services: herdd: implement scanning and parsing of runlevel and service config files

services/herdd/CMakeLists.txt

@@ -1,6 +1,9 @@
 file(GLOB sources *.c)
 add_executable(herdd ${sources})
-target_link_libraries(herdd libc libc-runtime libmango libpthread)
+target_link_libraries(herdd
+	libc libc-runtime
+	libmango libpthread liblaunch librosetta
+	fx-core fx-ds fx-serial)
 
 sysroot_add_program(
 	NAME herdd

services/herdd/log.c

@@ -0,0 +1,31 @@
+#include <stdio.h>
+
+void log(const char *format, ...)
+{
+	fputs("         ", stdout);
+	va_list arg;
+	va_start(arg, format);
+	vprintf(format, arg);
+	va_end(arg);
+	fputc('\n', stdout);
+}
+
+void log_ok(const char *format, ...)
+{
+	fputs("[  OK  ] ", stdout);
+	va_list arg;
+	va_start(arg, format);
+	vprintf(format, arg);
+	va_end(arg);
+	fputc('\n', stdout);
+}
+
+void log_fail(const char *format, ...)
+{
+	fputs("[ FAIL ] ", stdout);
+	va_list arg;
+	va_start(arg, format);
+	vprintf(format, arg);
+	va_end(arg);
+	fputc('\n', stdout);
+}

services/herdd/log.h

@@ -0,0 +1,8 @@
+#ifndef LOG_H_
+#define LOG_H_
+
+extern void log(const char *format, ...);
+extern void log_ok(const char *format, ...);
+extern void log_fail(const char *format, ...);
+
+#endif

services/herdd/main.c

@@ -1,5 +1,14 @@
+#include "log.h"
+#include "queue.h"
+#include "runlevel.h"
+#include "service.h"
+
+#include <dirent.h>
 #include <errno.h>
+#include <fcntl.h>
+#include <fx/ds/string.h>
 #include <mango/log.h>
+#include <mango/task.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <string.h>
@@ -7,61 +16,117 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#ifdef TRACE
+#define tracef(...) printf(__VA_ARGS__)
+#else
+#define tracef(...)
+#endif
+
 static void *thread_func(void *arg)
 {
-	kern_logf("started thread with arg %p", arg);
+	tracef("started thread with arg %p\n", arg);
 	errno = 100;
+	tracef("thread done");
 	return (void *)0xdeadbeef;
 }
 
+static int load_services(const char *dir, struct queue *out)
+{
+	DIR *d = opendir(dir);
+	if (!d) {
+		printf("cannot open '%s': %s\n", dir, strerror(errno));
+		return -1;
+	}
+
+	struct dirent *dent = NULL;
+
+	while ((dent = readdir(d))) {
+		char filepath[4096];
+		snprintf(filepath, sizeof filepath, "%s/%s", dir, dent->d_name);
+		tracef(" - %s\n", dent->d_name);
+		struct service *s = NULL;
+		int err = service_load(filepath, &s);
+		if (err != SUCCESS) {
+			printf("failed to load %s (%s)\n",
+			       filepath,
+			       strerror(errno));
+		}
+
+		queue_push_back(out, &s->s_entry);
+	}
+
+	closedir(d);
+	return SUCCESS;
+}
+
+static int load_runlevels(const char *dir, struct queue *out)
+{
+	DIR *d = opendir(dir);
+	if (!d) {
+		printf("cannot open '%s': %s\n", dir, strerror(errno));
+		return -1;
+	}
+
+	struct dirent *dent = NULL;
+
+	while ((dent = readdir(d))) {
+		char filepath[4096];
+		snprintf(filepath, sizeof filepath, "%s/%s", dir, dent->d_name);
+		tracef(" - %s\n", dent->d_name);
+		struct runlevel *rl = NULL;
+		int err = runlevel_load(filepath, &rl);
+		if (err != SUCCESS) {
+			printf("failed to load %s (%s)\n",
+			       filepath,
+			       strerror(errno));
+			continue;
+		}
+
+		tracef("runlevel: %s\n", rl->rl_description);
+		for (size_t i = 0; i < rl->rl_requires_count; i++) {
+			tracef("  requires: %s\n", rl->rl_requires[i]);
+		}
+
+		queue_push_back(out, &rl->rl_entry);
+	}
+
+	closedir(d);
+	return SUCCESS;
+}
+
 int main(int argc, const char *argv[], const char *envp[])
 {
 	sys_remote_set(SYS_REMOTE_NSD, 0, 0);
 
