITE|SSH_SEEK_FORCE);
- co_yield(s, bs);
- goto again;
- }
written += r;
buf += r;
- s->offset += r;
if (buf >= end_of_vec && written < size) {
i++;
buf = i->iov_base;
end_of_vec = i->iov_base + i->iov_len;
}
- if (offset + written > s->attrs.filesize)
- s->attrs.filesize = offset + written;
+ if (offset + written > s->attrs->size) {
+ s->attrs->size = offset + written;
+ }
}
return 0;
@@ -1166,24 +1194,24 @@ static void unsafe_flush_warning(BDRVSSHState *s, const
char *what)
}
}
-#ifdef HAS_LIBSSH2_SFTP_FSYNC
+#if HAVE_LIBSSH_0_8
static coroutine_fn int ssh_flush(BDRVSSHState *s, BlockDriverState *bs)
{
int r;
trace_ssh_flush();
+
+ if (!sftp_extension_supported(s->sftp, "address@hidden", "1")) {
+ unsafe_flush_warning(s, "OpenSSH >= 6.3");
+ return 0;
+ }
again:
- r = libssh2_sftp_fsync(s->sftp_handle);
- if (r == LIBSSH2_ERROR_EAGAIN || r == LIBSSH2_ERROR_TIMEOUT) {
+ r = sftp_fsync(s->sftp_handle);
+ if (r == SSH_AGAIN) {
co_yield(s, bs);
goto again;
}
- if (r == LIBSSH2_ERROR_SFTP_PROTOCOL &&
- libssh2_sftp_last_error(s->sftp) == LIBSSH2_FX_OP_UNSUPPORTED) {
- unsafe_flush_warning(s, "OpenSSH >= 6.3");
- return 0;
- }
if (r < 0) {
sftp_error_trace(s, "fsync");
return -EIO;
@@ -1204,25 +1232,25 @@ static coroutine_fn int ssh_co_flush(BlockDriverState
*bs)
return ret;
}
-#else /* !HAS_LIBSSH2_SFTP_FSYNC */
+#else /* !HAVE_LIBSSH_0_8 */
static coroutine_fn int ssh_co_flush(BlockDriverState *bs)
{
BDRVSSHState *s = bs->opaque;
- unsafe_flush_warning(s, "libssh2 >= 1.4.4");
+ unsafe_flush_warning(s, "libssh >= 0.8.0");
return 0;
}
-#endif /* !HAS_LIBSSH2_SFTP_FSYNC */
+#endif /* !HAVE_LIBSSH_0_8 */
static int64_t ssh_getlength(BlockDriverState *bs)
{
BDRVSSHState *s = bs->opaque;
int64_t length;
- /* Note we cannot make a libssh2 call here. */
- length = (int64_t) s->attrs.filesize;
+ /* Note we cannot make a libssh call here. */
+ length = (int64_t) s->attrs->size;
trace_ssh_getlength(length);
return length;
@@ -1239,12 +1267,12 @@ static int coroutine_fn
ssh_co_truncate(BlockDriverState *bs, int64_t offset,
return -ENOTSUP;
}
- if (offset < s->attrs.filesize) {
+ if (offset < s->attrs->size) {
error_setg(errp, "ssh driver does not support shrinking files");
return -ENOTSUP;
}
- if (offset == s->attrs.filesize) {
+ if (offset == s->attrs->size) {
return 0;
}
@@ -1339,12 +1367,16 @@ static void bdrv_ssh_init(void)
{
int r;
- r = libssh2_init(0);
+ r = ssh_init();
if (r != 0) {
- fprintf(stderr, "libssh2 initialization failed, %d\n", r);
+ fprintf(stderr, "libssh initialization failed, %d\n", r);
exit(EXIT_FAILURE);
}
+#if TRACE_LIBSSH != 0
+ ssh_set_log_level(TRACE_LIBSSH);
+#endif
+
bdrv_register(&bdrv_ssh);
}
diff --git a/block/trace-events b/block/trace-events
index eab51497fc..0d2126e840 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -169,19 +169,21 @@ nbd_co_request_fail(uint64_t from, uint32_t len, uint64_t
handle, uint16_t flags
# ssh.c
ssh_restart_coroutine(void *co) "co=%p"
ssh_flush(void) "fsync"
-ssh_check_host_key_knownhosts(const char *key) "host key OK: %s"
