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author | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
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committer | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
commit | a031b83a09a8628435317a03f199cdc18b78262f (patch) | |
tree | bc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/github.com/opencontainers/runc/libcontainer/user | |
parent | 2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff) | |
download | podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.gz podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.bz2 podman-a031b83a09a8628435317a03f199cdc18b78262f.zip |
Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/github.com/opencontainers/runc/libcontainer/user')
4 files changed, 620 insertions, 0 deletions
diff --git a/vendor/github.com/opencontainers/runc/libcontainer/user/lookup.go b/vendor/github.com/opencontainers/runc/libcontainer/user/lookup.go new file mode 100644 index 000000000..95e9eebc0 --- /dev/null +++ b/vendor/github.com/opencontainers/runc/libcontainer/user/lookup.go @@ -0,0 +1,95 @@ +package user + +import ( + "errors" +) + +var ( + // The current operating system does not provide the required data for user lookups. + ErrUnsupported = errors.New("user lookup: operating system does not provide passwd-formatted data") + // No matching entries found in file. + ErrNoPasswdEntries = errors.New("no matching entries in passwd file") + ErrNoGroupEntries = errors.New("no matching entries in group file") +) + +func lookupUser(filter func(u User) bool) (User, error) { + // Get operating system-specific passwd reader-closer. + passwd, err := GetPasswd() + if err != nil { + return User{}, err + } + defer passwd.Close() + + // Get the users. + users, err := ParsePasswdFilter(passwd, filter) + if err != nil { + return User{}, err + } + + // No user entries found. + if len(users) == 0 { + return User{}, ErrNoPasswdEntries + } + + // Assume the first entry is the "correct" one. + return users[0], nil +} + +// LookupUser looks up a user by their username in /etc/passwd. If the user +// cannot be found (or there is no /etc/passwd file on the filesystem), then +// LookupUser returns an error. +func LookupUser(username string) (User, error) { + return lookupUser(func(u User) bool { + return u.Name == username + }) +} + +// LookupUid looks up a user by their user id in /etc/passwd. If the user cannot +// be found (or there is no /etc/passwd file on the filesystem), then LookupId +// returns an error. +func LookupUid(uid int) (User, error) { + return lookupUser(func(u User) bool { + return u.Uid == uid + }) +} + +func lookupGroup(filter func(g Group) bool) (Group, error) { + // Get operating system-specific group reader-closer. + group, err := GetGroup() + if err != nil { + return Group{}, err + } + defer group.Close() + + // Get the users. + groups, err := ParseGroupFilter(group, filter) + if err != nil { + return Group{}, err + } + + // No user entries found. + if len(groups) == 0 { + return Group{}, ErrNoGroupEntries + } + + // Assume the first entry is the "correct" one. + return groups[0], nil +} + +// LookupGroup looks up a group by its name in /etc/group. If the group cannot +// be found (or there is no /etc/group file on the filesystem), then LookupGroup +// returns an error. +func LookupGroup(groupname string) (Group, error) { + return lookupGroup(func(g Group) bool { + return g.Name == groupname + }) +} + +// LookupGid looks up a group by its group id in /etc/group. If the group cannot +// be found (or there is no /etc/group file on the filesystem), then LookupGid +// returns an error. +func LookupGid(gid int) (Group, error) { + return lookupGroup(func(g Group) bool { + return g.Gid == gid + }) +} diff --git a/vendor/github.com/opencontainers/runc/libcontainer/user/lookup_unix.go b/vendor/github.com/opencontainers/runc/libcontainer/user/lookup_unix.go new file mode 100644 index 000000000..c2bb9ec90 --- /dev/null +++ b/vendor/github.com/opencontainers/runc/libcontainer/user/lookup_unix.go @@ -0,0 +1,46 @@ +// +build darwin dragonfly freebsd linux netbsd openbsd solaris + +package user + +import ( + "io" + "os" + + "golang.org/x/sys/unix" +) + +// Unix-specific path to the passwd and group formatted files. +const ( + unixPasswdPath = "/etc/passwd" + unixGroupPath = "/etc/group" +) + +func GetPasswdPath() (string, error) { + return unixPasswdPath, nil +} + +func GetPasswd() (io.ReadCloser, error) { + return