-	kern_logf("herdd");
+	struct queue *runlevels = global_runlevels();
-	kern_logf("args:");
+	struct queue *services = global_services();
 
-	for (int i = 0; i < argc; i++) {
+	int err = load_runlevels("/etc/herdd/runlevels", runlevels);
-		kern_logf("[%d]: %s", i, argv[i]);
+	err = load_services("/etc/herdd/services", services);
+
+	struct runlevel *rl = runlevel_find("single-user");
+	if (!rl) {
+		log_fail("Cannot find runlevel single-user.");
+		return -1;
 	}
 
-	kern_logf("env:");
+	runlevel_activate(rl);
 
-	for (int i = 0; envp[i]; i++) {
+	kern_handle_t new_task = 123, new_space = 456;
-		kern_logf("[%d]: %s", i, envp[i]);
+	kern_status_t status = task_duplicate(&new_task, &new_space);
-	}
+	kern_logf(
+		"  task_duplicate returned %d (%x/%x)",
+		status,
+		new_task,
+		new_space);
 
-	kern_logf("self = %p", pthread_self());
+	if (new_task == KERN_HANDLE_INVALID) {
-	errno = 200;
+		kern_log("this is the child");
-
-#if 1
-	int dir = open("/", 0);
-	if (dir >= 0) {
-		kern_logf("opened '/'");
-		char buf[4096] = {0};
-		struct dentry *dent = (struct dentry *)buf;
-		long len = getdents(dir, dent, sizeof buf);
-		if (len < 0) {
-			kern_logf("getdents failed (%s)", strerror(errno));
-		} else {
-			for (long i = 0; i < len;) {
-				dent = (struct dentry *)(buf + i);
-				kern_logf(" - %s", dent->d_name);
-				i += dent->d_reclen;
-			}
-		}
-		close(dir);
 	} else {
-		kern_logf("open() failed: %s", strerror(errno));
+		kern_log("this is the parent");
 	}
-#endif
 
-	pthread_t thread;
+	printf("hello\n");
-	pthread_create(&thread, NULL, thread_func, (void *)0xdeafcafe);
-	kern_logf("started thread %p", thread);
-	void *ret = NULL;
-	pthread_join(thread, &ret);
-	kern_logf("thread returned %p", ret);
 
