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|
package flags
import (
"flag"
"fmt"
"os"
"regexp"
"slices"
"strings"
"sync"
bpf "github.com/aquasecurity/libbpfgo"
)
var (
singleton Flags
once sync.Once
)
const flamegraphToolDefault = "$HOME/git/FlameGraph/flamegraph.pl"
var (
validCollapsedFields = []string{
"path",
"comm",
"tracepoint",
"pid",
"tid",
"flags",
}
validCollapsedCounts = []string{
"count",
"duration",
"durationToPrev",
"bytes",
}
)
type Flags struct {
PidFilter int
TidFilter int
EventMapSize int
CommFilter string
PathFilter string
PprofEnable bool
Duration int
// Tracepints flags
TracepointsToAttach []*regexp.Regexp
TracepointsToExclude []*regexp.Regexp
// Flamegraph flags
FlamegraphEnable bool
FlamegraphName string
// To convert ior data into collapsed format
IorDataFile string
CollapsedFields []string
CountField string
// To generate the Flamegraph SVGs
FlamegraphTool string
}
func Get() Flags {
return singleton
}
func Parse() {
once.Do(func() {
parse()
})
}
func parse() {
flag.IntVar(&singleton.PidFilter, "pid", -1, "Filter for processes ID")
flag.IntVar(&singleton.TidFilter, "tid", -1, "Filter for thread ID")
flag.IntVar(&singleton.EventMapSize, "mapSize", 4096*16, "BPF FD event ring buffer map size")
flag.IntVar(&singleton.Duration, "duration", 60, "Probe duration in seconds")
flag.StringVar(&singleton.CommFilter, "comm", "", "Command to filter for")
flag.StringVar(&singleton.PathFilter, "path", "", "Path to filter for")
flag.BoolVar(&singleton.PprofEnable, "pprof", false, "Enable profiling")
tracepointsToAttach := flag.String("tps", "", "Comma separated list regexes for tracepoints to load")
tracepointsToExclude := flag.String("tpsExclude", "", "Comma separated list regexes for tracepoints to exclude")
flag.BoolVar(&singleton.FlamegraphEnable, "flamegraph", false, "Enable flamegraph builder")
flag.StringVar(&singleton.FlamegraphName, "name", "default", "Name of the flamegraph, used to generate the SVG file")
flag.StringVar(&singleton.IorDataFile, "ior", "", "IOR data file to convert into collapsed format")
fields := flag.String("fields", "",
fmt.Sprintf("Comma separated list of fields to collapse, valid are: %v", validCollapsedFields))
flag.StringVar(&singleton.CountField, "count", "count",
fmt.Sprintf("Count field to collaps, valid are: %v", validCollapsedCounts))
// https://github.com/brendangregg/FlameGraph
flag.StringVar(&singleton.FlamegraphTool, "flamegraphTool",
"", "Path to the flamegraph tool (e.g. flamegraph.pl or inferno-flamegraph)")
flag.Parse()
if singleton.FlamegraphTool == "" {
singleton.FlamegraphTool = flamegraphToolDefault
}
singleton.TracepointsToAttach = extractTracepointFlags(*tracepointsToAttach)
singleton.TracepointsToExclude = extractTracepointFlags(*tracepointsToExclude)
// disabledTracepoints is a list of tracepoints that should not be attached due to wider isses.
// Here, the BPF programs wouldn't load otherwise due to CO-RE issues.
// TODO: Try out once in a while whether it works again with newer kernel versions.
furtherExcludes := []string{".*_name_to_handle_at"}
for _, exclude := range furtherExcludes {
fmt.Println("WARNING: Hard-excluding ", exclude)
singleton.TracepointsToExclude = append(singleton.TracepointsToExclude, regexp.MustCompile(exclude))
}
if *fields == "" {
singleton.CollapsedFields = []string{"pid", "path", "tracepoint"}
} else {
singleton.CollapsedFields = strings.Split(*fields, ",")
}
for _, field := range singleton.CollapsedFields {
if !slices.Contains(validCollapsedFields, field) {
fmt.Println("Invalid field for collapse:", field)
os.Exit(2)
}
}
if !slices.Contains(validCollapsedCounts, singleton.CountField) {
fmt.Println("Invalid count field:", singleton.CountField)
os.Exit(2)
}
}
func extractTracepointFlags(tracepoints string) (regexes []*regexp.Regexp) {
if len(tracepoints) == 0 {
return regexes
}
for _, name := range strings.Split(tracepoints, ",") {
re, err := regexp.Compile(name)
if err != nil {
fmt.Println("Unable to compile regex", name, ": ", err)
os.Exit(2)
}
regexes = append(regexes, re)
}
return regexes
}
func (flags Flags) ShouldIAttachTracepoint(tracepointName string) bool {
fmt.Println("ShouldIAttachTracepoint called with", tracepointName)
for _, re := range flags.TracepointsToExclude {
if re.MatchString(tracepointName) {
fmt.Println("Not attaching", tracepointName, "as excluded")
return false
}
}
if len(flags.TracepointsToAttach) == 0 {
fmt.Println("Attaching", tracepointName, "as none are explicitly incluced")
return true
}
for _, re := range flags.TracepointsToAttach {
if re.MatchString(tracepointName) {
fmt.Println("Attaching", tracepointName, "as included")
return true
}
}
fmt.Println("Not attaching", tracepointName, "as not includedd")
return false
}
func (flags Flags) SetBPF(bpfModule *bpf.Module) error {
// Ignore `ior` process itself from the filter
if err := bpfModule.InitGlobalVariable("IOR_PID_FILTER", uint32(os.Getpid())); err != nil {
return fmt.Errorf("unable set IOR_PID_FILTER: %w", err)
}
fmt.Println("Setting PID_FILTER to", flags.PidFilter)
if err := bpfModule.InitGlobalVariable("PID_FILTER", uint32(flags.PidFilter)); err != nil {
return fmt.Errorf("unable to set up PID_FILTER global variable: %w", err)
}
fmt.Println("Setting TID_FILTER to", flags.TidFilter)
if err := bpfModule.InitGlobalVariable("TID_FILTER", uint32(flags.TidFilter)); err != nil {
return fmt.Errorf("unable to set up TID_FILTER global variable: %w", err)
}
return nil
}
func (flags Flags) ResizeBPFMaps(bpfModule *bpf.Module) error {
if err := resizeBPFMap(bpfModule, "event_map", uint32(flags.EventMapSize)); err != nil {
return fmt.Errorf("event_map: %w", err)
}
return nil
}
func resizeBPFMap(module *bpf.Module, name string, size uint32) error {
m, err := module.GetMap(name)
if err != nil {
return err
}
if err = m.SetMaxEntries(size); err != nil {
return err
}
if actual := m.MaxEntries(); actual != size {
return fmt.Errorf("map resize to %d failed, expected %v, actual %v", size, size, actual)
}
return nil
}
|
