irmd: Revise IRMd internals

This is a full revision of the IRMd internal implementation.

The registry is now a proper subcomponent managing its own internal
lock (a single mutex). Some tests are added for the registry and its
data structures. Some macros for tests are added in <ouroboros/test.h>.

Flow allocation is now more symmetric between the client side (alloc)
and server size (accept). Each will create a flow in pending state
(ALLOC_PENDING/ACCEPT_PENDING) that is potentially fulfilled by an
IPCP using respond_alloc and respond_accept primitives. Deallocation
is split in flow_dealloc (application side) and ipcp_flow_dealloc
(IPCP side) to get the flow in DEALLOC_PENDING and DEALLOCATED state.

Cleanup of failed flow allocation is now properly handled instead of
relying on the sanitizer thread. The new sanitizer only needs to
monitor crashed processes.

On shutdown, the IRMd will now detect hanging processes and SIGKILL
them and clean up their fuse mountpoints if needed.

A lot of other things have been cleaned up and shuffled around a bit.

Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

1 files changed, 94 insertions, 172 deletions

diff --git a/src/irmd/reg/proc.c b/src/irmd/reg/proc.c
index ede69b8a..24d10fc1 100644
--- a/src/irmd/reg/proc.c
+++ b/src/irmd/reg/proc.c
@@ -6,256 +6,178 @@
  *    Dimitri Staessens <dimitri@ouroboros.rocks>
  *    Sander Vrijders   <sander@ouroboros.rocks>
  *
- * This program is free software; you can redistribute it and/or modify
+ * This procram is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
- * This program is distributed in the hope that it will be useful,
+ * This procram is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
+ * along with this procram; if not, write to the Free Software
  * Foundation, Inc., http://www.fsf.org/about/contact/.
  */
 
-#if defined(__linux__) || defined(__CYGWIN__)
-#define _DEFAULT_SOURCE
-#else
-#define _POSIX_C_SOURCE 200112L
-#endif
+#define _POSIX_C_SOURCE 200809L
 
-#include "config.h"
+#define OUROBOROS_PREFIX "reg/proc"
 
-#include <ouroboros/list.h>
-#include <ouroboros/errno.h>
-#include <ouroboros/time_utils.h>
+#include <ouroboros/logs.h>
 
 #include "proc.h"
-#include "name.h"
 
-#include <stdlib.h>
-#include <unistd.h>
-#include <limits.h>
 #include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct name_entry {
+        struct list_head next;
+        char *           name;
+};
 
-struct reg_proc * reg_proc_create(pid_t        pid,
-                                  const char * prog)
+static void __free_name_entry(struct name_entry * entry)
 {
-        struct reg_proc *  proc;
-        pthread_condattr_t cattr;
+        assert(entry != NULL);
+        assert(entry->name != NULL);
 
-        assert(prog);
+        free(entry->name);
+        free(entry);
+}
 
-        proc = malloc(sizeof(*proc));
-        if (proc == NULL)
-                goto fail_malloc;
+static void __reg_proc_clear_names(struct reg_proc * proc)
+{
+        struct list_head * p;
+        struct list_head * h;
 
-        if (pthread_condattr_init(&cattr))
-                goto fail_condattr;
+        assert(proc != NULL);
 
-#ifndef __APPLE__
-        pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK);
-#endif
+        list_for_each_safe(p, h, &proc->names) {
+                struct name_entry * entry;
+                entry = list_entry(p, struct name_entry, next);
+                list_del(&entry->next);
+                __free_name_entry(entry);
+                proc->n_names--;
+        }
+}
 
-        if (pthread_mutex_init(&proc->lock, NULL))
-                goto fail_mutex;
+struct reg_proc * reg_proc_create(const struct proc_info * info)
+{
+        struct reg_proc * proc;
 
-        if (pthread_cond_init(&proc->cond, &cattr))
-                goto fail_cond;
+        assert(info != NULL);
 
-        proc->set = shm_flow_set_create(pid);
-        if (proc->set == NULL)
-                goto fail_set;
+        proc = malloc(sizeof(*proc));
+        if (proc == NULL) {
+                log_err("Failed to malloc proc.");
+                goto fail_malloc;
+        }
 
-        proc->prog = strdup(prog);
-        if(proc->prog == NULL)
-                goto fail_prog;
+        proc->set = shm_flow_set_create(info->pid);
+        if (proc->set == NULL) {
+                log_err("Failed to create flow set for %d.", info->pid);
+                goto fail_set;
+        }
 
         list_head_init(&proc->next);
         list_head_init(&proc->names);
 
-        proc->pid      = pid;
-        proc->name     = NULL;
-        proc->state    = PROC_INIT;
+        proc->info    = *info;
+        proc->n_names = 0;
 
         return proc;
 
- fail_prog:
-        shm_flow_set_destroy(proc->set);
  fail_set:
-        pthread_cond_destroy(&proc->cond);;
- fail_cond:
-        pthread_mutex_destroy(&proc->lock);
- fail_mutex:
-        pthread_condattr_destroy(&cattr);
- fail_condattr:
         free(proc);
  fail_malloc:
         return NULL;
 }
 
-static void cancel_reg_proc(void * o)
-{
-        struct reg_proc * proc = (struct reg_proc *) o;
-
-        proc->state = PROC_NULL;
-
-        pthread_mutex_unlock(&proc->lock);
-}
-
 void reg_proc_destroy(struct reg_proc * proc)
 {
-        struct list_head * p;
-        struct list_head * h;
+        assert(proc != NULL);
 