 	return 0;
 }

services/herdd/queue.c

@@ -0,0 +1,138 @@
+#include "queue.h"
+
+size_t queue_length(struct queue *q)
+{
+	size_t i = 0;
+	struct queue_entry *x = q->q_first;
+	while (x) {
+		i++;
+		x = x->qe_next;
+	}
+
+	return i;
+}
+
+void queue_insert_before(
+	struct queue *q,
+	struct queue_entry *entry,
+	struct queue_entry *before)
+{
+	struct queue_entry *x = before->qe_prev;
+	if (x) {
+		x->qe_next = entry;
+	} else {
+		q->q_first = entry;
+	}
+
+	entry->qe_prev = x;
+
+	before->qe_prev = entry;
+	entry->qe_next = before;
+}
+
+void queue_insert_after(
+	struct queue *q,
+	struct queue_entry *entry,
+	struct queue_entry *after)
+{
+	struct queue_entry *x = after->qe_next;
+	if (x) {
+		x->qe_prev = entry;
+	} else {
+		q->q_last = entry;
+	}
+
+	entry->qe_prev = x;
+
+	after->qe_next = entry;
+	entry->qe_prev = after;
+}
+
+void queue_push_front(struct queue *q, struct queue_entry *entry)
+{
+	if (q->q_first) {
+		q->q_first->qe_prev = entry;
+	}
+
+	entry->qe_next = q->q_first;
+	entry->qe_prev = NULL;
+
+	q->q_first = entry;
+
+	if (!q->q_last) {
+		q->q_last = entry;
+	}
+}
+
+void queue_push_back(struct queue *q, struct queue_entry *entry)
+{
+	if (q->q_last) {
+		q->q_last->qe_next = entry;
+	}
+
+	entry->qe_prev = q->q_last;
+	entry->qe_next = NULL;
+
+	q->q_last = entry;
+
+	if (!q->q_first) {
+		q->q_first = entry;
+	}
+}
+
+struct queue_entry *queue_pop_front(struct queue *q)
+{
+	struct queue_entry *x = q->q_first;
+	if (x) {
+		queue_delete(q, x);
+	}
+
+	return x;
+}
+
+struct queue_entry *queue_pop_back(struct queue *q)
+{
+	struct queue_entry *x = q->q_last;
+	if (x) {
+		queue_delete(q, x);
+	}
+
+	return x;
+}
+
+void queue_delete(struct queue *q, struct queue_entry *entry)
+{
+	if (!entry) {
+		return;
+	}
+
+	if (entry == q->q_first) {
+		q->q_first = q->q_first->qe_next;
+	}
+
+	if (entry == q->q_last) {
+		q->q_last = q->q_last->qe_prev;
+	}
+
+	if (entry->qe_next) {
+		entry->qe_next->qe_prev = entry->qe_prev;
+	}
+
+	if (entry->qe_prev) {
+		entry->qe_prev->qe_next = entry->qe_next;
+	}
+
+	entry->qe_next = entry->qe_prev = NULL;
+}
+
+void queue_delete_all(struct queue *q)
+{
+	struct queue_entry *x = q->q_first;
+	while (x) {
+		struct queue_entry *next = x->qe_next;
+		x->qe_next = x->qe_prev = NULL;
+		x = next;
+	}
+
+	q->q_first = q->q_last = NULL;
+}

services/herdd/queue.h

@@ -0,0 +1,100 @@
+#ifndef QUEUE_H_
+#define QUEUE_H_
+
+#include <stdbool.h>
+#include <string.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define QUEUE_CONTAINER(t, m, v)                                               \
+	((void *)((v) ? (uintptr_t)(v) - (offsetof(t, m)) : 0))
+
+#define QUEUE_INIT ((struct queue) {.q_first = NULL, .q_last = NULL})
+#define QUEUE_ENTRY_INIT                                                       \
+	((struct queue_entry) {.qe_next = NULL, .qe_prev = NULL})
