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From 91cda136ef27402256dbf85434374b43ab52d932 Mon Sep 17 00:00:00 2001
From: Phil Sutter <psutter@redhat.com>
Date: Fri, 11 Aug 2017 11:15:30 +0200
Subject: [PATCH] bpf: Make bytecode-file reading a little more robust
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1477491
Upstream Status: iproute2.git commit 3da3ebfca85b8
commit 3da3ebfca85b8f1e8252b898453d8cb383c5c398
Author: Phil Sutter <phil@nwl.cc>
Date: Wed Aug 2 14:57:56 2017 +0200
bpf: Make bytecode-file reading a little more robust
bpf_parse_string() will now correctly handle:
- Extraneous whitespace,
- OPs on multiple lines and
- overlong file names.
The added feature of allowing to have OPs on multiple lines (like e.g.
tcpdump prints them) is rather a side effect of fixing detection of
malformed bytecode files having random content on a second line, like
e.g.:
| 4,40 0 0 12,21 0 1 2048,6 0 0 262144,6 0 0 0
| foobar
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
---
lib/bpf.c | 32 ++++++++++++++++++++++++--------
1 file changed, 24 insertions(+), 8 deletions(-)
diff --git a/lib/bpf.c b/lib/bpf.c
index 04ee1ab..73dac5c 100644
--- a/lib/bpf.c
+++ b/lib/bpf.c
@@ -160,11 +160,11 @@ static int bpf_parse_string(char *arg, bool from_file, __u16 *bpf_len,
if (from_file) {
size_t tmp_len, op_len = sizeof("65535 255 255 4294967295,");
- char *tmp_string, *last;
+ char *tmp_string, *pos, c, c_prev = ' ';
FILE *fp;
tmp_len = sizeof("4096,") + BPF_MAXINSNS * op_len;
- tmp_string = calloc(1, tmp_len);
+ tmp_string = pos = calloc(1, tmp_len);
if (tmp_string == NULL)
return -ENOMEM;
@@ -175,17 +175,33 @@ static int bpf_parse_string(char *arg, bool from_file, __u16 *bpf_len,
return -ENOENT;
}
- if (!fgets(tmp_string, tmp_len, fp)) {
+ while ((c = fgetc(fp)) != EOF) {
+ switch (c) {
+ case '\n':
+ if (c_prev != ',')
+ *(pos++) = ',';
+ break;
+ case ' ':
+ case '\t':
+ if (c_prev != ' ')
+ *(pos++) = c;
+ break;
+ default:
+ *(pos++) = c;
+ }
+ if (pos - tmp_string == tmp_len)
+ break;
+ c_prev = c;
+ }
+
+ if (!feof(fp)) {
free(tmp_string);
fclose(fp);
- return -EIO;
+ return -E2BIG;
}
fclose(fp);
-
- last = &tmp_string[strlen(tmp_string) - 1];
- if (*last == '\n')
- *last = 0;
+ *pos = 0;
*need_release = true;
*bpf_string = tmp_string;
--
1.8.3.1