From: Alan Maguire <alan.maguire@oracle.com>
To: rostedt@goodmis.org, mhiramat@kernel.org
Cc: corbet@lwn.net, shuah@kernel.org,
linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
Alan Maguire <alan.maguire@oracle.com>
Subject: [PATCH v2 tracing 3/6] tracing: support IPv6 filter predicates
Date: Fri, 28 Apr 2023 16:34:46 +0100 [thread overview]
Message-ID: <1682696089-27937-4-git-send-email-alan.maguire@oracle.com> (raw)
In-Reply-To: <1682696089-27937-1-git-send-email-alan.maguire@oracle.com>
Support '==' and '!=' predicates for IPv6 addresses;
for example
cd /sys/kernel/debug/tracing/events/tcp/tcp_receive_reset
echo "saddr_v6 == ::1" > filter
or equivalently
echo "saddr_v6 == 0:0:0:0:0:0:0:1" > filter
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
---
kernel/trace/trace_events_filter.c | 73 ++++++++++++++++++++++++++++++
1 file changed, 73 insertions(+)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index d8e08d3c3594..e2521574f3c4 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1665,6 +1665,79 @@ static int parse_pred(const char *str, void *data,
if (pred->op == OP_NE)
pred->not = 1;
+ } else if (field->size == 16 &&
+ (str[i] == ':' ||
+ (isalnum(str[i]) && tolower(str[i + 1]) != 'x'))) {
+ u8 j, gap_size, gap = 0, gap_count = 0, index = 0;
+ u16 tmp_v6addr[8] = {};
+ u16 v6addr[8] = {};
+
+ /* For IPv6 addresses, only '==' or '!=' are supported. */
+ if (pred->op != OP_EQ && pred->op != OP_NE) {
+ parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
+ goto err_free;
+ }
+ /* Store the u16s in the address string consecutively in
+ * tmp_v6addr while tracking the presence of a "::" (if any)
+ * in the IPv6 address string; we will use its location
+ * to determine how many u16s it represents (the gap_size
+ * below). Only one "::" is allowed in an IPv6 address
+ * string.
+ */
+ while (isalnum(str[i]) || str[i] == ':') {
+ switch (str[i]) {
+ case ':':
+ i++;
+ /* mark "::" index by setting gap */
+ if (str[i] == ':') {
+ gap = index;
+ gap_count++;
+ i++;
+ }
+ if (gap_count > 1) {
+ parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP,
+ pos + s);
+ goto err_free;
+ }
+ break;
+ default:
+ if (sscanf(&str[i], "%hx", &tmp_v6addr[index]) != 1) {
+ parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP,
+ pos + s);
+ goto err_free;
+ }
+ index++;
+ while (isalnum(str[i]))
+ i++;
+ break;
+ }
+ }
+ /* The gap_size here represents the number of u16s the "::"
+ * represents; for ::1 the gap size is 7, for feed::face
+ * it is 6, etc.
+ */
+ gap_size = 8 - index;
+ index = 0;
+ for (j = 0; j < 8; ) {
+ if (gap_size > 0 && j == gap) {
+ j += gap_size;
+ } else {
+#ifdef __BIG_ENDIAN
+ v6addr[j++] = tmp_v6addr[index];
+#else
+ v6addr[j++] = ((tmp_v6addr[index] & 0xff) << 8) +
+ ((tmp_v6addr[index] & 0xff00) >> 8);
+#endif
+ index++;
+ }
+ }
+ pred_val = kzalloc(field->size, GFP_KERNEL);
+ memcpy(pred_val, v6addr, field->size);
+ pred->val = (u64)pred_val;
+ pred->fn_num = FILTER_PRED_FN_MEMCMP;
+ if (pred->op == OP_NE)
+ pred->not = 1;
+
} else if (str[i] == '0' && tolower(str[i + 1]) == 'x' &&
field->size > 8) {
/* For sizes > 8 bytes, we store hex bytes for comparison;
--
2.31.1
next prev parent reply other threads:[~2023-04-28 15:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-28 15:34 [PATCH v2 tracing 0/6] tracing: additional filter predicates Alan Maguire
2023-04-28 15:34 ` [PATCH v2 tracing 1/6] tracing: support > 8 byte array " Alan Maguire
2023-04-28 15:34 ` [PATCH v2 tracing 2/6] tracing: support IPv4 address filter predicate Alan Maguire
2023-04-28 15:34 ` Alan Maguire [this message]
2023-06-09 21:12 ` [PATCH v2 tracing 3/6] tracing: support IPv6 filter predicates Steven Rostedt
2023-06-09 21:15 ` Steven Rostedt
2023-04-28 15:34 ` [PATCH v2 tracing 4/6] tracing: support MAC address " Alan Maguire
2023-04-28 15:34 ` [PATCH v2 tracing 5/6] selftests/ftrace: add test coverage for " Alan Maguire
2023-04-28 15:34 ` [PATCH v2 tracing 6/6] tracing: document IPv4, IPv6, MAC address and > 8 byte numeric filtering support Alan Maguire
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1682696089-27937-4-git-send-email-alan.maguire@oracle.com \
--to=alan.maguire@oracle.com \
--cc=corbet@lwn.net \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=mhiramat@kernel.org \
--cc=rostedt@goodmis.org \
--cc=shuah@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).