system-plugin.c

#include <assert.h>
#include <stdio.h>
#include <syslog.h>
#include <string.h>
#include <sysrepo.h>
#include <unistd.h>
#include <sys/utsname.h>
#include <time.h>

// Next:
// ? Timezone
// X NTP (software specific)
// X DNS (software specific)
// X RADIUS (software specific)
//   Local users
//   Set datetime RPC
//   Restart and shutdown RPCs (done)

static void
retrieve_current_config(sr_session_ctx_t *session)
{
    sr_val_t *value = NULL;
    int rc = SR_ERR_OK;

	const char *hostname;

    rc = sr_get_item(session, "/ietf-system:system/hostname", &value);
    if (SR_ERR_NOT_FOUND == rc) {
		hostname = "default";
    } else if (SR_ERR_OK != rc) {
        syslog(LOG_DEBUG, "error by retrieving configuration: %s", sr_strerror(rc));
		return;
    } else {
		assert(value->type == SR_STRING_T);
		hostname = value->data.string_val;
    }

    syslog(LOG_DEBUG, "Setting hostname to %s\n", hostname);
    sethostname(hostname, strlen(hostname));

    if (SR_ERR_OK != rc) {
        sr_free_val(value);
    }
}

static int
module_change_cb(sr_session_ctx_t *session, const char *module_name, sr_notif_event_t event, void *private_ctx)
{
    syslog(LOG_DEBUG, "configuration has changed. Event=%s", event==SR_EV_APPLY?"apply":event==SR_EV_VERIFY?"verify":"unknown");

    retrieve_current_config(session);

    return SR_ERR_OK;
}

#define TIME_BUF_SIZE 64
static char boottime[TIME_BUF_SIZE];

static void get_time_as_string(char (*out)[TIME_BUF_SIZE])
{
	time_t curtime = time(NULL);
	strftime(*out, sizeof(*out), "%Y-%m-%dT%H:%M:%S%z", localtime(&curtime));
	// timebuf ends in +hhmm but should be +hh:mm
	memmove(*out+strlen(*out)-1, *out+strlen(*out)-2, 3);
	(*out)[strlen(*out)-3] = ':';
}

/*static int endsWith(const char *string, const char *suffix)
{
	if (strlen(string) < strlen(suffix))
	{
		return false;
	}
	return !strcmp(string + strlen(string) - strlen(suffix), suffix);
}*/

static int clock_dp_cb(const char *xpath, sr_val_t **values, size_t *values_cnt, void *private_ctx)
{
	char buf[TIME_BUF_SIZE];
	if (!private_ctx)
	{
		get_time_as_string(&buf);
	}
	else
	{
		strcpy(buf, private_ctx);
	}

	sr_val_t *value = calloc(1, sizeof(*value));
	if (!value)
	{
		return SR_ERR_NOMEM;
	}

	value->xpath = strdup(xpath);
	if (!value->xpath)
	{
		free(value);
		return SR_ERR_NOMEM;
	}
	value->type = SR_STRING_T;
	value->data.string_val = strdup(buf);
	if (!value->data.string_val)
	{
		free(value->xpath);
		free(value);
		return SR_ERR_NOMEM;
	}

    *values = value;
    *values_cnt = 1;
    return SR_ERR_OK;
}

enum platform_field
{
	PF_OS_NAME,
	PF_OS_RELEASE,
	PF_OS_VERSION,
	PF_MACHINE
};

static int platform_dp_cb(const char *xpath, sr_val_t **values, size_t *values_cnt, void *private_ctx)
{
	struct utsname data;
	uname(&data);
	const char *str;
	switch((enum platform_field)private_ctx)
	{
	case PF_OS_NAME: str = data.sysname; break;
	case PF_OS_RELEASE: str = data.release; break;
	case PF_OS_VERSION: str = data.version; break;
	case PF_MACHINE: str = data.machine; break;
	default:
		syslog(LOG_DEBUG, "Unrecognized context value for %s", __func__);
		return SR_ERR_NOT_FOUND;
	}


	sr_val_t *value = calloc(1, sizeof(*value));
	if (!value)
	{
		return SR_ERR_NOMEM;
	}

	value->xpath = strdup(xpath);
	if (!value->xpath)
	{
		free(value);
		return SR_ERR_NOMEM;
	}
	value->type = SR_STRING_T;
	value->data.string_val = strdup(str);
	if (!value->data.string_val)
	{
		free(value->xpath);
		free(value);
		return SR_ERR_NOMEM;
	}

