Support '==' and '!=' predicates for IPv4 address format;
for example
cd /sys/kernel/debug/tracing/events/tcp/tcp_receive_reset
echo "saddr == 127.0.0.1" > filter
Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
---
kernel/trace/trace_events_filter.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 64f1dfb72cb5..d8e08d3c3594 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1384,6 +1384,7 @@ static int parse_pred(const char *str, void *data,
unsigned long size;
unsigned long ip;
char num_buf[24]; /* Big enough to hold an address */
+ char scratch[4]; /* Big enough to hold an IPv4 address */
u8 *pred_val;
char *field_name;
char *name;
@@ -1646,6 +1647,24 @@ static int parse_pred(const char *str, void *data,
/* go past the last quote */
i++;
+ } else if (field->size == 4 &&
+ sscanf(&str[i], "%hhd.%hhd.%hhd.%hhd",
+ /* assume address in network byte order */
+ &scratch[0], &scratch[1], &scratch[2], &scratch[3]) == 4) {
+ /* For IPv4 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;
+ }
+ while (isdigit(str[i]) || str[i] == '.')
+ i++;
+ pred_val = kzalloc(field->size, GFP_KERNEL);
+ memcpy(pred_val, scratch, 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