os.Open(unixPasswdPath) +} + +func GetGroupPath() (string, error) { + return unixGroupPath, nil +} + +func GetGroup() (io.ReadCloser, error) { + return os.Open(unixGroupPath) +} + +// CurrentUser looks up the current user by their user id in /etc/passwd. If the +// user cannot be found (or there is no /etc/passwd file on the filesystem), +// then CurrentUser returns an error. +func CurrentUser() (User, error) { + return LookupUid(unix.Getuid()) +} + +// CurrentGroup looks up the current user's group by their primary group id's +// entry in /etc/passwd. If the group cannot be found (or there is no +// /etc/group file on the filesystem), then CurrentGroup returns an error. +func CurrentGroup() (Group, error) { + return LookupGid(unix.Getgid()) +} diff --git a/vendor/github.com/opencontainers/runc/libcontainer/user/lookup_unsupported.go b/vendor/github.com/opencontainers/runc/libcontainer/user/lookup_unsupported.go new file mode 100644 index 000000000..4a8d00acb --- /dev/null +++ b/vendor/github.com/opencontainers/runc/libcontainer/user/lookup_unsupported.go @@ -0,0 +1,38 @@ +// +build !darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd,!solaris + +package user + +import ( + "io" + "syscall" +) + +func GetPasswdPath() (string, error) { + return "", ErrUnsupported +} + +func GetPasswd() (io.ReadCloser, error) { + return nil, ErrUnsupported +} + +func GetGroupPath() (string, error) { + return "", ErrUnsupported +} + +func GetGroup() (io.ReadCloser, error) { + return nil, ErrUnsupported +} + +// CurrentUser looks up the current user by their user id in /etc/passwd. If the +// user cannot be found (or there is no /etc/passwd file on the filesystem), +// then CurrentUser returns an error. +func CurrentUser() (User, error) { + return LookupUid(syscall.Getuid()) +} + +// CurrentGroup looks up the current user's group by their primary group id's +// entry in /etc/passwd. If the group cannot be found (or there is no +// /etc/group file on the filesystem), then CurrentGroup returns an error. +func CurrentGroup() (Group, error) { + return LookupGid(syscall.Getgid()) +} diff --git a/vendor/github.com/opencontainers/runc/libcontainer/user/user.go b/vendor/github.com/opencontainers/runc/libcontainer/user/user.go new file mode 100644 index 000000000..8962cab33 --- /dev/null +++ b/vendor/github.com/opencontainers/runc/libcontainer/user/user.go @@ -0,0 +1,441 @@ +package user + +import ( + "bufio" + "fmt" + "io" + "os" + "strconv" + "strings" +) + +const ( + minId = 0 + maxId = 1<<31 - 1 //for 32-bit systems compatibility +) + +var ( + ErrRange = fmt.Errorf("uids and gids must be in range %d-%d", minId, maxId) +) + +type User struct { + Name string + Pass string + Uid int + Gid int + Gecos string + Home string + Shell string +} + +type Group struct { + Name string + Pass string + Gid int + List []string +} + +func parseLine(line string, v ...interface{}) { + if line == "" { + return + } + + parts := strings.Split(line, ":") + for i, p := range parts { + // Ignore cases where we don't have enough fields to populate the arguments. + // Some configuration files like to misbehave. + if len(v) <= i { + break + } + + // Use the type of the argument to figure out how to parse it, scanf() style. + // This is legit. + switch e := v[i].(type) { + case *string: + *e = p + case *int: + // "numbers", with conversion errors ignored because of some misbehaving configuration files. + *e, _ = strconv.Atoi(p) + case *[]string: + // Comma-separated lists. + if p != "" { + *e = strings.Split(p, ",") + } else { + *e = []string{} + } + default: + // Someone goof'd when writing code using this function. Scream so they can hear us. + panic(fmt.Sprintf("parseLine only accepts {*string, *int, *[]string} as arguments! %#v is not a pointer!", e)) + } + } +} + +func ParsePasswdFile(path string) ([]User, error) { + passwd, err := os.Open(path) + if err != nil { + return nil, err + } + defer passwd.Close() + return ParsePasswd(passwd) +} + +func ParsePasswd(passwd io.Reader) ([]User, error) { + return ParsePasswdFilter(passwd, nil) +} + +func ParsePasswdFileFilter(path string, filter func(User) bool) ([]User, error) { + passwd, err := os.Open(path) + if err != nil { + return nil, err + } + defer passwd.Close() + return ParsePasswdFilter(passwd, filter) +} + +func ParsePasswdFilter(r io.Reader, filter func(User) bool) ([]User, error) { + if r == nil { + return nil, fmt.Errorf("nil source for passwd-formatted data") + } + + var ( + s = bufio.NewScanner(r) + out = []User{} + ) + + for s.Scan() { + if err := s.Err(); err != nil { + return nil, err + } + + line := strings.TrimSpace(s.Text()) + if line == "" { + continue + } + + // see: man 5 passwd + // name:password:UID:GID:GECOS:directory:shell + // Name:Pass:Uid:Gid:Gecos:Home:Shell + // root:x:0:0:root:/root:/bin/bash + // adm:x:3:4:adm:/var/adm:/bin/false + p := User{} + parseLine(line, &p.Name, &p.Pass, &p.Uid, &p.Gid, &p.Gecos, &p.Home, &p.Shell) + + if filter == nil || filter(p) { + out = append(out, p) + } + } + + return out, nil +} + +func ParseGroupFile(path string) ([]Group, error) { + group, err := os.Open(path) + if err != nil { + return nil, err + } + + defer group.Close() + return ParseGroup(group) +} + +func ParseGroup(group io.Reader) ([]Group, error) { + return ParseGroupFilter(group, nil) +} + +func ParseGroupFileFilter(path string, filter func(Group) bool) ([]Group, error) { + group, err := os.Open(path) + if err != nil { + return nil, err + } + defer group.Close() + return ParseGroupFilter(group, filter) +} + +func ParseGroupFilter(r io.Reader, filter func(Group) bool) ([]Group, error) { + if r == nil { + return nil, fmt.Errorf("nil source for group-formatted data") + } + + var ( + s = bufio.NewScanner(r) + out = []Group{} + ) + + for s.Scan() { + if err := s.Err(); err != nil { + return nil, err + } + + text := s.Text() + if text == "" { + continue + } + + // see: man 5 group + // group_name:password:GID:user_list + // Name:Pass:Gid:List + // root:x:0:root + // adm:x:4:root,adm,daemon + p := Group{} + parseLine(text, &p.Name, &p.Pass, &p.Gid, &p.List) + + if filter == nil || filter(p) { + out = append(out, p) + } + } + + return out, nil +} + +type ExecUser struct { + Uid int + Gid int + Sgids []int + Home string +} + +// GetExecUserPath is a wrapper for GetExecUser. It reads data from each of the +// given file paths and uses that data as the arguments to GetExecUser. If the +// files cannot be opened for any reason, the error is ignored and a nil +// io.Reader is passed instead. +func GetExecUserPath(userSpec string, defaults *ExecUser, passwdPath, groupPath string) (*ExecUser, error) { + var passwd, group io.Reader + + if passwdFile, err := os.Open(passwdPath); err == nil { + passwd = passwdFile + defer passwdFile.Close() + } + + if groupFile, err := os.Open(groupPath); err == nil { + group = groupFile + defer groupFile.Close() + } + + return GetExecUser(userSpec, defaults, passwd, group) +} + +// GetExecUser parses a user specification string (using the passwd and group +// readers as sources for /etc/passwd and /etc/group data, respectively). In +// the case of blank fields or missing data from the sources, the values in +// defaults is used. +// +// GetExecUser will return an error if a user or group literal could not be +// found in any entry in passwd and group respectively. +// +// Examples of valid user specifications are: +// * "" +// * "user" +// * "uid" +// * "user:group" +// * "uid:gid +// * "user:gid" +// * "uid:group" +// +// It should be noted that if you specify a numeric user or group id, they will +// not be evaluated as usernames (only the metadata will be filled). So attempting +// to parse a user with user.Name = "1337" will produce the user with a UID of +// 1337. +func GetExecUser(userSpec string, defaults *ExecUser, passwd, group io.Reader) (*ExecUser, error) { + if defaults == nil { + defaults = new(ExecUser) + } + + // Copy over defaults. + user := &ExecUser{ + Uid: defaults.Uid, + Gid: defaults.Gid, + Sgids: defaults.Sgids, + Home: defaults.Home, + } + + // Sgids slice *cannot* be nil. + if user.Sgids == nil { + user.Sgids = []int{} + } + + // Allow for userArg to have either "user" syntax, or optionally "user:group" syntax + var userArg, groupArg string + parseLine(userSpec, &userArg, &groupArg) + + // Convert userArg and groupArg to be numeric, so we don't have to execute + // Atoi *twice* for each iteration over lines. + uidArg, uidErr := strconv.Atoi(userArg) + gidArg, gidErr := strconv.Atoi(groupArg) + + // Find the matching user. + users, err := ParsePasswdFilter(passwd, func(u User) bool { + if userArg == "" { + // Default to current state of the user. + return u.Uid == user.Uid + } + + if uidErr == nil { + // If the userArg is numeric, always treat it as a UID. + return uidArg == u.Uid + } + + return u.Name == userArg + }) + + // If we can't find the user, we have to bail. + if err != nil && passwd != nil { + if userArg == "" { + userArg = strconv.Itoa(user.Uid) + } + return