X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Flabel.c;h=b6af38d82d39a0940c6133c4ca886d7384c59cdb;hp=dce6f45c80a83a0ebb87872b20c822cbccb22dcf;hb=493d521d9ffe706741665a88ea14929913ea2eaf;hpb=5430f7f2bc7330f3088b894166bf3524a067e3d8 diff --git a/src/shared/label.c b/src/shared/label.c index dce6f45c8..b6af38d82 100644 --- a/src/shared/label.c +++ b/src/shared/label.c @@ -20,38 +20,79 @@ ***/ #include -#include #include #include #include #include +#include +#include +#include +#include +#ifdef HAVE_SELINUX +#include +#include +#include +#endif #include "label.h" +#include "strv.h" #include "util.h" +#include "path-util.h" +#include "selinux-util.h" +#include "smack-util.h" #ifdef HAVE_SELINUX -#include -#include +DEFINE_TRIVIAL_CLEANUP_FUNC(security_context_t, freecon); +DEFINE_TRIVIAL_CLEANUP_FUNC(context_t, context_free); -static struct selabel_handle *label_hnd = NULL; +#define _cleanup_security_context_free_ _cleanup_(freeconp) +#define _cleanup_context_free_ _cleanup_(context_freep) -static int use_selinux_cached = -1; +static struct selabel_handle *label_hnd = NULL; +#endif -static inline bool use_selinux(void) { +static int smack_relabel_in_dev(const char *path) { + int r = 0; - if (use_selinux_cached < 0) - use_selinux_cached = is_selinux_enabled() > 0; +#ifdef HAVE_SMACK + struct stat sb; + const char *label; - return use_selinux_cached; -} + /* + * Path must be in /dev and must exist + */ + if (!path_startswith(path, "/dev")) + return 0; -void label_retest_selinux(void) { - use_selinux_cached = -1; -} + r = lstat(path, &sb); + if (r < 0) + return -errno; + + /* + * Label directories and character devices "*". + * Label symlinks "_". + * Don't change anything else. + */ + if (S_ISDIR(sb.st_mode)) + label = SMACK_STAR_LABEL; + else if (S_ISLNK(sb.st_mode)) + label = SMACK_FLOOR_LABEL; + else if (S_ISCHR(sb.st_mode)) + label = SMACK_STAR_LABEL; + else + return 0; + r = setxattr(path, "security.SMACK64", label, strlen(label), 0); + if (r < 0) { + log_error("Smack relabeling \"%s\" %m", path); + return -errno; + } #endif -int label_init(void) { + return r; +} + +int label_init(const char *prefix) { int r = 0; #ifdef HAVE_SELINUX @@ -67,7 +108,15 @@ int label_init(void) { before_mallinfo = mallinfo(); before_timestamp = now(CLOCK_MONOTONIC); - label_hnd = selabel_open(SELABEL_CTX_FILE, NULL, 0); + if (prefix) { + struct selinux_opt options[] = { + { .type = SELABEL_OPT_SUBSET, .value = prefix }, + }; + + label_hnd = selabel_open(SELABEL_CTX_FILE, options, ELEMENTSOF(options)); + } else + label_hnd = selabel_open(SELABEL_CTX_FILE, NULL, 0); + if (!label_hnd) { log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG, "Failed to initialize SELinux context: %m"); @@ -81,23 +130,23 @@ int label_init(void) { l = after_mallinfo.uordblks > before_mallinfo.uordblks ? after_mallinfo.uordblks - before_mallinfo.uordblks : 0; - log_info("Successfully loaded SELinux database in %s, size on heap is %iK.", - format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp), - (l+1023)/1024); + log_debug("Successfully loaded SELinux database in %s, size on heap is %iK.", + format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp, 0), + (l+1023)/1024); } #endif return r; } -int label_fix(const char *path, bool ignore_enoent) { +static int label_fix_selinux(const char *path, bool ignore_enoent, bool ignore_erofs) { int r = 0; #ifdef HAVE_SELINUX struct stat st; security_context_t