1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
#include <linux/blkdev.h>
#include <uapi/linux/ptrace.h>
/**
* @brief Helper method to filter based on the specified inputString.
* @param inputString The operation input string to check against the filter.
* @return True if the specified inputString starts with the hard-coded filter string; otherwise, false.
*/
static inline bool filter(char const* inputString)
{
static const char* null_ptr = 0x0;
static const char null_terminator = '\0';
static const char filter_string[] = "FILTER_STRING"; ///< The filter string is replaced by python code.
if (null_ptr == inputString) {
return false;
}
// Compare until (not including) the null-terminator for filter_string
for (int i = 0; i < sizeof(filter_string) - 1; ++i) {
char c1 = *inputString++;
if (null_terminator == c1) {
return false; // If the null-terminator for inputString was reached, it can not be equal to filter_string.
}
char c2 = filter_string[i];
if (c1 != c2) {
return false;
}
}
return true;
}
/**
* @brief Contains the operation start data to trace.
*/
struct start_data_t
{
u64 operation_id; ///< The id of the operation.
char input[64]; ///< The input string of the request.
u64 start; ///< Timestamp of the start operation (start timestamp).
};
/**
* @brief Contains the operation start data.
* key: the operation id.
* value: The operation start latency data.
*/
BPF_HASH(start_hash, u64, struct start_data_t);
/**
* @brief Reads the operation request arguments and stores the start data in the hash.
* @param ctx The BPF context.
*/
int trace_operation_start(struct pt_regs* ctx)
{
struct start_data_t start_data = {};
bpf_usdt_readarg_p(2, ctx, &start_data.input, sizeof(start_data.input));
FILTER_STATEMENT ///< Replaced by python code.
bpf_usdt_readarg(1, ctx, &start_data.operation_id);
start_data.start = bpf_ktime_get_ns();
start_hash.update(&start_data.operation_id, &start_data);
return 0;
}
|
