Lynx
Table of Contents
Lynx is a simple unveil & pledge wrapper. It returns nil on unsupported systems, currently only OpenBSD is supported.
Project Home | Lynx |
Source Code | Andinus / Lynx |
GitHub (Mirror) | Lynx - GitHub |
Why use lynx?
- UnveilPaths & UnveilCommands: unix package provides simple Unveil syscalls so this is useful because you don't have to write these functions yourself manually in every project.
- lynx manages build flags for you, which means that lynx will return nil on unsupported systems whereas you have handle that yourself in unix package.
Note: Unveil, UnveilPaths & UnveilCommands ignore some errors, look at examples before using them.
Examples
UnveilPaths / UnveilPathsStrict
UnveilPaths takes a map of path, permission & unveils them one by one, it will return an error if unveil fails at any step. "no such file or directory" error is ignored, if you want to get that error too then use UnveilPathsStrict.
package main import "git.tilde.institute/andinus/lynx" func main() { paths := make(map[string]string) paths["/home"] = "r" paths["/dev/null"] = "rw" paths["/etc/examples"] = "rwc" paths["/root"] = "rwcx" err = lynx.UnveilPaths(paths) if err != nil { log.Fatal(err) } // This will return an error if the path doesn't exist. err = lynx.UnveilPathsStrict(paths) if err != nil { log.Fatal(err) } }
UnveilCommands
UnveilCommands takes a slice of commands & unveils them one by one, it will return an error if unveil fails at any step. "no such file or directory" error is ignored because binaries are not placed in every PATH.
Default permission is "rx".
package main import "git.tilde.institute/andinus/lynx" func main() { commands := []string{"cd", "ls", "rm"} err = lynx.UnveilCommands(commands) if err != nil { log.Fatal(err) } }
UnveilBlock
UnveilBlock is just a wrapper around unix.UnveilBlock, it does nothing extra. You should use unix.UnveilBlock.
package main import "git.tilde.institute/andinus/lynx" func main() { // Block further unveil calls. err = lynx.UnveilBlock() if err != nil { log.Fatal(err) } }
Unveil / UnveilStrict
Unveil takes a path, permission & unveils it, it will return an error if unveil fails at any step. "no such file or directory" error is ignored, if you want to get that error too then use UnveilStrict.
package main import "git.tilde.institute/andinus/lynx" func main() { path := "/dev/null" flags := "rw" err = lynx.Unveil(path, flags) if err != nil { log.Fatal(err) } // This will return an error if the path doesn't exist. err = lynx.UnveilStrict(path, flags) if err != nil { log.Fatal(err) } }
Pledge / PledgePromises / PledgeExecpromises
These are simple wrappers to unix package functions. They add nothing extra, you could simply change lynx.Pledge to unix.Pledge & it would just work.
package main import "git.tilde.institute/andinus/lynx" func main() { promises := "stdio unveil" execpromises := "stdio" err = lynx.Pledge(promises, execpromises) if err != nil { log.Fatal(err) } // Drop promises. promises = "stdio" err = lynx.PledgePromises(promises) if err != nil { log.Fatal(err) } // Drop execpromises. execpromises = "" err = lynx.PledgeExecpromises(execpromises) if err != nil { log.Fatal(err) } }