fcon; - if (!use_selinux() || !label_hnd) + if (!label_hnd) return 0; r = lstat(path, &st); @@ -123,6 +172,9 @@ int label_fix(const char *path, bool ignore_enoent) { if (ignore_enoent && errno == ENOENT) return 0; + if (ignore_erofs && errno == EROFS) + return 0; + log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG, "Unable to fix label of %s: %m", path); r = security_getenforce() == 1 ? -errno : 0; @@ -132,10 +184,31 @@ int label_fix(const char *path, bool ignore_enoent) { return r; } +int label_fix(const char *path, bool ignore_enoent, bool ignore_erofs) { + int r = 0; + + if (use_selinux()) { + r = label_fix_selinux(path, ignore_enoent, ignore_erofs); + if (r < 0) + return r; + } + + if (use_smack()) { + r = smack_relabel_in_dev(path); + if (r < 0) + return r; + } + + return r; +} + void label_finish(void) { #ifdef HAVE_SELINUX - if (use_selinux() && label_hnd) + if (!use_selinux()) + return; + + if (label_hnd) selabel_close(label_hnd); #endif } @@ -177,36 +250,114 @@ fail: return r; } -int label_fifofile_set(const char *path) { - int r = 0; +int label_get_our_label(char **label) { + int r = -EOPNOTSUPP; #ifdef HAVE_SELINUX - security_context_t filecon = NULL; + char *l = NULL; - if (!use_selinux() || !label_hnd) - return 0; - - r = selabel_lookup_raw(label_hnd, &filecon, path, S_IFIFO); + r = getcon(&l); if (r < 0) - r = -errno; - else if (r == 0) { - r = setfscreatecon(filecon); + return r; + + *label = l; +#endif + + return r; +} + +int label_get_child_mls_label(int socket_fd, const char *exe, char **label) { + int r = -EOPNOTSUPP; + +#ifdef HAVE_SELINUX + + _cleanup_security_context_free_ security_context_t mycon = NULL, peercon = NULL, fcon = NULL, ret = NULL; + _cleanup_context_free_ context_t pcon = NULL, bcon = NULL; + security_class_t sclass; + + const char *range = NULL; + + assert(socket_fd >= 0); + assert(exe); + assert(label); + + r = getcon(&mycon); + if (r < 0) { + r = -EINVAL; + goto out; + } + + r = getpeercon(socket_fd, &peercon); + if (r < 0) { + r = -EINVAL; + goto out; + } + + r = getexeccon(&fcon); + if (r < 0) { + r = -EINVAL; + goto out; + } + + if (!fcon) { + /* If there is no context set for next exec let's use context + of target executable */ + r = getfilecon(exe, &fcon); if (r < 0) { - log_error("Failed to set SELinux file context on %s: %m", path); r = -errno; + goto out; } + } - freecon(filecon); + bcon = context_new(mycon); + if (!bcon) { + r = -ENOMEM; + goto out; } - if (r < 0 && security_getenforce() == 0) - r = 0; -#endif + pcon = context_new(peercon); + if (!pcon) { + r = -ENOMEM; + goto out; + } + range = context_range_get(pcon); + if (!range) { + r = -errno; + goto out; + } + + r = context_range_set(bcon, range); + if (r) { + r = -errno; + goto out; + } + + freecon(mycon); + mycon = context_str(bcon); + if (!mycon) { + r = -errno; + goto out; + } + + sclass = string_to_security_class("process"); + r = security_compute_create(mycon, fcon, sclass, &ret); + if (r < 0) { + r = -EINVAL; + goto out; + } + + *label = ret; + r = 0; + +out: + if (r < 0 && security_getenforce() == 1) + return r; +#endif return r; } -int label_symlinkfile_set(const char *path) { +int label_context_set(const char *path, mode_t mode) { int r = 0; #ifdef HAVE_SELINUX @@ -215,8 +366,8 @@ int label_symlinkfile_set(const char *path) { if (!use_selinux() || !label_hnd) return 0; - r = selabel_lookup_raw(label_hnd, &filecon, path, S_IFLNK); - if (r < 0) + r = selabel_lookup_raw(label_hnd, &filecon, path, mode); + if (r < 0 && errno != ENOENT) r = -errno; else if (r == 0) { r = setfscreatecon(filecon); @@ -253,9 +404,11 @@ int label_socket_set(const char *label) { return 0; } -void label_file_clear(void) { +void label_context_clear(void) { #ifdef HAVE_SELINUX + PROTECT_ERRNO; + if (!use_selinux()) return; @@ -266,6 +419,8 @@ void label_file_clear(void) { void label_socket_clear(void) { #ifdef HAVE_SELINUX + PROTECT_ERRNO; + if (!use_selinux()) return; @@ -283,28 +438,26 @@ void label_free(const char *label) { #endif } -int label_mkdir(const char *path, mode_t mode) { - - /* Creates a directory and labels it according to the SELinux policy */ +static int label_mkdir_selinux(const char *path, mode_t mode) { + int r = 0; #ifdef HAVE_SELINUX - int r; + /* Creates a directory and labels it according to the SELinux policy */ security_context_t fcon = NULL; - if (!use_selinux() || !label_hnd) - goto skipped; + if (!label_hnd) + return 0; if (path_is_absolute(path)) r = selabel_lookup_raw(label_hnd, &fcon, path, S_IFDIR); else { - char *newpath; + _cleanup_free_ char *newpath; newpath = path_make_absolute_cwd(path); if (!newpath) return -ENOMEM; r = selabel_lookup_raw(label_hnd, &fcon, newpath, S_IFDIR); - free(newpath); } if (r == 0) @@ -326,12 +479,35 @@ int label_mkdir(const char *path, mode_t mode) { finish: setfscreatecon(NULL); freecon(fcon); +#endif return r; +} -skipped: -#endif - return mkdir(path, mode) < 0 ? -errno : 0; +int label_mkdir(const char *path, mode_t mode) { + int r; + + if (use_selinux()) { + r = label_mkdir_selinux(path, mode); + if (r < 0) + return r; + } + + if (use_smack()) { + r = mkdir(path, mode); + if (r < 0 && errno != EEXIST) + return -errno; + + r = smack_relabel_in_dev(path); + if (r < 0) + return r; + } + + r = mkdir(path, mode); + if (r < 0 && errno != EEXIST) + return -errno; + + return 0; } int label_bind(int fd, const struct sockaddr *addr, socklen_t addrlen) { @@ -339,10 +515,10 @@ int label_bind(int fd, const struct sockaddr *addr, socklen_t addrlen) { /* Binds a socket and label its file system object according to the SELinux policy */ #ifdef HAVE_SELINUX - int r; security_context_t fcon = NULL; const struct sockaddr_un *un; - char *path = NULL; + char *path; + int r; assert(fd >= 0); assert(addr); @@ -364,24 +540,18 @@ int label_bind(int fd, const struct sockaddr *addr, socklen_t addrlen) { if (un->sun_path[0] == 0) goto skipped; - path = strndup(un->sun_path, addrlen - offsetof(struct sockaddr_un, sun_path)); - if (!path) - return -ENOMEM; + path = strndupa(un->sun_path, addrlen - offsetof(struct sockaddr_un, sun_path)); if (path_is_absolute(path)) r = selabel_lookup_raw(label_hnd, &fcon, path, S_IFSOCK); else { - char *newpath; + _cleanup_free_ char *newpath; newpath = path_make_absolute_cwd(path); - - if (!newpath) { - free(path); + if (!newpath) return -ENOMEM; - } r = selabel_lookup_raw(label_hnd, &fcon, newpath, S_IFSOCK); - free(newpath); } if (r == 0) @@ -403,7 +573,6 @@ int label_bind(int fd, const struct sockaddr *addr, socklen_t addrlen) { finish: setfscreatecon(NULL); freecon(fcon); - free(path); return r; @@ -411,3 +580,15 @@ skipped: #endif return bind(fd, addr, addrlen) < 0 ? -errno : 0; } + +int label_apply(const char *path, const char *label) { + int r = 0; + +#ifdef HAVE_SELINUX + if (!use_selinux()) + return 0; + + r = setfilecon(path, (char *)label); +#endif + return r; +}