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libnbd/SOURCES/0001-generator-Print-full-e...

192 lines
6.8 KiB

From 89f0e33f355681b7c5b1835a09c5fac93c08e71e Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Tue, 23 Jul 2024 17:22:12 +0100
Subject: [PATCH] generator: Print full error in handle_reply_error
Print the full error from the server during handshaking. This
modifies the contract of handle_reply_error so it calls set_error,
which can be overridden by callers or ignored completely.
(cherry picked from commit cf49a49adc8abc8c917437db7461ed9956583877)
---
generator/states-newstyle-opt-go.c | 32 +--------
generator/states-newstyle-opt-list.c | 5 +-
generator/states-newstyle-opt-meta-context.c | 8 +--
generator/states-newstyle.c | 68 ++++++++++++++++++--
4 files changed, 69 insertions(+), 44 deletions(-)
diff --git a/generator/states-newstyle-opt-go.c b/generator/states-newstyle-opt-go.c
index 5bc9a9ae..f6eb8afc 100644
--- a/generator/states-newstyle-opt-go.c
+++ b/generator/states-newstyle-opt-go.c
@@ -247,37 +247,9 @@ STATE_MACHINE {
SET_NEXT_STATE (%.DEAD);
return 0;
}
- /* Decode expected known errors into a nicer string */
- switch (reply) {
- case NBD_REP_ERR_UNSUP:
+ if (reply == NBD_REP_ERR_UNSUP)
assert (h->opt_current == NBD_OPT_INFO);
- set_error (ENOTSUP, "handshake: server lacks NBD_OPT_INFO support");
- break;
- case NBD_REP_ERR_POLICY:
- case NBD_REP_ERR_PLATFORM:
- set_error (0, "handshake: server policy prevents NBD_OPT_GO");
- break;
- case NBD_REP_ERR_INVALID:
- case NBD_REP_ERR_TOO_BIG:
- set_error (EINVAL, "handshake: server rejected NBD_OPT_GO as invalid");
- break;
- case NBD_REP_ERR_TLS_REQD:
- set_error (ENOTSUP, "handshake: server requires TLS encryption first");
- break;
- case NBD_REP_ERR_UNKNOWN:
- set_error (ENOENT, "handshake: server has no export named '%s'",
- h->export_name);
- break;
- case NBD_REP_ERR_SHUTDOWN:
- set_error (ESHUTDOWN, "handshake: server is shutting down");
- break;
- case NBD_REP_ERR_BLOCK_SIZE_REQD:
- set_error (EINVAL, "handshake: server requires specific block sizes");
- break;
- default:
- set_error (0, "handshake: unknown reply from NBD_OPT_GO: 0x%" PRIx32,
- reply);
- }
+
nbd_internal_reset_size_and_flags (h);
h->meta_valid = false;
err = nbd_get_errno () ? : ENOTSUP;
diff --git a/generator/states-newstyle-opt-list.c b/generator/states-newstyle-opt-list.c
index cdd4676e..6605ee0a 100644
--- a/generator/states-newstyle-opt-list.c
+++ b/generator/states-newstyle-opt-list.c
@@ -127,9 +127,8 @@ STATE_MACHINE {
SET_NEXT_STATE (%.DEAD);
return 0;
}
- err = ENOTSUP;
- set_error (err, "unexpected response, possibly the server does not "
- "support listing exports");
+ debug (h, "unexpected response, possibly the server does not "
+ "support listing exports");
break;
}
diff --git a/generator/states-newstyle-opt-meta-context.c b/generator/states-newstyle-opt-meta-context.c
index 6f016e66..3945411e 100644
--- a/generator/states-newstyle-opt-meta-context.c
+++ b/generator/states-newstyle-opt-meta-context.c
@@ -270,12 +270,8 @@ STATE_MACHINE {
}
if (opt == h->opt_current) {
- /* XXX Should we decode specific expected errors, like
- * REP_ERR_UNKNOWN to ENOENT or REP_ERR_TOO_BIG to ERANGE?