    *values = value;
    *values_cnt = 1;
    return SR_ERR_OK;
}


int exec_rpc_cb(const char *xpath, const sr_val_t *input, const size_t input_cnt, sr_val_t **output, size_t *output_cnt, void *private_ctx)
{
	system(private_ctx);
	return SR_ERR_OK;
}


int
sr_plugin_init_cb(sr_session_ctx_t *session, void **private_ctx)
{
    sr_subscription_ctx_t *subscription = NULL;
    int rc = SR_ERR_OK;

    rc = sr_module_change_subscribe(session, "ietf-system", module_change_cb, NULL, 0,
            SR_SUBSCR_CTX_REUSE, &subscription);
    if (SR_ERR_OK != rc) {
        goto error;
    }

	get_time_as_string(&boottime);

    rc = sr_dp_get_items_subscribe(session, "/ietf-system:system-state/clock/current-datetime", clock_dp_cb, NULL, SR_SUBSCR_CTX_REUSE, &subscription);
    if (SR_ERR_OK != rc) goto error;

    rc = sr_dp_get_items_subscribe(session, "/ietf-system:system-state/clock/boot-datetime", clock_dp_cb, boottime, SR_SUBSCR_CTX_REUSE, &subscription);
    if (SR_ERR_OK != rc) goto error;

    rc = sr_dp_get_items_subscribe(session, "/ietf-system:system-state/platform/os-name", platform_dp_cb, (void*)PF_OS_NAME, SR_SUBSCR_CTX_REUSE, &subscription);
    if (SR_ERR_OK != rc) goto error;

    rc = sr_dp_get_items_subscribe(session, "/ietf-system:system-state/platform/os-release", platform_dp_cb, (void*)PF_OS_RELEASE, SR_SUBSCR_CTX_REUSE, &subscription);
    if (SR_ERR_OK != rc) goto error;

    rc = sr_dp_get_items_subscribe(session, "/ietf-system:system-state/platform/os-version", platform_dp_cb, (void*)PF_OS_VERSION, SR_SUBSCR_CTX_REUSE, &subscription);
    if (SR_ERR_OK != rc) goto error;

    rc = sr_dp_get_items_subscribe(session, "/ietf-system:system-state/platform/machine", platform_dp_cb, (void*)PF_MACHINE, SR_SUBSCR_CTX_REUSE, &subscription);
    if (SR_ERR_OK != rc) goto error;

    rc = sr_rpc_subscribe(session, "/ietf-system:system-restart", exec_rpc_cb, "shutdown -r now", SR_SUBSCR_CTX_REUSE, &subscription);
    if (SR_ERR_OK != rc) goto error;
    rc = sr_rpc_subscribe(session, "/ietf-system:system-shutdown", exec_rpc_cb, "shutdown -h now", SR_SUBSCR_CTX_REUSE, &subscription);
    if (SR_ERR_OK != rc) goto error;

    syslog(LOG_DEBUG, "plugin initialized successfully");

    retrieve_current_config(session);

    /* set subscription as our private context */
    *private_ctx = subscription;

    return SR_ERR_OK;

error:
    syslog(LOG_ERR, "plugin initialization failed: %s", sr_strerror(rc));
    sr_unsubscribe(session, subscription);
    return rc;
}

void
sr_plugin_cleanup_cb(sr_session_ctx_t *session, void *private_ctx)
{
    /* subscription was set as our private context */
    sr_unsubscribe(session, private_ctx);

    syslog(LOG_DEBUG, "plugin cleanup finished");
}