[PATCHv3] debuginfod: Check result of calling MHD_add_response_header.
Mark Wielaard
mark@klomp.org
Wed Dec 8 15:16:44 GMT 2021
Although unlikely the MHD_add_response_header can fail for
various reasons. If it fails something odd is going on.
So check we can actually add a response header and log an
error if we cannot.
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
debuginfod/ChangeLog | 12 ++++++++
debuginfod/debuginfod.cxx | 64 +++++++++++++++++++++++++++------------
2 files changed, 56 insertions(+), 20 deletions(-)
v3: Use a wrapper function, if there is an error, always log it
diff --git a/debuginfod/ChangeLog b/debuginfod/ChangeLog
index 8c937d66..8b5df4e1 100644
--- a/debuginfod/ChangeLog
+++ b/debuginfod/ChangeLog
@@ -1,3 +1,15 @@
+2021-12-08 Mark Wielaard <mark@klomp.org>
+
+ * debuginfod.cxx (add_mhd_response_header): New function.
+ (reportable_exception::mhd_send_response): Call
+ MHD_add_response_header.
+ (add_mhd_last_modified): Likewise.
+ (handle_buildid_f_match): Likewise.
+ (handle_buildid_r_match): Likewise.
+ (handle_metrics): Likewise. And check MHD_Response was actually
+ created.
+ (handle_root): Likewise.
+
2021-12-04 Mark Wielaard <mark@klomp.org>
* debuginfod-client.c (debuginfod_query_server): Free winning_headers.
diff --git a/debuginfod/debuginfod.cxx b/debuginfod/debuginfod.cxx
index 0d3f0297..e38a551a 100644
--- a/debuginfod/debuginfod.cxx
+++ b/debuginfod/debuginfod.cxx
@@ -1,5 +1,6 @@
/* Debuginfo-over-http server.
Copyright (C) 2019-2021 Red Hat, Inc.
+ Copyright (C) 2021 Mark J. Wielaard <mark@klomp.org>
This file is part of elfutils.
This file is free software; you can redistribute it and/or modify
@@ -629,6 +630,9 @@ parse_opt (int key, char *arg,
////////////////////////////////////////////////////////////////////////
+static void add_mhd_response_header (struct MHD_Response *r,
+ const char *h, const char *v);
+
// represent errors that may get reported to an ostream and/or a libmicrohttpd connection
struct reportable_exception
@@ -646,7 +650,7 @@ struct reportable_exception
MHD_Response* r = MHD_create_response_from_buffer (message.size(),
(void*) message.c_str(),
MHD_RESPMEM_MUST_COPY);
- MHD_add_response_header (r, "Content-Type", "text/plain");
+ add_mhd_response_header (r, "Content-Type", "text/plain");
MHD_RESULT rc = MHD_queue_response (c, code, r);
MHD_destroy_response (r);
return rc;
@@ -1067,6 +1071,15 @@ conninfo (struct MHD_Connection * conn)
////////////////////////////////////////////////////////////////////////
+/* Wrapper for MHD_add_response_header that logs an error if we
+ couldn't add the specified header. */
+static void
+add_mhd_response_header (struct MHD_Response *r,
+ const char *h, const char *v)
+{
+ if (MHD_add_response_header (r, h, v) == MHD_NO)
+ obatched(clog) << "Error: couldn't add '" << h << "' header" << endl;
+}
static void
add_mhd_last_modified (struct MHD_Response *resp, time_t mtime)
@@ -1079,10 +1092,10 @@ add_mhd_last_modified (struct MHD_Response *resp, time_t mtime)
size_t rc = strftime (datebuf, sizeof (datebuf), "%a, %d %b %Y %T GMT",
nowp);
if (rc > 0 && rc < sizeof (datebuf))
- (void) MHD_add_response_header (resp, "Last-Modified", datebuf);
+ add_mhd_response_header (resp, "Last-Modified", datebuf);
}
- (void) MHD_add_response_header (resp, "Cache-Control", "public");
+ add_mhd_response_header (resp, "Cache-Control", "public");
}
@@ -1128,10 +1141,11 @@ handle_buildid_f_match (bool internal_req_t,
}
else
{
- MHD_add_response_header (r, "Content-Type", "application/octet-stream");
