diff options
Diffstat (limited to 'samples/landlock')
| -rw-r--r-- | samples/landlock/sandboxer.c | 96 |
1 files changed, 52 insertions, 44 deletions
diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c index 5ce961b5bda7..c089e9cdaf32 100644 --- a/samples/landlock/sandboxer.c +++ b/samples/landlock/sandboxer.c @@ -22,9 +22,9 @@ #include <unistd.h> #ifndef landlock_create_ruleset -static inline int landlock_create_ruleset( - const struct landlock_ruleset_attr *const attr, - const size_t size, const __u32 flags) +static inline int +landlock_create_ruleset(const struct landlock_ruleset_attr *const attr, + const size_t size, const __u32 flags) { return syscall(__NR_landlock_create_ruleset, attr, size, flags); } @@ -32,17 +32,18 @@ static inline int landlock_create_ruleset( #ifndef landlock_add_rule static inline int landlock_add_rule(const int ruleset_fd, - const enum landlock_rule_type rule_type, - const void *const rule_attr, const __u32 flags) + const enum landlock_rule_type rule_type, + const void *const rule_attr, + const __u32 flags) { - return syscall(__NR_landlock_add_rule, ruleset_fd, rule_type, - rule_attr, flags); + return syscall(__NR_landlock_add_rule, ruleset_fd, rule_type, rule_attr, + flags); } #endif #ifndef landlock_restrict_self static inline int landlock_restrict_self(const int ruleset_fd, - const __u32 flags) + const __u32 flags) { return syscall(__NR_landlock_restrict_self, ruleset_fd, flags); } @@ -79,9 +80,8 @@ static int parse_path(char *env_path, const char ***const path_list) /* clang-format on */ -static int populate_ruleset( - const char *const env_var, const int ruleset_fd, - const __u64 allowed_access) +static int populate_ruleset(const char *const env_var, const int ruleset_fd, + const __u64 allowed_access) { int num_paths, i, ret = 1; char *env_path_name; @@ -111,12 +111,10 @@ static int populate_ruleset( for (i = 0; i < num_paths; i++) { struct stat statbuf; - path_beneath.parent_fd = open(path_list[i], O_PATH | - O_CLOEXEC); + path_beneath.parent_fd = open(path_list[i], O_PATH | O_CLOEXEC); if (path_beneath.parent_fd < 0) { fprintf(stderr, "Failed to open \"%s\": %s\n", - path_list[i], - strerror(errno)); + path_list[i], strerror(errno)); goto out_free_name; } if (fstat(path_beneath.parent_fd, &statbuf)) { @@ -127,9 +125,10 @@ static int populate_ruleset( if (!S_ISDIR(statbuf.st_mode)) path_beneath.allowed_access &= ACCESS_FILE; if (landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH, - &path_beneath, 0)) { - fprintf(stderr, "Failed to update the ruleset with \"%s\": %s\n", - path_list[i], strerror(errno)); + &path_beneath, 0)) { + fprintf(stderr, + "Failed to update the ruleset with \"%s\": %s\n", + path_list[i], strerror(errno)); close(path_beneath.parent_fd); goto out_free_name; } @@ -171,55 +170,64 @@ int main(const int argc, char *const argv[], char *const *const envp) int ruleset_fd; struct landlock_ruleset_attr ruleset_attr = { .handled_access_fs = ACCESS_FS_ROUGHLY_READ | - ACCESS_FS_ROUGHLY_WRITE, + ACCESS_FS_ROUGHLY_WRITE, }; if (argc < 2) { - fprintf(stderr, "usage: %s=\"...\" %s=\"...\" %s <cmd> [args]...\n\n", - ENV_FS_RO_NAME, ENV_FS_RW_NAME, argv[0]); - fprintf(stderr, "Launch a command in a restricted environment.\n\n"); + fprintf(stderr, + "usage: %s=\"...\" %s=\"...\" %s <cmd> [args]...\n\n", + ENV_FS_RO_NAME, ENV_FS_RW_NAME, argv[0]); + fprintf(stderr, + "Launch a command in a restricted environment.\n\n"); fprintf(stderr, "Environment variables containing paths, " "each separated by a colon:\n"); - fprintf(stderr, "* %s: list of paths allowed to be used in a read-only way.\n", - ENV_FS_RO_NAME); - fprintf(stderr, "* %s: list of paths allowed to be used in a read-write way.\n", - ENV_FS_RW_NAME); - fprintf(stderr, "\nexample:\n" - "%s=\"/bin:/lib:/usr:/proc:/etc:/dev/urandom\" " - "%s=\"/dev/null:/dev/full:/dev/zero:/dev/pts:/tmp\" " - "%s bash -i\n", - ENV_FS_RO_NAME, ENV_FS_RW_NAME, argv[0]); + fprintf(stderr, + "* %s: list of paths allowed to be used in a read-only way.\n", + ENV_FS_RO_NAME); + fprintf(stderr, + "* %s: list of paths allowed to be used in a read-write way.\n", + ENV_FS_RW_NAME); + fprintf(stderr, + "\nexample:\n" + "%s=\"/bin:/lib:/usr:/proc:/etc:/dev/urandom\" " + "%s=\"/dev/null:/dev/full:/dev/zero:/dev/pts:/tmp\" " + "%s bash -i\n", + ENV_FS_RO_NAME, ENV_FS_RW_NAME, argv[0]); return 1; } - ruleset_fd = landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); + ruleset_fd = + landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); if (ruleset_fd < 0) { const int err = errno; perror("Failed to create a ruleset"); switch (err) { case ENOSYS: - fprintf(stderr, "Hint: Landlock is not supported by the current kernel. " - "To support it, build the kernel with " - "CONFIG_SECURITY_LANDLOCK=y and prepend " - "\"landlock,\" to the content of CONFIG_LSM.\n"); + fprintf(stderr, + "Hint: Landlock is not supported by the current kernel. " + "To support it, build the kernel with " + "CONFIG_SECURITY_LANDLOCK=y and prepend " + "\"landlock,\" to the content of CONFIG_LSM.\n"); break; case EOPNOTSUPP: - fprintf(stderr, "Hint: Landlock is currently disabled. " - "It can be enabled in the kernel configuration by " - "prepending \"landlock,\" to the content of CONFIG_LSM, " - "or at boot time by setting the same content to the " - "\"lsm\" kernel parameter.\n"); + fprintf(stderr, + "Hint: Landlock is currently disabled. " + "It can be enabled in the kernel configuration by " + "prepending \"landlock,\" to the content of CONFIG_LSM, " + "or at boot time by setting the same content to the " + "\"lsm\" kernel parameter.\n"); break; } return 1; } if (populate_ruleset(ENV_FS_RO_NAME, ruleset_fd, - ACCESS_FS_ROUGHLY_READ)) { + ACCESS_FS_ROUGHLY_READ)) { goto err_close_ruleset; } if (populate_ruleset(ENV_FS_RW_NAME, ruleset_fd, - ACCESS_FS_ROUGHLY_READ | ACCESS_FS_ROUGHLY_WRITE)) { + ACCESS_FS_ROUGHLY_READ | + ACCESS_FS_ROUGHLY_WRITE)) { goto err_close_ruleset; } if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { @@ -236,7 +244,7 @@ int main(const int argc, char *const argv[], char *const *const envp) cmd_argv = argv + 1; execvpe(cmd_path, cmd_argv, envp); fprintf(stderr, "Failed to execute \"%s\": %s\n", cmd_path, - strerror(errno)); + strerror(errno)); fprintf(stderr, "Hint: access to the binary, the interpreter or " "shared libraries may be denied.\n"); return 1; |