+
+#define queue_foreach(iter_type, iter_name, queue_name, node_member)           \
+	for (iter_type *iter_name = (iter_type *)QUEUE_CONTAINER(              \
+		     iter_type,                                                \
+		     node_member,                                              \
+		     queue_first(queue_name));                                 \
+	     iter_name;                                                        \
+	     iter_name = (iter_type *)QUEUE_CONTAINER(                         \
+		     iter_type,                                                \
+		     node_member,                                              \
+		     queue_next(&((iter_name)->node_member))))
+
+#define queue_foreach_r(iter_type, iter_name, queue_name, node_member)         \
+	for (iter_type *iter_name = (iter_type *)QUEUE_CONTAINER(              \
+		     iter_type,                                                \
+		     node_member,                                              \
+		     queue_last(queue_name));                                  \
+	     iter_name;                                                        \
+	     iter_name = (iter_type *)QUEUE_CONTAINER(                         \
+		     iter_type,                                                \
+		     node_member,                                              \
+		     queue_prev(&((iter_name)->node_member))))
+
+struct queue_entry {
+	struct queue_entry *qe_next;
+	struct queue_entry *qe_prev;
+};
+
+struct queue {
+	struct queue_entry *q_first;
+	struct queue_entry *q_last;
+};
+
+static inline void queue_init(struct queue *q)
+{
+	memset(q, 0x00, sizeof *q);
+}
+static inline bool queue_empty(struct queue *q)
+{
+	return q->q_first == NULL;
+}
+
+static inline struct queue_entry *queue_first(struct queue *q)
+{
+	return q->q_first;
+}
+static inline struct queue_entry *queue_last(struct queue *q)
+{
+	return q->q_last;
+}
+static inline struct queue_entry *queue_next(struct queue_entry *entry)
+{
+	return entry->qe_next;
+}
+static inline struct queue_entry *queue_prev(struct queue_entry *entry)
+{
+	return entry->qe_prev;
+}
+
+extern size_t queue_length(struct queue *q);
+
+extern void queue_insert_before(
+	struct queue *q,
+	struct queue_entry *entry,
+	struct queue_entry *before);
+extern void queue_insert_after(
+	struct queue *q,
+	struct queue_entry *entry,
+	struct queue_entry *after);
+
+extern void queue_push_front(struct queue *q, struct queue_entry *entry);
+extern void queue_push_back(struct queue *q, struct queue_entry *entry);
+
+extern struct queue_entry *queue_pop_front(struct queue *q);
+extern struct queue_entry *queue_pop_back(struct queue *q);
+
+extern void queue_delete(struct queue *q, struct queue_entry *entry);
+extern void queue_delete_all(struct queue *q);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

