1 files changed, 87 insertions, 0 deletions
diff --git a/frida_mode/src/shm.c b/frida_mode/src/shm.c
new file mode 100644
index 00000000..282526e8
--- /dev/null
+++ b/frida_mode/src/shm.c
@@ -0,0 +1,87 @@
+#include "shm.h"
+#include "util.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/ipc.h>
+#include <sys/mman.h>
+#include <sys/shm.h>
+#ifdef __ANDROID__
+  #include <linux/ashmem.h>
+  #include <sys/ioctl.h>
+#endif
+
+#ifdef __ANDROID__
+  #define ASHMEM_DEVICE "/dev/ashmem"
+
+void *shm_create(size_t size) {
+
+  int               fd = -1;
+  char              ourkey[11] = {0};
+  void             *addr = MAP_FAILED;
+  struct ashmem_pin pin = {0, size};
+
+  fd = open(ASHMEM_DEVICE, O_RDWR);
+  if (fd < 0) { FFATAL("Failed open /dev/ashmem: %d", errno); }
+
+  if (snprintf(ourkey, sizeof(ourkey) - 1, "%d", IPC_PRIVATE) < 0) {
+
+    FFATAL("Failed to generate key: %d", errno);
+
+  }
+
+  if (ioctl(fd, ASHMEM_SET_NAME, ourkey) < 0) {
+
+    FFATAL("ioctl(ASHMEM_SET_NAME) errno: %d\n", errno);
+
+  }
+
+  if (ioctl(fd, ASHMEM_SET_SIZE, size) < 0) {
+
+    FFATAL("ioctl(ASHMEM_SET_SIZE) errno: %d\n", errno);
+
+  }
+
+  addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+  if (addr == MAP_FAILED) { FFATAL("mmap failed: %d\n", errno); }
+
+  /* Shared memory pinning has been deprecated. So if the ioctl fails, then
+  just assume we are running on a version where it has been. Worst case, we
+  will leak the shared memory region.*/
+  ioctl(fd, ASHMEM_UNPIN, &pin);
+  close(fd);
+
+  return addr;
+
+}
+
+#else
+void *shm_create(size_t size) {
+
+  int shm_id =
+      shmget(IPC_PRIVATE, size, IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR);
+  if (shm_id < 0) { FFATAL("shm_id < 0 - errno: %d\n", errno); }
+
+  void *addr = shmat(shm_id, NULL, 0);
+  if (addr == MAP_FAILED) { FFATAL("addr == MAP_FAILED - errno: %d\n", errno); }
+
+  /*
+   * Configure the shared memory region to be removed once the process
+   * dies.
+   */
+  if (shmctl(shm_id, IPC_RMID, NULL) < 0) {
+
+    FFATAL("shmctl (IPC_RMID) < 0 - errno: %d\n", errno);
+
+  }
+
+  /* Clear it, not sure it's necessary, just seems like good practice */
+  memset(addr, '\0', size);
+
+  return addr;
+
+}
+
+#endif
+