1 files changed, 123 insertions, 0 deletions
diff --git a/userland/sftp/handle.c b/userland/sftp/handle.c
new file mode 100644
index 0000000..44901ea
--- /dev/null
+++ b/userland/sftp/handle.c
@@ -0,0 +1,123 @@
+#include "handle.h"
+#include <assert.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/random.h>
+#include <unistd.h>
+
+struct handle {
+  int fd;
+  char *key;
+  char *pathname;
+  struct handle *next;
+  struct handle *prev;
+};
+
+struct handle *head = NULL;
+
+char *generate_random_key(int length) {
+  assert(length < 256);
+  char buf[256];
+
+  randomfill(buf, 256);
+  //  assert(0 == getentropy(buf, 256));
+  char *r = malloc(length + 1);
+  if (!r) {
+    return NULL;
+  }
+  for (int i = 0; i < length; i++) {
+    r[i] = 'A' + (buf[i] & 0xF);
+  }
+  r[length] = '\0';
+  return r;
+}
+
+static struct handle *handle_get(struct sv key) {
+  struct handle *p = head;
+  for (; p; p = p->next) {
+    if (!sv_eq(C_TO_SV(p->key), key)) {
+      continue;
+    }
+    return p;
+  }
+  return NULL;
+}
+
+int handle_get_fd(struct sv key, int *fd, char **pathname) {
+  struct handle *h = handle_get(key);
+  if (!h) {
+    return 0;
+  }
+  if (fd) {
+    *fd = h->fd;
+  }
+  if (pathname) {
+    *pathname = h->pathname;
+  }
+  return 1;
+}
+
+char *handle_create(struct sv path, int is_dir, int flags, int mode) {
+  int f;
+  if (is_dir) {
+    //    f = O_DIRECTORY | O_RDONLY;
+    f = O_RDONLY;
+  } else {
+    f = flags;
+  }
+  char *p = SV_TO_C(path);
+  int fd = open(p, f, mode);
+  if (-1 == fd) {
+    free(p);
+    return NULL;
+  }
+  free(p);
+
+  // 64 bits of entropy
+  char *key = generate_random_key(16);
+  if (!key) {
+    close(fd);
+    return NULL;
+  }
+
+  struct handle *n = malloc(sizeof(struct handle));
+  if (!n) {
+    free(key);
+    close(fd);
+    return NULL;
+  }
+  n->fd = fd;
+  n->key = key;
+  n->pathname = SV_TO_C(path);
+  n->next = head;
+  n->prev = NULL;
+  if (head) {
+    head->prev = n;
+  }
+  head = n;
+  return key;
+}
+
+int handle_close(struct sv key) {
+  struct handle *h = handle_get(key);
+  if (!h) {
+    return 0;
+  }
+
+  if (head == h) {
+    head = h->next;
+  }
+
+  if (h->prev) {
+    h->prev->next = h->next;
+  }
+  if (h->next) {
+    h->next->prev = h->prev;
+  }
+  free(h->key);
+  free(h->pathname);
+  free(h);
+  return 1;
+}