services/herdd/runlevel.c

@@ -0,0 +1,154 @@
+#include "runlevel.h"
+
+#include "log.h"
+#include "service.h"
+
+#include <errno.h>
+#include <fx/core/stringstream.h>
+#include <fx/ds/array.h>
+#include <fx/ds/dict.h>
+#include <fx/serial.h>
+#include <mango/log.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static struct queue runlevels = QUEUE_INIT;
+
+struct queue *global_runlevels(void)
+{
+	return &runlevels;
+}
+
+static int parse_runlevel_data(fx_object *in, struct runlevel *out)
+{
+	if (!fx_object_is_type(in, FX_TYPE_DICT)) {
+		return -1;
+	}
+
+	fx_dict *in_runlevel = fx_dict_at(in, "runlevel");
+	if (!in_runlevel || !fx_object_is_type(in_runlevel, FX_TYPE_DICT)) {
+		return -1;
+	}
+
+	fx_string *name = fx_dict_at(in_runlevel, "name");
+	if (!name || !fx_object_is_type(name, FX_TYPE_STRING)) {
+		return -1;
+	}
+
+	fx_string *description = fx_dict_at(in_runlevel, "description");
+	if (!description || !fx_object_is_type(description, FX_TYPE_STRING)) {
+		return -1;
+	}
+
+	fx_array *deps = fx_dict_at(in_runlevel, "requires");
+	if (deps && !fx_object_is_type(deps, FX_TYPE_ARRAY)) {
+		return -1;
+	}
+
+	int ret = 0;
+	size_t dep_count = fx_array_size(deps);
+	fx_iterator *it = fx_iterator_begin(deps);
+	fx_foreach_ptr(fx_string, dep, it)
+	{
+		if (!fx_object_is_type(dep, FX_TYPE_STRING)) {
+			ret = -1;
+			break;
+		}
+	}
+	fx_iterator_unref(it);
+
+	if (ret != 0) {
+		return ret;
+	}
+
+	out->rl_requires_count = dep_count;
+	out->rl_requires = calloc(dep_count, sizeof(char *));
+	it = fx_iterator_begin(deps);
+	size_t i = 0;
+	fx_foreach_ptr(fx_string, dep, it)
+	{
+		out->rl_requires[i++] = fx_string_steal(dep);
+	}
+	fx_iterator_unref(it);
+
+	out->rl_name = fx_string_steal(name);
+	out->rl_description = fx_string_steal(description);
+
+	return 0;
+}
+
+int runlevel_load(const char *path, struct runlevel **out)
+{
+	struct runlevel *rl = malloc(sizeof *rl);
+	if (!rl) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	FILE *fp = fopen(path, "r");
+	if (!fp) {
+		free(rl);
+		return -1;
+	}
+
+	fx_stream *in = fx_stream_open_fp(fp);
+	fx_serial_ctx *ctx = fx_toml_serial_ctx_create();
+	fx_object *data;
+	fx_status status = fx_serial_ctx_deserialise(ctx, in, &data, 0);
+	if (!FX_OK(status)) {
+		free(rl);
+		errno = EFTYPE;
+		return -1;
+	}
+
+	if (parse_runlevel_data(data, rl) != 0) {
+		free(rl);
+		errno = EFTYPE;
+		return -1;
+	}
+
+	fx_stream_unref(in);
+	fx_object_unref(data);
+
+	fclose(fp);
+
+	*out = rl;
+	return 0;
+}
+
+struct runlevel *runlevel_find(const char *name)
+{
+	struct queue_entry *cur = queue_first(&runlevels);
+	while (cur) {
+		struct runlevel *rl
+			= QUEUE_CONTAINER(struct runlevel, rl_entry, cur);
+		if (!strcmp(rl->rl_name, name)) {
+			return rl;
+		}
+
+		cur = queue_next(cur);
+	}
+
+	return NULL;
+}
+
+int runlevel_activate(struct runlevel *rl)
+{
+	for (size_t i = 0; i < rl->rl_requires_count; i++) {
+		const char *svc_name = rl->rl_requires[i];
+		struct service *svc = service_find(svc_name);
+		if (!svc) {
+			log_fail("Cannot find service %s.", svc_name);
+			return -1;
+		}
+
+		int ret = service_start(svc);
+		if (ret != 0) {
+			return ret;
+		}
+	}
+
+	log_ok("Reached runlevel %s.", rl->rl_description);
+	return 0;
+}

