forked from caddyserver/caddy
/
maxrequestbody.go
178 lines (150 loc) · 3.88 KB
/
maxrequestbody.go
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package maxrequestbody
import (
"errors"
"sort"
"strconv"
"strings"
"github.com/mholt/caddy"
"github.com/mholt/caddy/caddyhttp/httpserver"
)
const (
serverType = "http"
pluginName = "maxrequestbody"
)
func init() {
caddy.RegisterPlugin(pluginName, caddy.Plugin{
ServerType: serverType,
Action: setupMaxRequestBody,
})
}
// pathLimitUnparsed is a PathLimit before it's parsed
type pathLimitUnparsed struct {
Path string
Limit string
}
func setupMaxRequestBody(c *caddy.Controller) error {
config := httpserver.GetConfig(c)
if !c.Next() {
return c.ArgErr()
}
args := c.RemainingArgs()
argList := []pathLimitUnparsed{}
switch len(args) {
case 0:
// Format: { <path> <limit> ... }
for c.NextBlock() {
path := c.Val()
if !c.NextArg() {
// Uneven pairing of path/limit
return c.ArgErr()
}
argList = append(argList, pathLimitUnparsed{
Path: path,
Limit: c.Val(),
})
}
case 1:
// Format: <limit>
argList = []pathLimitUnparsed{{
Path: "/",
Limit: args[0],
}}
case 2:
// Format: <path> <limit>
argList = []pathLimitUnparsed{{
Path: args[0],
Limit: args[1],
}}
default:
return c.ArgErr()
}
pathLimit, err := parseArguments(argList)
if err != nil {
return c.ArgErr()
}
SortPathLimits(pathLimit)
config.MaxRequestBodySizes = pathLimit
return nil
}
func parseArguments(args []pathLimitUnparsed) ([]httpserver.PathLimit, error) {
pathLimit := []httpserver.PathLimit{}
for _, pair := range args {
size := parseSize(pair.Limit)
if size < 1 { // also disallow size = 0
return pathLimit, errors.New("Parse failed")
}
pathLimit = addPathLimit(pathLimit, pair.Path, size)
}
return pathLimit, nil
}
var validUnits = []struct {
symbol string
multiplier int64
}{
{"KB", 1024},
{"MB", 1024 * 1024},
{"GB", 1024 * 1024 * 1024},
{"B", 1},
{"", 1}, // defaulting to "B"
}
// parseSize parses the given string as size limit
// Size are positive numbers followed by a unit (case insensitive)
// Allowed units: "B" (bytes), "KB" (kilo), "MB" (mega), "GB" (giga)
// If the unit is omitted, "b" is assumed
// Returns the parsed size in bytes, or -1 if cannot parse
func parseSize(sizeStr string) int64 {
sizeStr = strings.ToUpper(sizeStr)
for _, unit := range validUnits {
if strings.HasSuffix(sizeStr, unit.symbol) {
size, err := strconv.ParseInt(sizeStr[0:len(sizeStr)-len(unit.symbol)], 10, 64)
if err != nil {
return -1
}
return size * unit.multiplier
}
}
// Unreachable code
return -1
}
// addPathLimit appends the path-to-request body limit mapping to pathLimit
// Slashes are checked and added to path if necessary. Duplicates are ignored.
func addPathLimit(pathLimit []httpserver.PathLimit, path string, limit int64) []httpserver.PathLimit {
// Enforces preceding slash
if path[0] != '/' {
path = "/" + path
}
// Use the last value if there are duplicates
for i, p := range pathLimit {
if p.Path == path {
pathLimit[i].Limit = limit
return pathLimit
}
}
return append(pathLimit, httpserver.PathLimit{Path: path, Limit: limit})
}
// SortPathLimits sort pathLimits by their paths length, longest first
func SortPathLimits(pathLimits []httpserver.PathLimit) {
sorter := &pathLimitSorter{
pathLimits: pathLimits,
by: LengthDescending,
}
sort.Sort(sorter)
}
// structs and methods implementing the sorting interfaces for PathLimit
type pathLimitSorter struct {
pathLimits []httpserver.PathLimit
by func(p1, p2 *httpserver.PathLimit) bool
}
func (s *pathLimitSorter) Len() int {
return len(s.pathLimits)
}
func (s *pathLimitSorter) Swap(i, j int) {
s.pathLimits[i], s.pathLimits[j] = s.pathLimits[j], s.pathLimits[i]
}
func (s *pathLimitSorter) Less(i, j int) bool {
return s.by(&s.pathLimits[i], &s.pathLimits[j])
}
// LengthDescending is the comparator for SortPathLimits
func LengthDescending(p1, p2 *httpserver.PathLimit) bool {
return len(p1.Path) > len(p2.Path)
}