-        assert(proc);
-
-        pthread_mutex_lock(&proc->lock);
-
-        if (proc->state == PROC_DESTROY) {
-                pthread_mutex_unlock(&proc->lock);
-                return;
-        }
-
-        if (proc->state == PROC_SLEEP)
-                proc->state = PROC_DESTROY;
-
-        pthread_cond_signal(&proc->cond);
+        shm_flow_set_destroy(proc->set);
 
-        pthread_cleanup_push(cancel_reg_proc, proc);
+        __reg_proc_clear_names(proc);
 
-        while (proc->state != PROC_INIT)
-                pthread_cond_wait(&proc->cond, &proc->lock);
+        assert(list_is_empty(&proc->next));
 
-        pthread_cleanup_pop(false);
+        assert(proc->n_names == 0);
 
-        pthread_mutex_unlock(&proc->lock);
+        assert(list_is_empty(&proc->names));
 
-        shm_flow_set_destroy(proc->set);
+        free(proc);
+}
 
-        pthread_cond_destroy(&proc->cond);
-        pthread_mutex_destroy(&proc->lock);
+static struct name_entry * __reg_proc_get_name(const struct reg_proc * proc,
+                                               const char *            name)
+{
+        struct list_head * p;
 
-        list_for_each_safe(p, h, &proc->names) {
-                struct str_el * n = list_entry(p, struct str_el, next);
-                list_del(&n->next);
-                if (n->str != NULL)
-                        free(n->str);
-                free(n);
+        list_for_each(p, &proc->names) {
+                struct name_entry * entry;
+                entry = list_entry(p, struct name_entry, next);
+                if (strcmp(entry->name, name) == 0)
+                        return entry;
         }
 
-        free(proc->prog);
-        free(proc);
+        return NULL;
 }
 
 int reg_proc_add_name(struct reg_proc * proc,
                       const char *      name)
 {
-        struct str_el * s;
+        struct name_entry * entry;
 
-        assert(proc);
-        assert(name);
+        assert(__reg_proc_get_name(proc, name) == NULL);
 
-        s = malloc(sizeof(*s));
-        if (s == NULL)
+        entry = malloc(sizeof(*entry));
+        if (entry == NULL) {
+                log_err("Failed to malloc name.");
                 goto fail_malloc;
+        }
 
-        s->str = strdup(name);
-        if (s->str == NULL)
+        entry->name = strdup(name);
+        if (entry == NULL) {
+                log_err("Failed to strdup name.");
                 goto fail_name;
+        }
+
+        list_add(&entry->next, &proc->names);
 
-        list_add(&s->next, &proc->names);
+        proc->n_names++;
 
         return 0;
 
  fail_name:
-        free(s);
+        free(entry);
  fail_malloc:
-        return -ENOMEM;
+        return -1;
 }
 
 void reg_proc_del_name(struct reg_proc * proc,
                        const char *      name)
 {
-        struct list_head * p = NULL;
-        struct list_head * h = NULL;
-
-        assert(proc);
-        assert(name);
-
-        list_for_each_safe(p, h, &proc->names) {
-                struct str_el * s = list_entry(p, struct str_el, next);
-                if (!strcmp(name, s->str)) {
-                        list_del(&s->next);
-                        free(s->str);
-                        free(s);
-                }
-        }
-}
-
-int reg_proc_sleep(struct reg_proc * proc,
-                   struct timespec * dl)
-{
-
-        int ret = 0;
-
-        assert(proc);
+        struct name_entry * entry;
 
-        pthread_mutex_lock(&proc->lock);
-
-        if (proc->state != PROC_WAKE && proc->state != PROC_DESTROY)
-                proc->state = PROC_SLEEP;
-
-        pthread_cleanup_push(cancel_reg_proc, proc);
-
-        while (proc->state == PROC_SLEEP && ret != -ETIMEDOUT)
-                ret = -__timedwait(&proc->cond, &proc->lock, dl);
+        entry = __reg_proc_get_name(proc, name);
+        if(entry == NULL)
+                return;
 
-        pthread_cleanup_pop(false);
+        list_del(&entry->next);
 
-        if (proc->state == PROC_DESTROY) {
-                if (proc->name != NULL)
-                        reg_name_del_pid(proc->name, proc->pid);
-                ret = -1;
-        }
+        __free_name_entry(entry);
 
-        proc->state = PROC_INIT;
+        proc->n_names--;
 
-        pthread_cond_broadcast(&proc->cond);
-        pthread_mutex_unlock(&proc->lock);
-
-        return ret;
+        assert(__reg_proc_get_name(proc, name) == NULL);
 }
 
-void reg_proc_wake(struct reg_proc * proc,
-                   struct reg_name * name)
+bool reg_proc_has_name(const struct reg_proc * proc,
+                       const char *            name)
 {
-        assert(proc);
-        assert(name);
-
-        pthread_mutex_lock(&proc->lock);
-
-        if (proc->state != PROC_SLEEP) {
-                pthread_mutex_unlock(&proc->lock);
-                return;
-        }
-
-        proc->state = PROC_WAKE;
-        proc->name  = name;
-
-        pthread_cond_broadcast(&proc->cond);
-
-        pthread_cleanup_push(cancel_reg_proc, proc);
-
-        while (proc->state == PROC_WAKE)
-                pthread_cond_wait(&proc->cond, &proc->lock);
-
-        pthread_cleanup_pop(false);
-
-        if (proc->state == PROC_DESTROY)
-                proc->state = PROC_INIT;
-
-        pthread_mutex_unlock(&proc->lock);
-}
+        return __reg_proc_get_name(proc, name) != NULL;
+}
\ No newline at end of file