services/herdd/runlevel.h

@@ -1,14 +1,22 @@
 #ifndef RUNLEVEL_H_
 #define RUNLEVEL_H_
 
+#include "queue.h"
+
 #include <stddef.h>
 
-#define RUNLEVEL_DESCRIPTION_MAX 64
-
 struct runlevel {
-	char rl_description[RUNLEVEL_DESCRIPTION_MAX];
+	char *rl_name;
+	char *rl_description;
 	char **rl_requires;
 	size_t rl_requires_count;
+	struct queue_entry rl_entry;
 };
 
+extern struct queue *global_runlevels(void);
+
+extern int runlevel_load(const char *path, struct runlevel **out);
+extern struct runlevel *runlevel_find(const char *name);
+extern int runlevel_activate(struct runlevel *rl);
+
 #endif

services/herdd/service.c

@@ -0,0 +1,154 @@
+#include "service.h"
+
+#include "log.h"
+
+#include <errno.h>
+#include <fx/core/stringstream.h>
+#include <fx/ds/array.h>
+#include <fx/ds/dict.h>
+#include <fx/serial.h>
+#include <launch.h>
+#include <mango/log.h>
+#include <rosetta/bootstrap.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static struct queue services = QUEUE_INIT;
+
+struct queue *global_services(void)
+{
+	return &services;
+}
+
+static int parse_service_data(fx_object *in, struct service *out)
+{
+	if (!fx_object_is_type(in, FX_TYPE_DICT)) {
+		return -1;
+	}
+
+	fx_dict *in_service = fx_dict_at(in, "service");
+	if (!in_service || !fx_object_is_type(in_service, FX_TYPE_DICT)) {
+		return -1;
+	}
+
+	fx_dict *in_unit = fx_dict_at(in, "unit");
+	if (!in_unit || !fx_object_is_type(in_unit, FX_TYPE_DICT)) {
+		return -1;
+	}
+
+	fx_string *name = fx_dict_at(in_unit, "name");
+	if (!name || !fx_object_is_type(name, FX_TYPE_STRING)) {
+		return -1;
+	}
+
+	fx_string *description = fx_dict_at(in_unit, "description");
+	if (!description || !fx_object_is_type(description, FX_TYPE_STRING)) {
+		return -1;
+	}
+
+	fx_string *exec = fx_dict_at(in_service, "exec");
+	if (!description || !fx_object_is_type(description, FX_TYPE_STRING)) {
+		return -1;
+	}
+
+	fx_array *roles = fx_dict_at(in_service, "roles");
+	if (roles && !fx_object_is_type(roles, FX_TYPE_ARRAY)) {
+		return -1;
+	}
+
+	int ret = 0;
+	fx_iterator *it = fx_iterator_begin(roles);
+	fx_foreach_ptr(fx_string, role, it)
+	{
+		if (!fx_object_is_type(role, FX_TYPE_STRING)) {
+			ret = -1;
+			break;
+		}
+	}
+	fx_iterator_unref(it);
+
+	if (ret != 0) {
+		return ret;
+	}
+
+	it = fx_iterator_begin(roles);
+	size_t i = 0;
+	fx_foreach_ptr(fx_string, role, it)
+	{
+		const char *role_cstr = fx_string_ptr(role);
+		if (!strcmp(role_cstr, "NamespaceProvider")) {
+			out->s_roles |= SVC_ROLE_NAMESPACE_PROVIDER;
+		}
+	}
+	fx_iterator_unref(it);
+
+	out->s_name = fx_string_steal(name);
+	out->s_description = fx_string_steal(description);
+	out->s_exec = fx_string_steal(exec);
+
+	return 0;
+}
+
+int service_load(const char *path, struct service **out)
+{
+	struct service *rl = malloc(sizeof *rl);
+	if (!rl) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	FILE *fp = fopen(path, "r");
+	if (!fp) {
+		free(rl);
+		return -1;
+	}
+
+	fx_stream *in = fx_stream_open_fp(fp);
+	fx_serial_ctx *ctx = fx_toml_serial_ctx_create();
+	fx_object *data;
+	fx_status status = fx_serial_ctx_deserialise(ctx, in, &data, 0);
+	if (!FX_OK(status)) {
+		free(rl);
+		errno = EFTYPE;
+		return -1;
+	}
+
+	if (parse_service_data(data, rl) != 0) {
+		free(rl);
+		errno = EFTYPE;
+		return -1;
+	}
+
+	fx_stream_unref(in);
+	fx_object_unref(data);
+
+	fclose(fp);
+
+	*out = rl;
+	return 0;
+}
+
+struct service *service_find(const char *name)
+{
+	struct queue_entry *cur = queue_first(&services);
+	while (cur) {
+		struct service *s
+			= QUEUE_CONTAINER(struct service, s_entry, cur);
+		if (!strcmp(s->s_name, name)) {
+			return s;
+		}
+
+		cur = queue_next(cur);
+	}
+
+	return NULL;
+}
+
+int service_start(struct service *svc)
+{
+	log("Starting %s...", svc->s_description);
+
+	log_ok("Started %s.", svc->s_description);
+	return 0;
+}

services/herdd/service.h

@@ -1,17 +1,24 @@
 #ifndef SERVICE_H_
 #define SERVICE_H_
 
-#define SVC_DESCRIPTION_MAX 64
+#include "queue.h"
-
 enum service_role {
 	SVC_ROLE_NONE = 0x00u,
 	SVC_ROLE_NAMESPACE_PROVIDER = 0x01u,
 };
 
 struct service {
-	char s_description[SVC_DESCRIPTION_MAX];
+	char *s_name;
-	enum service_role s_roles;
+	char *s_description;
 	char *s_exec;
+	enum service_role s_roles;
+	struct queue_entry s_entry;
 };
 
+extern struct queue *global_services(void);
+
+extern int service_load(const char *path, struct service **out);
+extern struct service *service_find(const char *name);
+extern int service_start(struct service *svc);
+
 #endif