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#if defined(__linux__)
#define _DEFAULT_SOURCE
#endif
#include "hybbx/privilege.h"
#include "hybbx/config.h"
#include "hybbx/log.h"
#include "hybbx/types.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if !defined(_WIN32)
#include <errno.h>
#include <grp.h>
#include <pwd.h>
#include <sys/types.h>
#include <unistd.h>
#endif
#if !defined(_WIN32)
static int parse_optional_uid(const char *raw, uid_t *out)
{
char *end;
unsigned long value;
if (raw == NULL || raw[0] == '\0') {
return 0;
}
errno = 0;
value = strtoul(raw, &end, 10);
if (end == raw || *end != '\0' || errno != 0) {
return -1;
}
*out = (uid_t)value;
return 1;
}
static int parse_optional_gid(const char *raw, gid_t *out)
{
char *end;
unsigned long value;
if (raw == NULL || raw[0] == '\0') {
return 0;
}
errno = 0;
value = strtoul(raw, &end, 10);
if (end == raw || *end != '\0' || errno != 0) {
return -1;
}
*out = (gid_t)value;
return 1;
}
static hybbx_result_t resolve_target(
const hybbx_config_t *config,
uid_t *uid_out,
gid_t *gid_out,
char name_buf[64],
size_t name_buf_len)
{
const char *user_name;
const char *group_name;
const char *uid_raw;
const char *gid_raw;
struct passwd *pw = NULL;
struct group *gr = NULL;
uid_t uid_override = 0;
gid_t gid_override = 0;
int have_uid = 0;
int have_gid = 0;
user_name = hybbx_config_get(config, "service", "user", NULL);
group_name = hybbx_config_get(config, "service", "group", NULL);
uid_raw = hybbx_config_get(config, "service", "uid", NULL);
gid_raw = hybbx_config_get(config, "service", "gid", NULL);
have_uid = parse_optional_uid(uid_raw, &uid_override);
if (have_uid < 0) {
hybbx_log_warn("[service] invalid uid=%s", uid_raw);
return HYBBX_ERR_INVALID;
}
have_gid = parse_optional_gid(gid_raw, &gid_override);
if (have_gid < 0) {
hybbx_log_warn("[service] invalid gid=%s", gid_raw);
return HYBBX_ERR_INVALID;
}
if (user_name != NULL && user_name[0] != '\0') {
pw = getpwnam(user_name);
if (pw == NULL) {
hybbx_log_warn("[service] unknown user=%s", user_name);
return HYBBX_ERR_INVALID;
}
*uid_out = pw->pw_uid;
*gid_out = pw->pw_gid;
if (name_buf_len > 0) {
snprintf(name_buf, name_buf_len, "%s", pw->pw_name);
}
} else if (have_uid) {
pw = getpwuid(uid_override);
if (pw == NULL) {
hybbx_log_warn("[service] unknown uid=%s", uid_raw);
return HYBBX_ERR_INVALID;
}
*uid_out = pw->pw_uid;
*gid_out = pw->pw_gid;
if (name_buf_len > 0) {
snprintf(name_buf, name_buf_len, "%s", pw->pw_name);
}
} else {
return HYBBX_ERR_INVALID;
}
if (have_uid) {
*uid_out = uid_override;
}
if (group_name != NULL && group_name[0] != '\0') {
gr = getgrnam(group_name);
if (gr == NULL) {
hybbx_log_warn("[service] unknown group=%s", group_name);
return HYBBX_ERR_INVALID;
}
*gid_out = gr->gr_gid;
} else if (have_gid) {
if (getgrgid(gid_override) == NULL) {
hybbx_log_warn("[service] unknown gid=%s", gid_raw);
return HYBBX_ERR_INVALID;
}
*gid_out = gid_override;
}
return HYBBX_OK;
}
static hybbx_result_t drop_to(uid_t uid, gid_t gid, const char *name)
{
if (getuid() != 0) {
hybbx_log_warn("[service] privilege drop requires root start (euid=0)");
return HYBBX_ERR_DENIED;
}
if (name != NULL && name[0] != '\0') {
if (initgroups(name, gid) != 0) {
hybbx_log_warn("[service] initgroups(%s) failed: %s",
name, strerror(errno));
return HYBBX_ERR_IO;
}
}
if (setgid(gid) != 0) {
hybbx_log_warn("[service] setgid(%u) failed: %s",
(unsigned)gid, strerror(errno));
return HYBBX_ERR_IO;
}
if (setuid(uid) != 0) {
hybbx_log_warn("[service] setuid(%u) failed: %s",
(unsigned)uid, strerror(errno));
return HYBBX_ERR_IO;
}
if (setuid(0) == 0 || seteuid(0) == 0) {
hybbx_log_warn("[service] privilege drop incomplete — still root");
return HYBBX_ERR_IO;
}
hybbx_log_info("[service] dropped privileges to uid=%u gid=%u (%s)",
(unsigned)uid, (unsigned)gid,
name != NULL && name[0] != '\0' ? name : "?");
return HYBBX_OK;
}
#endif /* !_WIN32 */
hybbx_result_t hybbx_privilege_apply_from_config(const hybbx_config_t *config)
{
#if defined(_WIN32)
(void)config;
return HYBBX_OK;
#else
const char *user_name;
uid_t target_uid = 0;
gid_t target_gid = 0;
char resolved_name[64];
hybbx_result_t rc;
if (config == NULL) {
return HYBBX_ERR_INVALID;
}
resolved_name[0] = '\0';
user_name = hybbx_config_get(config, "service", "user", NULL);
if (geteuid() == 0) {
if ((user_name == NULL || user_name[0] == '\0') &&
hybbx_config_get(config, "service", "uid", NULL) == NULL) {
hybbx_log_warn(
"[service] refusing to run as root — set [service] user= "
"(and optional group=)");
return HYBBX_ERR_DENIED;
}
rc = resolve_target(config, &target_uid, &target_gid,
resolved_name, sizeof(resolved_name));
if (rc != HYBBX_OK) {
return rc;
}
return drop_to(target_uid, target_gid,
resolved_name[0] != '\0' ? resolved_name : user_name);
}
if (user_name != NULL && user_name[0] != '\0') {
struct passwd *pw = getpwnam(user_name);
if (pw == NULL) {
hybbx_log_warn("[service] unknown configured user=%s", user_name);
return HYBBX_OK;
}
if ((uid_t)geteuid() != pw->pw_uid) {
hybbx_log_warn(
"[service] running as uid=%u but [service] user=%s (uid=%u)",
(unsigned)geteuid(), user_name, (unsigned)pw->pw_uid);
}
}
return HYBBX_OK;
#endif
}
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