nil, fmt.Errorf("unable to find user %s: %v", userArg, err) + } + + var matchedUserName string + if len(users) > 0 { + // First match wins, even if there's more than one matching entry. + matchedUserName = users[0].Name + user.Uid = users[0].Uid + user.Gid = users[0].Gid + user.Home = users[0].Home + } else if userArg != "" { + // If we can't find a user with the given username, the only other valid + // option is if it's a numeric username with no associated entry in passwd. + + if uidErr != nil { + // Not numeric. + return nil, fmt.Errorf("unable to find user %s: %v", userArg, ErrNoPasswdEntries) + } + user.Uid = uidArg + + // Must be inside valid uid range. + if user.Uid < minId || user.Uid > maxId { + return nil, ErrRange + } + + // Okay, so it's numeric. We can just roll with this. + } + + // On to the groups. If we matched a username, we need to do this because of + // the supplementary group IDs. + if groupArg != "" || matchedUserName != "" { + groups, err := ParseGroupFilter(group, func(g Group) bool { + // If the group argument isn't explicit, we'll just search for it. + if groupArg == "" { + // Check if user is a member of this group. + for _, u := range g.List { + if u == matchedUserName { + return true + } + } + return false + } + + if gidErr == nil { + // If the groupArg is numeric, always treat it as a GID. + return gidArg == g.Gid + } + + return g.Name == groupArg + }) + if err != nil && group != nil { + return nil, fmt.Errorf("unable to find groups for spec %v: %v", matchedUserName, err) + } + + // Only start modifying user.Gid if it is in explicit form. + if groupArg != "" { + if len(groups) > 0 { + // First match wins, even if there's more than one matching entry. + user.Gid = groups[0].Gid + } else { + // If we can't find a group with the given name, the only other valid + // option is if it's a numeric group name with no associated entry in group. + + if gidErr != nil { + // Not numeric. + return nil, fmt.Errorf("unable to find group %s: %v", groupArg, ErrNoGroupEntries) + } + user.Gid = gidArg + + // Must be inside valid gid range. + if user.Gid < minId || user.Gid > maxId { + return nil, ErrRange + } + + // Okay, so it's numeric. We can just roll with this. + } + } else if len(groups) > 0 { + // Supplementary group ids only make sense if in the implicit form. + user.Sgids = make([]int, len(groups)) + for i, group := range groups { + user.Sgids[i] = group.Gid + } + } + } + + return user, nil +} + +// GetAdditionalGroups looks up a list of groups by name or group id +// against the given /etc/group formatted data. If a group name cannot +// be found, an error will be returned. If a group id cannot be found, +// or the given group data is nil, the id will be returned as-is +// provided it is in the legal range. +func GetAdditionalGroups(additionalGroups []string, group io.Reader) ([]int, error) { + var groups = []Group{} + if group != nil { + var err error + groups, err = ParseGroupFilter(group, func(g Group) bool { + for _, ag := range additionalGroups { + if g.Name == ag || strconv.Itoa(g.Gid) == ag { + return true + } + } + return false + }) + if err != nil { + return nil, fmt.Errorf("Unable to find additional groups %v: %v", additionalGroups, err) + } + } + + gidMap := make(map[int]struct{}) + for _, ag := range additionalGroups { + var found bool + for _, g := range groups { + // if we found a matched group either by name or gid, take the + // first matched as correct + if g.Name == ag || strconv.Itoa(g.Gid) == ag { + if _, ok := gidMap[g.Gid]; !ok { + gidMap[g.Gid] = struct{}{} + found = true + break + } + } + } + // we asked for a group but didn't find it. let's check to see + // if we wanted a numeric group + if !found { + gid, err := strconv.Atoi(ag) + if err != nil { + return nil, fmt.Errorf("Unable to find group %s", ag) + } + // Ensure gid is inside gid range. + if gid < minId || gid > maxId { + return nil, ErrRange + } + gidMap[gid] = struct{}{} + } + } + gids := []int{} + for gid := range gidMap { + gids = append(gids, gid) + } + return gids, nil +} + +// GetAdditionalGroupsPath is a wrapper around GetAdditionalGroups +// that opens the groupPath given and gives it as an argument to +// GetAdditionalGroups. +func GetAdditionalGroupsPath(additionalGroups []string, groupPath string) ([]int, error) { + var group io.Reader + + if groupFile, err := os.Open(groupPath); err == nil { + group = groupFile + defer groupFile.Close() + } + return GetAdditionalGroups(additionalGroups, group) +} |