+ssh_check_host_key_knownhosts(void) "host key OK"
ssh_connect_to_ssh(char *path, int flags, int mode) "opening file %s
flags=0x%x creat_mode=0%o"
ssh_co_yield(int sock, void *rd_handler, void *wr_handler) "s->sock=%d
rd_handler=%p wr_handler=%p"
ssh_co_yield_back(int sock) "s->sock=%d - back"
ssh_getlength(int64_t length) "length=%" PRIi64
ssh_co_create_opts(uint64_t size) "total_size=%" PRIu64
ssh_read(int64_t offset, size_t size) "offset=%" PRIi64 " size=%zu"
-ssh_read_buf(void *buf, size_t size) "sftp_read buf=%p size=%zu"
-ssh_read_return(ssize_t ret) "sftp_read returned %zd"
+ssh_read_buf(void *buf, size_t size, size_t actual_size) "sftp_read buf=%p
size=%zu (actual size=%zu)"
+ssh_read_return(ssize_t ret, int sftp_err) "sftp_read returned %zd (sftp
error=%d)"
ssh_write(int64_t offset, size_t size) "offset=%" PRIi64 " size=%zu"
-ssh_write_buf(void *buf, size_t size) "sftp_write buf=%p size=%zu"
-ssh_write_return(ssize_t ret) "sftp_write returned %zd"
+ssh_write_buf(void *buf, size_t size, size_t actual_size) "sftp_write buf=%p
size=%zu (actual size=%zu)"
+ssh_write_return(ssize_t ret, int sftp_err) "sftp_write returned %zd (sftp
error=%d)"
ssh_seek(int64_t offset) "seeking to offset=%" PRIi64
+ssh_auth_methods(int methods) "auth methods=%x"
+ssh_server_status(int status) "server status=%d"
# curl.c
curl_timer_cb(long timeout_ms) "timer callback timeout_ms %ld"
@@ -214,4 +216,4 @@ sheepdog_snapshot_create(const char *sn_name, const char
*id) "%s %s"
sheepdog_snapshot_create_inode(const char *name, uint32_t snap, uint32_t vdi)
"s->inode: name %s snap_id 0x%" PRIx32 " vdi 0x%" PRIx32
# ssh.c
-sftp_error(const char *op, const char *ssh_err, int ssh_err_code, unsigned
long sftp_err_code) "%s failed: %s (libssh2 error code: %d, sftp error code:
%lu)"
+sftp_error(const char *op, const char *ssh_err, int ssh_err_code, int
sftp_err_code) "%s failed: %s (libssh error code: %d, sftp error code: %d)"
diff --git a/configure b/configure
index b091b82cb3..bfdd70c40a 100755
--- a/configure
+++ b/configure
@@ -472,7 +472,7 @@ auth_pam=""
vte=""
virglrenderer=""
tpm=""
-libssh2=""
+libssh=""
live_block_migration="yes"
numa=""
tcmalloc="no"
@@ -1439,9 +1439,9 @@ for opt do
;;
--enable-tpm) tpm="yes"
;;
- --disable-libssh2) libssh2="no"
+ --disable-libssh) libssh="no"
;;
- --enable-libssh2) libssh2="yes"
+ --enable-libssh) libssh="yes"
;;
--disable-live-block-migration) live_block_migration="no"
;;
@@ -1810,7 +1810,7 @@ disabled with --disable-FEATURE, default is enabled if
available:
coroutine-pool coroutine freelist (better performance)
glusterfs GlusterFS backend
tpm TPM support
- libssh2 ssh block device support
+ libssh ssh block device support
numa libnuma support
libxml2 for Parallels image format
tcmalloc tcmalloc support
@@ -3914,43 +3914,17 @@ EOF
fi
##########################################
-# libssh2 probe
-min_libssh2_version=1.2.8
-if test "$libssh2" != "no" ; then
- if $pkg_config --atleast-version=$min_libssh2_version libssh2; then
- libssh2_cflags=$($pkg_config libssh2 --cflags)
