container: look up executable by PATH

This commit is contained in:
criyle 2022-08-13 01:15:37 -07:00
parent 7e7babb354
commit 47ad6f0016
6 changed files with 87 additions and 11 deletions

View File

@ -4,7 +4,6 @@ type cmdType int8
const ( const (
cmdPing cmdType = iota + 1 cmdPing cmdType = iota + 1
cmdCopyIn
cmdOpen cmdOpen
cmdDelete cmdDelete
cmdReset cmdReset

View File

@ -17,7 +17,7 @@ func (c *containerServer) handleExecve(cmd *execCmd, msg unixsocket.Msg) error {
cred *syscall.Credential cred *syscall.Credential
) )
if cmd == nil { if cmd == nil {
return c.sendErrorReply("execve: no parameter provided") return c.sendErrorReply("handle: no parameter provided")
} }
if len(msg.Fds) > 0 { if len(msg.Fds) > 0 {
files = intSliceToUintptr(msg.Fds) files = intSliceToUintptr(msg.Fds)
@ -30,12 +30,20 @@ func (c *containerServer) handleExecve(cmd *execCmd, msg unixsocket.Msg) error {
// if fexecve, then the first fd must be executable // if fexecve, then the first fd must be executable
if cmd.FdExec { if cmd.FdExec {
if len(files) == 0 { if len(files) == 0 {
return fmt.Errorf("execve: expected fexecve fd") return c.sendErrorReply("handle: expected fexecve fd")
} }
execFile = files[0] execFile = files[0]
files = files[1:] files = files[1:]
} }
if len(cmd.Argv) > 0 {
exePath, err := lookPath(cmd.Argv[0], cmd.Env)
if err != nil {
return c.sendErrorReply("handle: %s: %v", cmd.Argv[0], err)
}
cmd.Argv[0] = exePath
}
syncFunc := func(pid int) error { syncFunc := func(pid int) error {
msg := unixsocket.Msg{ msg := unixsocket.Msg{
Cred: &syscall.Ucred{ Cred: &syscall.Ucred{

View File

@ -75,10 +75,16 @@ func (c *container) Execve(ctx context.Context, param ExecveParam) runner.Result
return errResult("execve: recvReply %v", err) return errResult("execve: recvReply %v", err)
} }
// if sync function did not involved // if sync function did not involved
if rep.Error != nil || msg.Cred == nil { if rep.Error != nil {
return errResult("execve: %v", rep.Error)
}
// if pid not received
if msg.Cred == nil {
// tell kill function to exit and sync // tell kill function to exit and sync
c.execveSyncKill() c.execveSyncKill()
return errResult("execve: no pid received or error %v", rep.Error) // tell err exec function to exit and sync
c.execveSyncKill()
return errResult("execve: no pid received")
} }
if param.SyncFunc != nil { if param.SyncFunc != nil {
if err := param.SyncFunc(int(msg.Cred.Pid)); err != nil { if err := param.SyncFunc(int(msg.Cred.Pid)); err != nil {

63
container/lookup_linux.go Normal file
View File

@ -0,0 +1,63 @@
package container
import (
"errors"
"io/fs"
"os"
"path/filepath"
"strings"
)
var (
errNotFound = errors.New("executable file not found in $PATH")
errNoPath = errors.New("no PATH environment variable provided for look up")
)
func findExecutable(file string) error {
d, err := os.Stat(file)
if err != nil {
return err
}
if m := d.Mode(); !m.IsDir() && m&0111 != 0 {
return nil
}
return fs.ErrPermission
}
func lookPath(name string, env []string) (string, error) {
// don't look if abs path provided
if filepath.Base(name) != name {
return name, nil
}
// don't look if exist in current dir
if err := findExecutable(name); err == nil {
return name, nil
}
path, err := findPath(env)
if err != nil {
return "", err
}
for _, dir := range path {
if dir == "" {
dir = "."
}
p := filepath.Join(dir, name)
if err := findExecutable(p); err == nil {
return p, nil
}
}
return "", errNotFound
}
func findPath(env []string) ([]string, error) {
// find PATH=
const pathPrefix = "PATH="
for _, s := range env {
if strings.HasPrefix(s, pathPrefix) {
return filepath.SplitList(s[len(pathPrefix):]), nil
}
}
return nil, errNoPath
}

4
go.mod
View File

@ -4,8 +4,8 @@ go 1.18
require ( require (
github.com/elastic/go-seccomp-bpf v1.2.0 github.com/elastic/go-seccomp-bpf v1.2.0
golang.org/x/net v0.0.0-20220809184613-07c6da5e1ced golang.org/x/net v0.0.0-20220812174116-3211cb980234
golang.org/x/sys v0.0.0-20220808155132-1c4a2a72c664 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab
) )
require github.com/pkg/errors v0.9.1 // indirect require github.com/pkg/errors v0.9.1 // indirect

8
go.sum
View File

@ -13,12 +13,12 @@ github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0
github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI= github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w= golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg= golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/net v0.0.0-20220809184613-07c6da5e1ced h1:3dYNDff0VT5xj+mbj2XucFst9WKk6PdGOrb9n+SbIvw= golang.org/x/net v0.0.0-20220812174116-3211cb980234 h1:RDqmgfe7SvlMWoqC3xwQ2blLO3fcWcxMa3eBLRdRW7E=
golang.org/x/net v0.0.0-20220809184613-07c6da5e1ced/go.mod h1:YDH+HFinaLZZlnHAfSS6ZXJJ9M9t4Dl22yv3iI2vPwk= golang.org/x/net v0.0.0-20220812174116-3211cb980234/go.mod h1:YDH+HFinaLZZlnHAfSS6ZXJJ9M9t4Dl22yv3iI2vPwk=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190405154228-4b34438f7a67/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= golang.org/x/sys v0.0.0-20190405154228-4b34438f7a67/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20220808155132-1c4a2a72c664 h1:v1W7bwXHsnLLloWYTVEdvGvA7BHMeBYsPcF0GLDxIRs= golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab h1:2QkjZIsXupsJbJIdSjjUOgWK3aEtzyuh2mPt3l/CkeU=
golang.org/x/sys v0.0.0-20220808155132-1c4a2a72c664/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ= golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0= gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI= gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=