- */
- err = ENOTSUP;
- set_error (err, "unexpected response, possibly the server does not "
- "support meta contexts");
+ debug (h, "unexpected response, possibly the server does not "
+ "support meta contexts");
CALL_CALLBACK (h->opt_cb.completion, &err);
nbd_internal_free_option (h);
SET_NEXT_STATE (%.NEGOTIATING);
diff --git a/generator/states-newstyle.c b/generator/states-newstyle.c
index 45893a8b..6c7cc45c 100644
--- a/generator/states-newstyle.c
+++ b/generator/states-newstyle.c
@@ -79,14 +79,18 @@ prepare_for_reply_payload (struct nbd_handle *h, uint32_t opt)
return 0;
}
-/* Check an unexpected server reply. If it is an error, log any
- * message from the server and return 0; otherwise, return -1.
+/* Check an unexpected server reply error.
+ *
+ * This calls set_error with a descriptive error message and returns
+ * 0. Unless there is a further unexpected error while processing
+ * this error, in which case it calls set_error and returns -1.
*/
static int
handle_reply_error (struct nbd_handle *h)
{
uint32_t len;
uint32_t reply;
+ char *msg = NULL;
len = be32toh (h->sbuf.or.option_reply.replylen);
reply = be32toh (h->sbuf.or.option_reply.reply);
@@ -101,9 +105,63 @@ handle_reply_error (struct nbd_handle *h)
return -1;
}
- if (len > 0)
- debug (h, "handshake: server error message: %.*s", (int)len,
- h->sbuf.or.payload.err_msg);
+ /* Decode expected errors into a nicer string.
+ *
+ * XXX Note this string comes directly from the server, and most
+ * libnbd users simply print the error using 'fprintf'. We really
+ * ought to quote this string somehow, but we don't have a useful
+ * function for that.
+ */
+ if (len > 0) {
+ if (asprintf (&msg, ": %.*s",
+ (int)len, h->sbuf.or.payload.err_msg) == -1) {
+ set_error (errno, "asprintf");
+ return -1;
+ }
+ }
+
+ switch (reply) {
+ case NBD_REP_ERR_UNSUP:
+ set_error (ENOTSUP, "the operation is not supported by the server%s",
+ msg ? : "");
+ break;
+ case NBD_REP_ERR_POLICY:
+ set_error (0, "server policy prevents the operation%s",
+ msg ? : "");
+ break;
+ case NBD_REP_ERR_PLATFORM:
+ set_error (0, "the operation is not supported by the server platform%s",
+ msg ? : "");
+ break;
+ case NBD_REP_ERR_INVALID:
+ set_error (EINVAL, "the server rejected this operation as invalid%s",
+ msg ? : "");
+ break;
+ case NBD_REP_ERR_TOO_BIG:
+ set_error (EINVAL, "the operation is too large to process%s",
+ msg ? : "");
+ break;
+ case NBD_REP_ERR_TLS_REQD:
+ set_error (ENOTSUP, "the server requires TLS encryption first%s",
+ msg ? : "");
+ break;
+ case NBD_REP_ERR_UNKNOWN:
+ set_error (ENOENT, "the server has no export named '%s'%s",
+ h->export_name, msg ? : "");
+ break;
+ case NBD_REP_ERR_SHUTDOWN:
+ set_error (ESHUTDOWN, "the server is shutting down%s",
+ msg ? : "");
+ break;
+ case NBD_REP_ERR_BLOCK_SIZE_REQD:
+ set_error (EINVAL, "the server requires specific block sizes%s",
+ msg ? : "");
+ break;
+ default:
+ set_error (0, "handshake: unknown reply from the server: 0x%" PRIx32 "%s",
+ reply, msg ? : "");
+ }
+ free (msg);
return 0;
}
--
2.43.0