Fix host env import

Signed-off-by: Christoph M. Wintersteiger <[email protected]>

src/enclave/enclave_oe.c

@@ -57,7 +57,8 @@ static void _prepare_elf_stack()
  size_t num_imported_env = 0;
  const char** imported_env = NULL;
 
- if (sgxlkl_enclave_state.shared_memory.env && cfg->num_host_import_env > 0)
+ if (sgxlkl_enclave_state.shared_memory.env &&
+ sgxlkl_enclave_state.shared_memory.envc && cfg->num_host_import_env > 0)
  {
  imported_env = oe_calloc_or_die(
  cfg->num_host_import_env,
@@ -67,16 +68,12 @@ static void _prepare_elf_stack()
  for (size_t i = 0; i < cfg->num_host_import_env; i++)
  {
  const char* name = cfg->host_import_env[i];
- for (char* const* p = sgxlkl_enclave_state.shared_memory.env;
- p && *p != NULL;
- p++)
+ size_t n = oe_strlen(name);
+ for (size_t i = 0; i < sgxlkl_enclave_state.shared_memory.envc; i++)
  {
- size_t n = oe_strlen(name);
- if (_strncmp(name, *p, n) == 0 && (*p)[n] == '=')
- {
- const char* str = *p;
- imported_env[num_imported_env++] = str;
- }
+ const char* henv_i = sgxlkl_enclave_state.shared_memory.env[i];
+ if (_strncmp(name, henv_i, n) == 0 && henv_i[n] == '=')
+ imported_env[num_imported_env++] = henv_i;
  }
  }
  }
@@ -335,14 +332,12 @@ static void _copy_shared_memory(const sgxlkl_shared_memory_t* host)
 
  /* Copy the host's environment variables to enclave memory */
  char* const* henv = host->env;
- if (henv)
+ size_t henvc = host->envc;
+ if (henv && henvc)
  {
- size_t henvc = 0;
- while (henv[henvc] != 0)
- henvc++;
  CHECK_OUTSIDE(henv, sizeof(char*) * henvc);
  char** tmp = oe_calloc_or_die(
- henvc + 1,
+ henvc,
  sizeof(char*),
  "Could not allocate memory for host import environment variable\n");
  for (size_t i = 0; i < henvc; i++)
@@ -353,8 +348,9 @@ static void _copy_shared_memory(const sgxlkl_shared_memory_t* host)
  tmp[i] = oe_malloc(n);
  memcpy(tmp[i], env_i, n);
  }
- tmp[henvc] = NULL;
  enc->env = tmp;
+ enc->envc = henvc;
+ CHECK_INSIDE(enc->env, sizeof(char*) * enc->envc);
  }
 
  /* Commit to the temporary copy */
@@ -372,8 +368,9 @@ static void _free_shared_memory()
  oe_free(shm->virtio_blk_dev_mem);
  oe_free(shm->virtio_blk_dev_names);
 
- for (size_t i = 0; shm->env[i] != 0; i++)
- oe_free(shm->env[i]);
+ if (shm->env && shm->envc)
+ for (size_t i = 0; i < shm->envc; i++)
+ oe_free(shm->env[i]);
  oe_free((char**)shm->env);
 }
 

src/include/shared/shared_memory.h

@@ -29,6 +29,7 @@ typedef struct sgxlkl_shared_memory
 
  /* Host environment variables for optional import */
  char* const* env;
+ size_t envc;
 } sgxlkl_shared_memory_t;
 
 #endif /* SGXLKL_SHARED_MEMORY_H */

src/main-oe/sgxlkl_run_oe.c

@@ -1814,6 +1814,9 @@ int main(int argc, char* argv[], char* envp[])
 
  bool have_enclave_config_file = enclave_config_path != NULL;
  set_clock_res(have_enclave_config_file);
+ sgxlkl_host_state.shared_memory.envc = 0;
+ for (char** env = envp; *env != 0; env++)
+ sgxlkl_host_state.shared_memory.envc++;
  sgxlkl_host_state.shared_memory.env = envp;
  set_tls(have_enclave_config_file);
  register_hds(root_hd);

tests/basic/eeid-config/Makefile

@@ -6,7 +6,7 @@ IMAGE_SIZE=5M
 
 EXECUTION_TIMEOUT=60
 
-SGXLKL_ENV=SGXLKL_VERBOSE=1 SGXLKL_KERNEL_VERBOSE=1
+SGXLKL_ENV=SGXLKL_VERBOSE=1 SGXLKL_KERNEL_VERBOSE=1 HOSTNAME=EEIDHOST
 SGXLKL_HW_PARAMS=--hw-debug
 SGXLKL_SW_PARAMS=--sw-debug
 

tests/basic/eeid-config/hello-eeid.c

@@ -31,5 +31,16 @@ int main(int argc, char** argv)
  exit(1);
  }
 
+ // Application environment variable
+ const char* abc = getenv("ABC");
+ if (strcmp(abc, "DEF") != 0)
+ exit(1);
+
+ // Environment variable imported from host
+ const char* hostname = getenv("HOSTNAME");
+ printf("HOSTNAME=%s\n", hostname);
+ if (!hostname || strcmp(hostname, "EEIDHOST") != 0)
+ exit(1);
+
  return 0;
 }