in pkg/tools/ssl/envoy.go [30:75]
func (r *Register) Envoy(envoySymbolAddrMap *ebpf.Map, sslWrite, sslWriteRet, sslRead, sslReadRet *ebpf.Program) {
r.addHandler("Envoy", func() (bool, error) {
moduleName := "/envoy"
processModules, err := r.findModules(moduleName)
if err != nil {
return false, err
}
envoyModule := processModules[moduleName]
if envoyModule == nil {
return false, nil
}
var readSymbol, writeSymbol bool
for _, sym := range envoyModule.Symbols {
if sym.Name == "SSL_read" {
readSymbol = true
} else if sym.Name == "SSL_write" {
writeSymbol = true
}
}
if !readSymbol || !writeSymbol {
log.Debugf("found the envoy process, but the ssl read or write symbol not exists, so ignore. read: %t, write: %t",
readSymbol, writeSymbol)
return false, nil
}
if envoySymbolAddrMap != nil {
addr := &EnvoySymbolAddress{
// for now the server field have fixed position
// https://github.com/google/boringssl/blob/master/ssl/internal.h#L3734-L3812
IsServerOffset: 164,
}
if err := envoySymbolAddrMap.Put(uint32(r.pid), addr); err != nil {
return false, fmt.Errorf("setting the envoy symbol offsets failure, pid: %d, error: %v", r.pid, err)
}
}
envoy := r.linker.OpenUProbeExeFile(envoyModule.Path)
envoy.AddLink("SSL_write", sslWrite, sslWriteRet)
envoy.AddLink("SSL_read", sslRead, sslReadRet)
if e := r.linker.HasError(); e != nil {
return false, e
}
return true, nil
})
}