From: Frank Ch. Eigler Date: Tue, 10 Oct 2023 20:21:00 +0000 (-0400) Subject: PR30962: debuginfod: full paths for X-DEBUGINFOD-FILE/ARCHIVE response headers X-Git-Tag: elfutils-0.190~19 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=25932e63bd9dc5722d8d529f46e3540112df804f;p=thirdparty%2Felfutils.git PR30962: debuginfod: full paths for X-DEBUGINFOD-FILE/ARCHIVE response headers Previous code was inconsistent in offering basename versus full pathname for these headers. The documentation was not explicit on this issue. We now simplify by always passing full names back, and document this in the debuginfod.8 man page, along with pointers to how to use proxy front-end servers to strip them if needed. Signed-Off-By: Frank Ch. Eigler --- diff --git a/debuginfod/debuginfod.cxx b/debuginfod/debuginfod.cxx index e53228803..c11aeda1a 100644 --- a/debuginfod/debuginfod.cxx +++ b/debuginfod/debuginfod.cxx @@ -1876,11 +1876,10 @@ handle_buildid_f_match (bool internal_req_t, } else { - std::string file = b_source0.substr(b_source0.find_last_of("/")+1, b_source0.length()); 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_response_header (r, "X-DEBUGINFOD-FILE", b_source0.c_str()); add_mhd_last_modified (r, s.st_mtime); if (verbose > 1) obatched(clog) << "serving file " << b_source0 << " section=" << section << endl; @@ -2164,14 +2163,12 @@ handle_buildid_r_match (bool internal_req_p, } else { - std::string file = b_source1.substr(b_source1.find_last_of("/")+1, b_source1.length()); add_mhd_response_header (r, "Content-Type", "application/octet-stream"); add_mhd_response_header (r, "X-DEBUGINFOD-SIZE", to_string(archive_entry_size(e)).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_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, archive_entry_mtime(e)); if (verbose > 1) obatched(clog) << "serving archive " << b_source0 diff --git a/doc/debuginfod.8 b/doc/debuginfod.8 index d4316bec8..4f1f04b38 100644 --- a/doc/debuginfod.8 +++ b/doc/debuginfod.8 @@ -304,18 +304,35 @@ Unknown buildid / request combinations result in HTTP error codes. This file service resemblance is intentional, so that an installation can take advantage of standard HTTP management infrastructure. -Upon finding a file in an archive or simply in the database, some -custom http headers are added to the response. For files in the -database X-DEBUGINFOD-FILE and X-DEBUGINFOD-SIZE are added. -X-DEBUGINFOD-FILE is simply the unescaped filename and -X-DEBUGINFOD-SIZE is the size of the file. For files found in archives, -in addition to X-DEBUGINFOD-FILE and X-DEBUGINFOD-SIZE, -X-DEBUGINFOD-ARCHIVE is added. X-DEBUGINFOD-ARCHIVE is the name of the -archive the file was found in. - -There are three requests. In each case, the buildid is encoded as a -lowercase hexadecimal string. For example, for a program \fI/bin/ls\fP, -look at the ELF note GNU_BUILD_ID: +For most queries, some custom http headers are added to the response, +providing additional metadata about the buildid-related response. For example: + +.SAMPLE +% debuginfod-find -v debuginfo /bin/ls |& grep -i x-debuginfo +x-debuginfod-size: 502024 +x-debuginfod-archive: /mnt/fedora_koji_prod/koji/packages/coreutils/9.3/4.fc39/x86_64/coreutils-debuginfo-9.3-4.fc39.x86_64.rpm +x-debuginfod-file: /usr/lib/debug/usr/bin/ls-9.3-4.fc39.x86_64.debug +.ESAMPLE + +.TP +X-DEBUGINFOD-SIZE +The size of the file, in bytes. This may differ from the http Content-Length: +field (if present), due to compression in transit. + +.TP +X-DEBUGINFOD-FILE +The full path name of the file related to the given buildid. + +.TP +X-DEBUGINFOD-ARCHIVE +The full path name of the archive that contained the above file, if any. + + + + +There are a handful of buildid-related requests. In each case, the +buildid is encoded as a lowercase hexadecimal string. For example, +for a program \fI/bin/ls\fP, look at the ELF note GNU_BUILD_ID: .SAMPLE % readelf -n /bin/ls | grep -A4 build.id @@ -391,8 +408,7 @@ contents of the section, not an ELF file. This endpoint returns a Prometheus formatted text/plain dump of a variety of statistics about the operation of the debuginfod server. The exact set of metrics and their meanings may change in future -versions. Caution: configuration information (path names, versions) -may be disclosed. +versions. .SH DATA MANAGEMENT @@ -485,8 +501,16 @@ a denial-of-service in terms of RAM, CPU, disk I/O, or network I/O. If this is a problem, users are advised to install debuginfod with a HTTPS reverse-proxy front-end that enforces site policies for firewalling, authentication, integrity, authorization, and load -control. The \fI/metrics\fP webapi endpoint is probably not -appropriate for disclosure to the public. +control. + +Front-end proxies may elide sensitive path name components in +X-DEBUGINFOD-FILE/ARCHIVE response headers. For example, using Apache +httpd's \fBmod_headers\fP, you can remove the entire directory name +prefix: + +.SAMPLE +Header edit x-debuginfod-archive ".*/" "" +.ESAMPLE When relaying queries to upstream debuginfods, debuginfod \fBdoes not\fP include any particular security features. It trusts that the binaries diff --git a/tests/run-debuginfod-response-headers.sh b/tests/run-debuginfod-response-headers.sh index 8cb7b843d..fbb6a4842 100755 --- a/tests/run-debuginfod-response-headers.sh +++ b/tests/run-debuginfod-response-headers.sh @@ -78,8 +78,8 @@ tempfiles vlog-find$PORT1.1 errfiles vlog-find$PORT1.1 cat vlog-find$PORT1.1 grep 'Headers:' vlog-find$PORT1.1 -grep -i 'X-DEBUGINFOD-FILE: prog' vlog-find$PORT1.1 -grep -i 'X-DEBUGINFOD-SIZE: ' vlog-find$PORT1.1 +grep -i 'X-DEBUGINFOD-FILE: .*/prog' vlog-find$PORT1.1 +grep -i 'X-DEBUGINFOD-SIZE: ' vlog-find$PORT1.1 # Check to see if an executable file located in an archive prints the file's description and archive env DEBUGINFOD_URLS="http://127.0.0.1:"$PORT1 LD_LIBRARY_PATH=$ldpath ${abs_top_builddir}/debuginfod/debuginfod-find\ @@ -88,9 +88,9 @@ tempfiles vlog-find$PORT1.2 errfiles vlog-find$PORT1.2 cat vlog-find$PORT1.2 grep 'Headers:' vlog-find$PORT1.2 -grep -i 'X-DEBUGINFOD-FILE: ' vlog-find$PORT1.2 +grep -i 'X-DEBUGINFOD-FILE: .*/.*' vlog-find$PORT1.2 grep -i 'X-DEBUGINFOD-SIZE: ' vlog-find$PORT1.2 -grep -i 'X-DEBUGINFOD-ARCHIVE: ' vlog-find$PORT1.2 +grep -i 'X-DEBUGINFOD-ARCHIVE: .*/.*' vlog-find$PORT1.2 # Check that X-DEBUGINFOD-SIZE matches the size of each file for file in vlog-find$PORT1.1 vlog-find$PORT1.2