Hello,
Here is an updated patch, using memmove. Much smaller.
Thanks for the suggestions,
Noah Sanci
On Thu, Aug 26, 2021 at 5:02 PM Frank Ch. Eigler <f...@redhat.com> wrote:
>
> Hi -
>
> > /* PR28034 escape characters in completed url to %hh format. */
> > - char *escaped_string;
> > - escaped_string = curl_easy_escape(data[i].handle, filename, 0);
> > - if (!escaped_string)
> > + char escaped_string[PATH_MAX] = {'\0'};
> > + char *loc = (char *) filename;
> > + char *loc2;
> > + char *tmp;
> > + for(size_t j = 0; j < strlen(filename); ++j)
> > {
> > - rc = -ENOMEM;
> > - goto out2;
> > + loc2 = strstr(loc, "/");
> > + // If the first character is a '/'
> > [...]
>
> Holy cow that's a lot of work to do it this way.
> A couple of alternatives:
>
> - ditch curl_easy_escape :-( and use a
> malloc(strlen(x)*3)
> byte-by-byte copy from source string into destination
> if not [a-zA-Z0-9/.~] then %-escape
>
> or:
> - keep curl_easy_escape and postprocess
> byte-by-byte examine the result of curl_easy_escape
> - if seeing a "%2F", replace the % with a / and memmove the
> rest of the string 2 bytes ahead
>
> It shouldn't need strtok or strstr or a lot of logic or stuff like
> that really.
>
> - FChE
>
From de7e50955dba711aeee33196bf2bfea3c47696f7 Mon Sep 17 00:00:00 2001
From: Noah Sanci <nsa...@redhat.com>
Date: Fri, 16 Jul 2021 15:16:20 -0400
Subject: [PATCH] debuginfod: PR28034 - client-side %-escape url characters
When requesting some source files, some URL-inconvenient chars
sometimes pop up. Example from f33 libstdc++:
/buildid/44d8485cb75512c2ca5c8f70afbd475cae30af4f/source/usr/src/debug/
gcc-10.3.1-1.fc33.x86_64/obj-x86_64-redhat-linux/x86_64-redhat-linux/
libstdc++-v3/src/c++11/../../../../../libstdc++-v3/src/c++11/
condition_variable.cc
As this URL is passed into debuginfod's handler_cb, it appears that the
+ signs are helpfully unescaped to spaces by libmicrohttpd, which
'course breaks everything.
In order to ensure the server properly parses urls such as this one,
%-escape characters on the client side so that the correct url
is preserved and properly processed on the server side.
https://sourceware.org/bugzilla/show_bug.cgi?id=28034
Signed-off-by: Noah Sanci <nsa...@redhat.com>
---
debuginfod/debuginfod-client.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/debuginfod/debuginfod-client.c b/debuginfod/debuginfod-client.c
index 7d4b220f..eb49b583 100644
--- a/debuginfod/debuginfod-client.c
+++ b/debuginfod/debuginfod-client.c
@@ -905,13 +905,25 @@ debuginfod_query_server (debuginfod_client *c,
{
/* PR28034 escape characters in completed url to %hh format. */
char *escaped_string;
+ char *loc;
escaped_string = curl_easy_escape(data[i].handle, filename, 0);
if (!escaped_string)
{
rc = -ENOMEM;
goto out2;
}
- snprintf(data[i].url, PATH_MAX, "%s/%s/%s/%s", server_url,
+
+ loc = strstr(escaped_string, "%2F");
+ if (loc != NULL)
+ do
+ {
+ loc[0] = '/';
+ // pull the string back after replacement
+ memmove(loc+1,loc+3,strlen(loc+3));
+ escaped_string[strlen(escaped_string) - 1] = '\0';
+ escaped_string[strlen(escaped_string) - 1] = '\0';
+ } while( (loc = strstr(loc, "%2F")) );
+ snprintf(data[i].url, PATH_MAX, "%s/%s/%s%s", server_url,
build_id_bytes, type, escaped_string);
curl_free(escaped_string);
}
--
2.31.1
