Implement environment variables

kernel/amd64/proc.c

@@ -11,6 +11,7 @@
 #include <limine/requests.h>
 #include <mm/malloc.h>
 #include <mm/pmm.h>
+#include <proc/env.h>
 #include <proc/mutex.h>
 #include <proc/proc.h>
 #include <proc/procgroup.h>
@@ -138,6 +139,8 @@ void proc_cleanup (struct proc* proc, struct reschedule_ctx* rctx) {
   proc_sqs_cleanup (proc);
   proc_mutexes_cleanup (proc, rctx);
 
+  proc_env_cleanup (proc);
+
   pmm_free (proc->pdata.kernel_stack, KSTACK_SIZE / PAGE_SIZE);
   procgroup_unmap (proc->procgroup, proc->pdata.tls_vaddr, proc->procgroup->tls.tls_tmpl_pages);
 

kernel/proc/env.c

@@ -0,0 +1,83 @@
+#include <libk/fieldlengthof.h>
+#include <libk/hash.h>
+#include <libk/lengthof.h>
+#include <libk/minmax.h>
+#include <libk/std.h>
+#include <libk/string.h>
+#include <mm/malloc.h>
+#include <proc/env.h>
+#include <proc/proc.h>
+#include <status.h>
+
+void proc_env_cleanup (struct proc* proc) {
+  for (size_t i = 0; i < fieldlengthof (struct proc_env, env_var_buckets); i++) {
+    struct hash_node_link* link = proc->env.env_var_buckets[i];
+
+    if (link == NULL)
+      continue;
+
+    struct proc_env_var* var = hash_entry (link, struct proc_env_var, env_link);
+
+    free (var->buffer);
+    free (var);
+  }
+}
+
+int proc_env_set (struct proc* proc, const char* key, void* buffer, size_t data_size) {
+  uint64_t fp;
+
+  struct proc_env_var* var = malloc (sizeof (*var));
+
+  if (var == NULL)
+    return -ST_OOM_ERROR;
+
+  memset (var, 0, sizeof (*var));
+
+  var->buffer = malloc (data_size);
+
+  if (var->buffer == NULL) {
+    free (var);
+    return -ST_OOM_ERROR;
+  }
+
+  var->data_size = data_size;
+  memcpy (var->key, key, strlen_null (key));
+  memcpy (var->buffer, buffer, data_size);
+
+  uint32_t env_hash = hash_fnv32 (var->key, strlen_null (var->key));
+
+  spin_lock (&proc->lock, &fp);
+
+  hash_insert (&proc->env, &var->env_link, env_hash, lengthof (proc->env.env_var_buckets),
+               env_var_buckets);
+
+  spin_unlock (&proc->lock, fp);
+
+  return ST_OK;
+}
+
+int proc_env_get (struct proc* proc, const char* key, void* buffer, size_t size) {
+  uint64_t fp;
+
+  struct hash_node_link* found_link = NULL;
+  size_t key_len = strlen_null (key);
+  uint32_t hash = hash_fnv32 (key, key_len);
+
+  spin_lock (&proc->lock, &fp);
+
+  hash_find (&proc->env, key, key_len, hash, lengthof (proc->env.env_var_buckets), env_var_buckets,
+             struct proc_env_var, env_link, key, found_link);
+
+  if (found_link == NULL) {
+    spin_unlock (&proc->lock, fp);
+    return -ST_NOT_FOUND;
+  }
+
+  struct proc_env_var* var = hash_entry (found_link, struct proc_env_var, env_link);
+
+  memcpy (buffer, var->buffer, min (size, var->data_size));
+
+  spin_unlock (&proc->lock, fp);
+
+  return ST_OK;
+}

kernel/proc/env.h

@@ -0,0 +1,28 @@
+#ifndef _KERNEL_PROC_ENV_H
+#define _KERNEL_PROC_ENV_H
+
+#include <libk/hash.h>
+#include <libk/std.h>
+
+#define PROC_ENV_VAR_MAX 128
+
+struct proc;
+
+struct proc_env_var {
+  char key[PROC_ENV_VAR_MAX];
+  void* buffer;
+  size_t data_size;
+  struct hash_node_link env_link;
+};
+
+struct proc_env {
+  struct hash_node_link* env_var_buckets[64];
+};
+
+void proc_env_cleanup (struct proc* proc);
+
+int proc_env_set (struct proc* proc, const char* key, void* buffer, size_t data_size);
+
+int proc_env_get (struct proc* proc, const char* key, void* buffer, size_t size);
+
+#endif // _KERNEL_PROC_ENV_H

