diff --git a/libselinux/Makefile b/libselinux/Makefile index fd4f0b1..51469bc 100644 --- a/libselinux/Makefile +++ b/libselinux/Makefile @@ -1,4 +1,4 @@ -SUBDIRS = src include utils man +SUBDIRS = src include utils man golang DISABLE_AVC ?= n DISABLE_SETRANS ?= n diff --git a/libselinux/golang/Makefile b/libselinux/golang/Makefile new file mode 100644 index 0000000..a5f0692 --- /dev/null +++ b/libselinux/golang/Makefile @@ -0,0 +1,17 @@ +# Installation directories. +PREFIX ?= $(DESTDIR)/usr +GODIR ?= $(PREFIX)/share/gocode/selinux + +all: + +install: + [ -d $(GODIR) ] || mkdir -p $(GODIR) + install -m 644 selinux.go $(GODIR) + +test: + +clean: + +indent: + +relabel: diff --git a/libselinux/golang/selinux.go b/libselinux/golang/selinux.go new file mode 100644 index 0000000..018c955 --- /dev/null +++ b/libselinux/golang/selinux.go @@ -0,0 +1,282 @@ +package selinux + +/* + The selinux package is a go bindings to libselinux required to add selinux + support to docker. + + Author Dan Walsh + + Used some ideas/code from the go-ini packages https://github.com/vaughan0 + By Vaughan Newton +*/ + +// #cgo pkg-config: libselinux +// #include +// #include +import "C" +import ( + "encoding/binary" + "crypto/rand" + "unsafe" + "fmt" + "bufio" + "regexp" + "io" + "os" + "strings" +) + +var ( + assignRegex = regexp.MustCompile(`^([^=]+)=(.*)$`) + mcs_list = make(map[string]bool) +) + +func Matchpathcon(path string, mode int) (string, error) { + var con C.security_context_t + var scon string + rc, err := C.matchpathcon(C.CString(path),C.mode_t(mode), &con) + if rc == 0 { + scon = C.GoString(con) + C.free(unsafe.Pointer(con)) + } + return scon, err +} + +func Setfilecon(path,scon string) (int, error) { + rc, err := C.lsetfilecon(C.CString(path),C.CString(scon)) + return int(rc), err +} + +func Setexeccon(scon string) (int, error) { + var val *C.char + if ! Selinux_enabled() { + return 0, nil + } + if scon != "" { + val = C.CString(scon) + } else { + val = nil + } + rc, err := C.setexeccon(val) + return int(rc), err +} + +type Context struct { + con []string +} +func (c *Context) Set_user(user string) { + c.con[0]=user +} +func (c *Context) Get_user() string { + return c.con[0] +} +func (c *Context) Set_role(role string) { + c.con[1]=role +} +func (c *Context) Get_role() string { + return c.con[1] +} +func (c *Context) Set_type(setype string) { + c.con[2]=setype +} +func (c *Context) Get_type() string { + return c.con[2] +} +func (c *Context) Set_level(mls string) { + c.con[3]=mls +} +func (c *Context) Get_level() string { + return c.con[3] +} +func (c *Context) Get() string{ + return strings.Join(c.con,":") +} +func (c *Context) Set(scon string) { + c.con = strings.SplitN(scon,":",4) +} +func New_context(scon string) Context { + var con Context + con.Set(scon) + return con +} + +func Is_selinux_enabled() bool { + b := C.is_selinux_enabled() + if b > 0 { + return true; + } + return false +} + +func Selinux_enabled() bool { + b := C.is_selinux_enabled() + if b > 0 { + return true; + } + return false +} + +const ( + Enforcing = 1 + Permissive = 0 + Disabled = -1 +) + +func Selinux_getenforce() int { + return int(C.security_getenforce()) +} + +func Selinux_getenforcemode() (int) { + var enforce C.int + C.selinux_getenforcemode(&enforce) + return int(enforce) +} + +func mcs_add(mcs string) { + mcs_list[mcs] = true +} + +func mcs_delete(mcs string) { + mcs_list[mcs] = false +} + +func mcs_exists(mcs string) bool { + return mcs_list[mcs] +} + +func uniq_mcs(catRange uint32) string { + var n uint32 + var c1,c2 uint32 + var mcs string + for ;; { + binary.Read(rand.Reader, binary.LittleEndian, &n) + c1 = n % catRange + binary.Read(rand.Reader, binary.LittleEndian, &n) + c2 = n % catRange + if c1 == c2 { + continue + } else { + if c1 > c2 { + t := c1 + c1 = c2 + c2 = t + } + } + mcs = fmt.Sprintf("s0:c%d,c%d", c1, c2) + if mcs_exists(mcs) { + continue + } + mcs_add(mcs) + break + } + return mcs +} +func free_context(process_label string) { + var scon Context + scon = New_context(process_label) + mcs_delete(scon.Get_level()) +} + +func Get_lxc_contexts() (process_label string, file_label string) { + var val, key string + var bufin *bufio.Reader + if ! Selinux_enabled() { + return + } + lxc_path := C.GoString(C.selinux_lxc_contexts_path()) + file_label = "system_u:object_r:svirt_sandbox_file_t:s0" + process_label = "system_u:system_r:svirt_lxc_net_t:s0" + + in, err := os.Open(lxc_path) + if err != nil { + goto exit + } + + defer in.Close() + bufin = bufio.NewReader(in) + + for done := false; !done; { + var line string + if line, err = bufin.ReadString('\n'); err != nil { + if err == io.EOF { + done = true + } else { + goto exit + } + } + line = strings.TrimSpace(line) + if len(line) == 0 { + // Skip blank lines + continue + } + if line[0] == ';' || line[0] == '#' { + // Skip comments + continue + } + if groups := assignRegex.FindStringSubmatch(line); groups != nil { + key, val = strings.TrimSpace(groups[1]), strings.TrimSpace(groups[2]) + if key == "process" { + process_label = strings.Trim(val,"\"") + } + if key == "file" { + file_label = strings.Trim(val,"\"") + } + } + } +exit: + var scon Context + mcs := uniq_mcs(1024) + scon = New_context(process_label) + scon.Set_level(mcs) + process_label = scon.Get() + scon = New_context(file_label) + scon.Set_level(mcs) + file_label = scon.Get() + return process_label, file_label +} + +func CopyLevel (src, dest string) (string, error) { + if ! Selinux_enabled() { + return "", nil + } + if src == "" { + return "", nil + } + rc, err := C.security_check_context(C.CString(src)) + if rc != 0 { + return "", err + } + rc, err = C.security_check_context(C.CString(dest)) + if rc != 0 { + return "", err + } + scon := New_context(src) + tcon := New_context(dest) + tcon.Set_level(scon.Get_level()) + return tcon.Get(), nil +} + +func Test() { + var plabel,flabel string + if ! Selinux_enabled() { + return + } + + plabel, flabel = Get_lxc_contexts() + fmt.Println(plabel) + fmt.Println(flabel) + free_context(plabel) + plabel, flabel = Get_lxc_contexts() + fmt.Println(plabel) + fmt.Println(flabel) + free_context(plabel) + if Selinux_enabled() { + fmt.Println("Enabled") + } else { + fmt.Println("Disabled") + } + fmt.Println(Selinux_getenforce()) + fmt.Println(Selinux_getenforcemode()) + flabel,_ = Matchpathcon("/home/dwalsh/.emacs", 0) + fmt.Println(flabel) +} diff --git a/libselinux/src/Makefile b/libselinux/src/Makefile index 02dd829..6dfdb46 100644 --- a/libselinux/src/Makefile +++ b/libselinux/src/Makefile @@ -114,7 +114,7 @@ $(LIBA): $(OBJS) $(RANLIB) $@ $(LIBSO): $(LOBJS) - $(CC) $(CFLAGS) -shared -o $@ $^ -lpcre -ldl $(LDFLAGS) -L$(LIBDIR) -Wl,-soname,$(LIBSO),-z,defs,-z,relro + $(CC) $(CFLAGS) -shared -o $@ $^ -lpcre -llzma -ldl $(LDFLAGS) -L$(LIBDIR) -Wl,-soname,$(LIBSO),-z,defs,-z,relro ln -sf $@ $(TARGET) $(LIBPC): $(LIBPC).in ../VERSION diff --git a/libselinux/src/load_policy.c b/libselinux/src/load_policy.c index e419f1a..fdeca93 100644 --- a/libselinux/src/load_policy.c +++ b/libselinux/src/load_policy.c @@ -16,6 +16,82 @@ #include #include "policy.h" #include +#include + +static char *lzmaread(int fd, size_t *rsize) { + int capacity = 64*1024; + char *buf = NULL; + int tmpsize = 8 * 1024; + unsigned char tmp[tmpsize]; + unsigned char tmp_out[tmpsize]; + size_t size = 0; + lzma_stream strm = LZMA_STREAM_INIT; + lzma_action action = LZMA_RUN; + lzma_ret ret; + + FILE *stream = fdopen (fd, "r"); + if (!stream) { + return NULL; + } + ret = lzma_stream_decoder(&strm, UINT64_MAX, + LZMA_CONCATENATED); + + strm.avail_in = 0; + strm.next_out = tmp_out; + strm.avail_out = tmpsize; + + buf = (char *) malloc (capacity); + if (!buf) + goto err; + + while (1) { + if (strm.avail_in == 0) { + strm.next_in = tmp; + strm.avail_in = fread(tmp, 1, tmpsize, stream); + + if (ferror(stream)) { + // POSIX says that fread() sets errno if + // an error occurred. ferror() doesn't + // touch errno. + goto err; + } + if (feof(stream)) action = LZMA_FINISH; + } + + ret = lzma_code(&strm, action); + + // Write and check write error before checking decoder error. + // This way as much data as possible gets written to output + // even if decoder detected an error. + if (strm.avail_out == 0 || ret != LZMA_OK) { + const size_t num = tmpsize - strm.avail_out; + if (num > capacity) { + buf = (char*) realloc (buf, size*2); + capacity = size; + } + memcpy (buf+size, tmp_out, num); + capacity -= num; + size += num; + strm.next_out = tmp_out; + strm.avail_out = tmpsize; + } + if (ret != LZMA_OK) { + if (ret == LZMA_STREAM_END) { + break; + } else { + goto err; + } + } + } + *rsize = size; + + goto exit; +err: + free(buf); buf = NULL; +exit: + lzma_end(&strm); + return buf; +} int security_load_policy(void *data, size_t len) { @@ -55,7 +131,7 @@ int selinux_mkload_policy(int preservebools) struct stat sb; struct utsname uts; size_t size; - void *map, *data; + void *map = NULL, *data=NULL; int fd, rc = -1, prot; sepol_policydb_t *policydb; sepol_policy_file_t *pf; @@ -181,24 +257,28 @@ checkbool: goto dlclose; } - if (fstat(fd, &sb) < 0) { - fprintf(stderr, - "SELinux: Could not stat policy file %s: %s\n", - path, strerror(errno)); - goto close; - } - - prot = PROT_READ; - if (setlocaldefs || preservebools) - prot |= PROT_WRITE; + data = lzmaread(fd,&size); - size = sb.st_size; - data = map = mmap(NULL, size, prot, MAP_PRIVATE, fd, 0); - if (map == MAP_FAILED) { - fprintf(stderr, - "SELinux: Could not map policy file %s: %s\n", + if (!data) { + if (fstat(fd, &sb) < 0) { + fprintf(stderr, + "SELinux: Could not stat policy file %s: %s\n", path, strerror(errno)); - goto close; + goto close; + } + + prot = PROT_READ; + if (setlocaldefs || preservebools) + prot |= PROT_WRITE; + + size = sb.st_size; + data = map = mmap(NULL, size, prot, MAP_PRIVATE, fd, 0); + if (map == MAP_FAILED) { + fprintf(stderr, + "SELinux: Could not map policy file %s: %s\n", + path, strerror(errno)); + goto close; + } } if (vers > kernvers && usesepol) { @@ -210,6 +290,8 @@ checkbool: goto unmap; } policy_file_set_mem(pf, data, size); + if (!map) + free(data); if (policydb_read(policydb, pf)) { policy_file_free(pf); policydb_free(policydb); @@ -223,7 +305,8 @@ checkbool: path); policy_file_free(pf); policydb_free(policydb); - munmap(map, sb.st_size); + if (map) + munmap(map, sb.st_size); close(fd); vers--; goto search; @@ -275,7 +358,7 @@ checkbool: #endif } - + rc = security_load_policy(data, size); if (rc) @@ -286,7 +369,8 @@ checkbool: unmap: if (data != map) free(data); - munmap(map, sb.st_size); + if (map) + munmap(map, sb.st_size); close: close(fd); dlclose: @@ -410,7 +494,7 @@ int selinux_init_load_policy(int *enforce) * already mounted and selinuxmnt set above. */ - if (seconfig == -1) { + if (*enforce == -1) { /* Runtime disable of SELinux. */ rc = security_disable(); if (rc == 0) { diff --git a/libselinux/src/matchpathcon.c b/libselinux/src/matchpathcon.c index 2d7369e..2a00807 100644 --- a/libselinux/src/matchpathcon.c +++ b/libselinux/src/matchpathcon.c @@ -2,6 +2,7 @@ #include #include #include +#include #include "selinux_internal.h" #include "label_internal.h" #include "callbacks.h" @@ -62,7 +63,7 @@ static void { va_list ap; va_start(ap, fmt); - vfprintf(stderr, fmt, ap); + vsyslog(LOG_ERR, fmt, ap); va_end(ap); }