- libssh2_libs=$($pkg_config libssh2 --libs)
- libssh2=yes
+# libssh probe
+if test "$libssh" != "no" ; then
+ if $pkg_config --exists libssh; then
+ libssh_cflags=$($pkg_config libssh --cflags)
+ libssh_libs=$($pkg_config libssh --libs)
+ libssh=yes
else
- if test "$libssh2" = "yes" ; then
- error_exit "libssh2 >= $min_libssh2_version required for
--enable-libssh2"
+ if test "$libssh" = "yes" ; then
+ error_exit "libssh required for --enable-libssh"
fi
- libssh2=no
- fi
-fi
-
-##########################################
-# libssh2_sftp_fsync probe
-
-if test "$libssh2" = "yes"; then
- cat > $TMPC <<EOF
-#include <stdio.h>
-#include <libssh2.h>
-#include <libssh2_sftp.h>
-int main(void) {
- LIBSSH2_SESSION *session;
- LIBSSH2_SFTP *sftp;
- LIBSSH2_SFTP_HANDLE *sftp_handle;
- session = libssh2_session_init ();
- sftp = libssh2_sftp_init (session);
- sftp_handle = libssh2_sftp_open (sftp, "/", 0, 0);
- libssh2_sftp_fsync (sftp_handle);
- return 0;
-}
-EOF
- # libssh2_cflags/libssh2_libs defined in previous test.
- if compile_prog "$libssh2_cflags" "$libssh2_libs" ; then
- QEMU_CFLAGS="-DHAS_LIBSSH2_SFTP_FSYNC $QEMU_CFLAGS"
+ libssh=no
fi
fi
@@ -6451,7 +6425,7 @@ echo "GlusterFS support $glusterfs"
echo "gcov $gcov_tool"
echo "gcov enabled $gcov"
echo "TPM support $tpm"
-echo "libssh2 support $libssh2"
+echo "libssh support $libssh"
echo "QOM debugging $qom_cast_debug"
echo "Live block migration $live_block_migration"
echo "lzo support $lzo"
@@ -7144,10 +7118,10 @@ if test "$glusterfs_iocb_has_stat" = "yes" ; then
echo "CONFIG_GLUSTERFS_IOCB_HAS_STAT=y" >> $config_host_mak
fi
-if test "$libssh2" = "yes" ; then
- echo "CONFIG_LIBSSH2=m" >> $config_host_mak
- echo "LIBSSH2_CFLAGS=$libssh2_cflags" >> $config_host_mak
- echo "LIBSSH2_LIBS=$libssh2_libs" >> $config_host_mak
+if test "$libssh" = "yes" ; then
+ echo "CONFIG_LIBSSH=m" >> $config_host_mak
+ echo "LIBSSH_CFLAGS=$libssh_cflags" >> $config_host_mak
+ echo "LIBSSH_LIBS=$libssh_libs" >> $config_host_mak
fi
if test "$live_block_migration" = "yes" ; then
diff --git a/tests/qemu-iotests/207.out b/tests/qemu-iotests/207.out
index ec9823793a..1239d9d648 100644
--- a/tests/qemu-iotests/207.out
+++ b/tests/qemu-iotests/207.out
@@ -68,7 +68,7 @@ virtual size: 4 MiB (4194304 bytes)
{"execute": "blockdev-create", "arguments": {"job-id": "job0", "options":
{"driver": "ssh", "location": {"host-key-check": {"mode": "none"}, "path":
"/this/is/not/an/existing/path", "server": {"host": "127.0.0.1", "port":
"22"}}, "size": 4194304}}}
{"return": {}}
-Job failed: failed to open remote file '/this/is/not/an/existing/path': Failed
opening remote file (libssh2 error code: -31)
+Job failed: failed to open remote file '/this/is/not/an/existing/path': SFTP
server: No such file (libssh error code: 1, sftp error code: 2)
{"execute": "job-dismiss", "arguments": {"id": "job0"}}
{"return": {}}
--
2.21.0
- [Qemu-block] [PATCH v6] ssh: switch from libssh2 to libssh,
Pino Toscano <=
Re: [Qemu-block] [PATCH v6] ssh: switch from libssh2 to libssh, Philippe Mathieu-Daudé, 2019/06/12