kernel/proc/proc.h

@@ -7,6 +7,7 @@
 #include <libk/rbtree.h>
 #include <libk/std.h>
 #include <path_defs.h>
+#include <proc/env.h>
 #include <proc/procgroup.h>
 #include <proc/resource.h>
 #include <proc/suspension_q.h>
@@ -48,6 +49,7 @@ struct proc {
   size_t mail_recv_size;
   char cwv[VOLUME_MAX];
   struct proc_suspension_q done_sq;
+  struct proc_env env;
 };
 
 void proc_sched (void);

kernel/proc/src.mk

@@ -3,11 +3,13 @@ c += proc/proc.c \
 		 proc/mutex.c \
 		 proc/procgroup.c \
 		 proc/suspension_q.c \
-		 proc/mail.c
+		 proc/mail.c \
+		 proc/env.c
 
 o += proc/proc.o \
 		 proc/resource.o \
 		 proc/mutex.o \
 		 proc/procgroup.o \
 		 proc/suspension_q.o \
-		 proc/mail.o
+		 proc/mail.o \
+		 proc/env.o

kernel/syscall/syscall.c

@@ -827,6 +827,80 @@ DEFINE_SYSCALL (sys_create_volume) {
   return SYSRESULT (vfs_create_volume (proc, rctx, key, type, device, false));
 }
 
+/* int env_set (char* key, void* buffer, size_t size) */
+DEFINE_SYSCALL (sys_env_set) {
+  uint64_t fp, fpg;
+
+  uintptr_t uvaddr_key = a1;
+  uintptr_t uvaddr_buffer = a2;
+  size_t size = (size_t)a3;
+
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  uintptr_t out_paddr;
+
+  spin_lock (&proc->lock, &fp);
+  struct procgroup* procgroup = proc->procgroup;
+  spin_unlock (&proc->lock, fp);
+
+  spin_lock (&procgroup->lock, &fpg);
+
+  out_paddr = mm_v2p (&procgroup->pd, uvaddr_key);
+
+  if (out_paddr == 0) {
+    spin_unlock (&procgroup->lock, fpg);
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+  }
+
+  const char* key = (const char*)((uintptr_t)hhdm->offset + out_paddr);
+
+  spin_unlock (&procgroup->lock, fpg);
+
+  void* buffer = sys_get_user_buffer (procgroup, uvaddr_buffer, size);
+
+  if (buffer == NULL)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  return SYSRESULT (proc_env_set (proc, key, buffer, size));
+}
+
+/* int env_get (char* key, void* buffer, size_t size) */
+DEFINE_SYSCALL (sys_env_get) {
+  uint64_t fp, fpg;
+
+  uintptr_t uvaddr_key = a1;
+  uintptr_t uvaddr_buffer = a2;
+  size_t size = (size_t)a3;
+
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  uintptr_t out_paddr;
+
+  spin_lock (&proc->lock, &fp);
+  struct procgroup* procgroup = proc->procgroup;
+  spin_unlock (&proc->lock, fp);
+
+  spin_lock (&procgroup->lock, &fpg);
+
+  out_paddr = mm_v2p (&procgroup->pd, uvaddr_key);
+
+  if (out_paddr == 0) {
+    spin_unlock (&procgroup->lock, fpg);
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+  }
+
+  const char* key = (const char*)((uintptr_t)hhdm->offset + out_paddr);
+
+  spin_unlock (&procgroup->lock, fpg);
+
+  void* buffer = sys_get_user_buffer (procgroup, uvaddr_buffer, size);
+
+  if (buffer == NULL)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  return SYSRESULT (proc_env_set (proc, key, buffer, size));
+}
+
 static syscall_handler_func_t handler_table[] = {
     [SYS_QUIT] = &sys_quit,
     [SYS_TEST] = &sys_test,
@@ -857,6 +931,8 @@ static syscall_handler_func_t handler_table[] = {
     [SYS_CREATE_DIR] = &sys_create_dir,
     [SYS_REMOVE] = &sys_remove,
     [SYS_CREATE_VOLUME] = &sys_create_volume,
+    [SYS_ENV_SET] = &sys_env_set,
+    [SYS_ENV_GET] = &sys_env_get,
 };
 
 syscall_handler_func_t syscall_find_handler (int syscall_num) {