sway/sway/security.c
Mykyta Holubakha 7d8a84b587
Do not add empty policies
Policy allocation failure is non-fatal
2017-07-01 21:36:17 +03:00

229 lines
5.1 KiB
C

#define _XOPEN_SOURCE 700
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include "sway/config.h"
#include "sway/security.h"
#include "log.h"
static bool validate_ipc_target(const char *program) {
struct stat sb;
sway_log(L_DEBUG, "Validating IPC target '%s'", program);
if (!strcmp(program, "*")) {
return true;
}
if (lstat(program, &sb) == -1) {
return false;
}
if (!S_ISREG(sb.st_mode)) {
sway_log(L_ERROR,
"IPC target '%s' MUST be/point at an existing regular file",
program);
return false;
}
if (sb.st_uid != 0) {
#ifdef NDEBUG
sway_log(L_ERROR, "IPC target '%s' MUST be owned by root", program);
return false;
#else
sway_log(L_INFO, "IPC target '%s' MUST be owned by root (waived for debug build)", program);
return true;
#endif
}
if (sb.st_mode & S_IWOTH) {
sway_log(L_ERROR, "IPC target '%s' MUST NOT be world writable", program);
return false;
}
return true;
}
struct feature_policy *alloc_feature_policy(const char *program) {
uint32_t default_policy = 0;
if (!validate_ipc_target(program)) {
return NULL;
}
for (int i = 0; i < config->feature_policies->length; ++i) {
struct feature_policy *policy = config->feature_policies->items[i];
if (strcmp(policy->program, "*") == 0) {
default_policy = policy->features;
break;
}
}
struct feature_policy *policy = malloc(sizeof(struct feature_policy));
if (!policy) {
return NULL;
}
policy->program = strdup(program);
if (!policy->program) {
free(policy);
return NULL;
}
policy->features = default_policy;
return policy;
}
struct ipc_policy *alloc_ipc_policy(const char *program) {
uint32_t default_policy = 0;
if (!validate_ipc_target(program)) {
return NULL;
}
for (int i = 0; i < config->ipc_policies->length; ++i) {
struct ipc_policy *policy = config->ipc_policies->items[i];
if (strcmp(policy->program, "*") == 0) {
default_policy = policy->features;
break;
}
}
struct ipc_policy *policy = malloc(sizeof(struct ipc_policy));
if (!policy) {
return NULL;
}
policy->program = strdup(program);
if (!policy->program) {
free(policy);
return NULL;
}
policy->features = default_policy;
return policy;
}
struct command_policy *alloc_command_policy(const char *command) {
struct command_policy *policy = malloc(sizeof(struct command_policy));
if (!policy) {
return NULL;
}
policy->command = strdup(command);
if (!policy->command) {
free(policy);
return NULL;
}
policy->context = 0;
return policy;
}
static const char *get_pid_exe(pid_t pid) {
#ifdef __FreeBSD__
const char *fmt = "/proc/%d/file";
#else
const char *fmt = "/proc/%d/exe";
#endif
int pathlen = snprintf(NULL, 0, fmt, pid);
char *path = malloc(pathlen + 1);
if (path) {
snprintf(path, pathlen + 1, fmt, pid);
}
static char link[2048];
ssize_t len = !path ? -1 : readlink(path, link, sizeof(link));
if (len < 0) {
sway_log(L_INFO,
"WARNING: unable to read %s for security check. Using default policy.",
path);
strcpy(link, "*");
} else {
link[len] = '\0';
}
free(path);
return link;
}
struct feature_policy *get_feature_policy(const char *name) {
struct feature_policy *policy = NULL;
for (int i = 0; i < config->feature_policies->length; ++i) {
struct feature_policy *p = config->feature_policies->items[i];
if (strcmp(p->program, name) == 0) {
policy = p;
break;
}
}
if (!policy) {
policy = alloc_feature_policy(name);
sway_assert(policy, "Unable to allocate security policy");
if (policy) {
list_add(config->feature_policies, policy);
}
}
return policy;
}
uint32_t get_feature_policy_mask(pid_t pid) {
uint32_t default_policy = 0;
const char *link = get_pid_exe(pid);
for (int i = 0; i < config->feature_policies->length; ++i) {
struct feature_policy *policy = config->feature_policies->items[i];
if (strcmp(policy->program, "*") == 0) {
default_policy = policy->features;
}
if (strcmp(policy->program, link) == 0) {
return policy->features;
}
}
return default_policy;
}
uint32_t get_ipc_policy_mask(pid_t pid) {
uint32_t default_policy = 0;
const char *link = get_pid_exe(pid);
for (int i = 0; i < config->ipc_policies->length; ++i) {
struct ipc_policy *policy = config->ipc_policies->items[i];
if (strcmp(policy->program, "*") == 0) {
default_policy = policy->features;
}
if (strcmp(policy->program, link) == 0) {
return policy->features;
}
}
return default_policy;
}
uint32_t get_command_policy_mask(const char *cmd) {
uint32_t default_policy = 0;
for (int i = 0; i < config->command_policies->length; ++i) {
struct command_policy *policy = config->command_policies->items[i];
if (strcmp(policy->command, "*") == 0) {
default_policy = policy->context;
}
if (strcmp(policy->command, cmd) == 0) {
return policy->context;
}
}
return default_policy;
}
const char *command_policy_str(enum command_context context) {
switch (context) {
case CONTEXT_ALL:
return "all";
case CONTEXT_CONFIG:
return "config";
case CONTEXT_BINDING:
return "binding";
case CONTEXT_IPC:
return "IPC";
case CONTEXT_CRITERIA:
return "criteria";
default:
return "unknown";
}
}