std::string file = b_source0.substr(b_source0.find_last_of("/")+1, b_source0.length());
- MHD_add_response_header (r, "X-DEBUGINFOD-SIZE", to_string(s.st_size).c_str() );
- MHD_add_response_header (r, "X-DEBUGINFOD-FILE", file.c_str() );
+ add_mhd_response_header (r, "Content-Type", "application/octet-stream");
+ add_mhd_response_header (r, "X-DEBUGINFOD-SIZE",
+ to_string(s.st_size).c_str());
+ add_mhd_response_header (r, "X-DEBUGINFOD-FILE", file.c_str());
add_mhd_last_modified (r, s.st_mtime);
if (verbose > 1)
obatched(clog) << "serving file " << b_source0 << endl;
@@ -1600,10 +1614,11 @@ handle_buildid_r_match (bool internal_req_p,
inc_metric ("http_responses_total","result","archive fdcache");
- MHD_add_response_header (r, "Content-Type", "application/octet-stream");
- MHD_add_response_header (r, "X-DEBUGINFOD-SIZE", to_string(fs.st_size).c_str());
- MHD_add_response_header (r, "X-DEBUGINFOD-ARCHIVE", b_source0.c_str());
- MHD_add_response_header (r, "X-DEBUGINFOD-FILE", b_source1.c_str());
+ add_mhd_response_header (r, "Content-Type", "application/octet-stream");
+ add_mhd_response_header (r, "X-DEBUGINFOD-SIZE",
+ to_string(fs.st_size).c_str());
+ add_mhd_response_header (r, "X-DEBUGINFOD-ARCHIVE", b_source0.c_str());
+ add_mhd_response_header (r, "X-DEBUGINFOD-FILE", b_source1.c_str());
add_mhd_last_modified (r, fs.st_mtime);
if (verbose > 1)
obatched(clog) << "serving fdcache archive " << b_source0 << " file " << b_source1 << endl;
@@ -1744,12 +1759,14 @@ handle_buildid_r_match (bool internal_req_p,
}
else
{
- MHD_add_response_header (r, "Content-Type", "application/octet-stream");
std::string file = b_source1.substr(b_source1.find_last_of("/")+1, b_source1.length());
- MHD_add_response_header (r, "X-DEBUGINFOD-SIZE", to_string(fs.st_size).c_str());
- MHD_add_response_header (r, "X-DEBUGINFOD-ARCHIVE", b_source0.c_str());
- MHD_add_response_header (r, "X-DEBUGINFOD-FILE", file.c_str());
-
+ add_mhd_response_header (r, "Content-Type",
+ "application/octet-stream");
+ add_mhd_response_header (r, "X-DEBUGINFOD-SIZE",
+ to_string(fs.st_size).c_str());
+ add_mhd_response_header (r, "X-DEBUGINFOD-ARCHIVE",
+ b_source0.c_str());
+ add_mhd_response_header (r, "X-DEBUGINFOD-FILE", file.c_str());
add_mhd_last_modified (r, archive_entry_mtime(e));
if (verbose > 1)
obatched(clog) << "serving archive " << b_source0 << " file " << b_source1 << endl;
@@ -2015,7 +2032,8 @@ and will not query the upstream servers");
auto r = MHD_create_response_from_fd ((uint64_t) s.st_size, fd);
if (r)
{
- MHD_add_response_header (r, "Content-Type", "application/octet-stream");
+ add_mhd_response_header (r, "Content-Type",
+ "application/octet-stream");
add_mhd_last_modified (r, s.st_mtime);
if (verbose > 1)
obatched(clog) << "serving file from upstream debuginfod/cache" << endl;
@@ -2166,8 +2184,11 @@ handle_metrics (off_t* size)
MHD_Response* r = MHD_create_response_from_buffer (os.size(),
(void*) os.c_str(),
MHD_RESPMEM_MUST_COPY);
- *size = os.size();
- MHD_add_response_header (r, "Content-Type", "text/plain");
+ if (r != NULL)
+ {
+ *size = os.size();
+ add_mhd_response_header (r, "Content-Type", "text/plain");
+ }
return r;
}
@@ -2179,8 +2200,11 @@ handle_root (off_t* size)
MHD_Response* r = MHD_create_response_from_buffer (version.size (),
(void *) version.c_str (),
MHD_RESPMEM_PERSISTENT);
- *size = version.size ();
- MHD_add_response_header (r, "Content-Type", "text/plain");
+ if (r != NULL)
+ {
+ *size = version.size ();
+ add_mhd_response_header (r, "Content-Type", "text/plain");
+ }
return r;
}
--
2.18.4
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