tracker/bittorrent/request_sanitizer.go
2017-10-08 18:02:33 -04:00

61 lines
1.7 KiB
Go

package bittorrent
import (
"net"
log "github.com/sirupsen/logrus"
)
// ErrInvalidIP indicates an invalid IP for an Announce.
var ErrInvalidIP = ClientError("invalid IP")
// RequestSanitizer is used to replace unreasonable values in requests parsed
// from a frontend into sane values.
type RequestSanitizer struct {
MaxNumWant uint32 `yaml:"max_numwant"`
DefaultNumWant uint32 `yaml:"default_numwant"`
MaxScrapeInfoHashes uint32 `yaml:"max_scrape_infohashes"`
}
// SanitizeAnnounce enforces a max and default NumWant and coerces the peer's
// IP address into the proper format.
func (rs *RequestSanitizer) SanitizeAnnounce(r *AnnounceRequest) error {
if !r.NumWantProvided {
r.NumWant = rs.DefaultNumWant
} else if r.NumWant > rs.MaxNumWant {
r.NumWant = rs.MaxNumWant
}
if ip := r.Peer.IP.To4(); ip != nil {
r.Peer.IP.IP = ip
r.Peer.IP.AddressFamily = IPv4
} else if len(r.Peer.IP.IP) == net.IPv6len { // implies r.Peer.IP.To4() == nil
r.Peer.IP.AddressFamily = IPv6
} else {
return ErrInvalidIP
}
log.Debug("sanitized announce", rs, r)
return nil
}
// SanitizeScrape enforces a max number of infohashes for a single scrape
// request.
func (rs *RequestSanitizer) SanitizeScrape(r *ScrapeRequest) error {
if len(r.InfoHashes) > int(rs.MaxScrapeInfoHashes) {
r.InfoHashes = r.InfoHashes[:rs.MaxScrapeInfoHashes]
}
log.Debug("sanitized scrape", rs, r)
return nil
}
// LogFields renders the request sanitizer's configuration as a set of loggable
// fields.
func (rs *RequestSanitizer) LogFields() log.Fields {
return log.Fields{
"maxNumWant": rs.MaxNumWant,
"defaultNumWant": rs.DefaultNumWant,
"maxScrapeInfohashes": rs.MaxScrapeInfoHashes,
}
}