Remove lockdown gnutls buffer hack [#1 state:resolved]

Signed-off-by: Matt Colyer <matt@colyer.name>

2 files changed, 42 insertions, 66 deletions

diff --git a/src/lockdown.c b/src/lockdown.c
index 2d85a03..73a8bbc 100644
--- a/src/lockdown.c
+++ b/src/lockdown.c
@@ -88,7 +88,6 @@ iphone_lckd_client_t new_lockdownd_client(iphone_device_t phone)
 
         control->ssl_session = (gnutls_session_t *) malloc(sizeof(gnutls_session_t));
         control->in_SSL = 0;
-        control->gtls_buffer_hack_len = 0;
         return control;
 }
 
@@ -179,7 +178,6 @@ static void iphone_lckd_stop_SSL_session(iphone_lckd_client_t client)
                 free(client->ssl_session);
         }
         client->in_SSL = 0;
-        client->gtls_buffer_hack_len = 0;       // dunno if required?!
 
         return;
 }
@@ -459,6 +457,10 @@ iphone_error_t iphone_lckd_new_client(iphone_device_t device, iphone_lckd_client
         char *host_id = NULL;
 
         iphone_lckd_client_t client_loc = new_lockdownd_client(device);
+        if (!client_loc) {
+                log_debug_msg("FATAL: lockdownd client could not be created!\n");
+                return IPHONE_E_UNKNOWN_ERROR;
+        }
         if (IPHONE_E_SUCCESS != lockdownd_hello(client_loc)) {
                 log_debug_msg("Hello failed in the lockdownd client.\n");
                 ret = IPHONE_E_NOT_ENOUGH_DATA;
@@ -969,77 +971,53 @@ ssize_t lockdownd_secuwrite(gnutls_transport_ptr_t transport, char *buffer, size
 ssize_t lockdownd_securead(gnutls_transport_ptr_t transport, char *buffer, size_t length)
 {
         int bytes = 0, pos_start_fill = 0;
-        char *hackhackhack = NULL;
+        int tbytes = 0;
+        int this_len = length;
+        iphone_error_t res;
         iphone_lckd_client_t control;
         control = (iphone_lckd_client_t) transport;
+        char *recv_buffer;
+
         log_debug_msg("lockdownd_securead() called\nlength = %zi\n", length);
-        // Buffering hack! Throw what we've got in our "buffer" into the stream first, then get more.
-        if (control->gtls_buffer_hack_len > 0) {
-                if (length > control->gtls_buffer_hack_len) {   // If it's asking for more than we got
-                        length -= control->gtls_buffer_hack_len;        // Subtract what we have from their requested length
-                        pos_start_fill = control->gtls_buffer_hack_len; // set the pos to start filling at
-                        memcpy(buffer, control->gtls_buffer_hack, control->gtls_buffer_hack_len);       // Fill their buffer partially
-                        free(control->gtls_buffer_hack);        // free our memory, it's not chained anymore
-                        control->gtls_buffer_hack_len = 0;      // we don't have a hack buffer anymore
-                        log_debug_msg("Did a partial fill to help quench thirst for data\n");
-                } else if (length < control->gtls_buffer_hack_len) {    // If it's asking for less...
-                        control->gtls_buffer_hack_len -= length;        // subtract what they're asking for
-                        memcpy(buffer, control->gtls_buffer_hack, length);      // fill their buffer
-                        hackhackhack = (char *) malloc(sizeof(char) * control->gtls_buffer_hack_len);   // strndup is NOT a good solution -- concatenates \0!!!! Anyway, make a new "hack" buffer.
-                        memcpy(hackhackhack, control->gtls_buffer_hack + length, control->gtls_buffer_hack_len);        // Move what's left into the new one
-                        free(control->gtls_buffer_hack);        // Free the old one
-                        control->gtls_buffer_hack = hackhackhack;       // And make it the new one.
-                        hackhackhack = NULL;
-                        log_debug_msg("Quenched the thirst for data; new hack length is %i\n", control->gtls_buffer_hack_len);
-                        return length;          // hand it over.
-                } else {                                // length == hack length
-                        memcpy(buffer, control->gtls_buffer_hack, length);      // copy our buffer into theirs
-                        free(control->gtls_buffer_hack);        // free our "obligation"
-                        control->gtls_buffer_hack_len = 0;      // free our "obligation"
-                        log_debug_msg("Satiated the thirst for data; now we have to eventually receive again.\n");
-                        return length;          // hand it over
-                }
-        }
-        // End buffering hack!
-        char *recv_buffer = (char *) malloc(sizeof(char) * (length * 1000));    // ensuring nothing stupid happens
 
         log_debug_msg("pre-read\nclient wants %zi bytes\n", length);
-        iphone_mux_recv(control->connection, recv_buffer, (length * 1000), &bytes);
-        log_debug_msg("post-read\nwe got %i bytes\n", bytes);
-        if (bytes < 0) {
-                log_debug_msg("lockdownd_securead(): uh oh\n");
-                log_debug_msg
-                        ("I believe what we have here is a failure to communicate... libusb says %s but strerror says %s\n",
-                         usb_strerror(), strerror(errno));
-                return bytes + 28;              // an errno
-        }
-        if (bytes >= length) {
-                if (bytes > length) {
+
+        recv_buffer = (char *) malloc(sizeof(char) * this_len);
+
+        // repeat until we have the full data or an error occurs.
+        do {
+                if ((res = iphone_mux_recv(control->connection, recv_buffer, this_len, &bytes)) != IPHONE_E_SUCCESS) {
+                        log_debug_msg("%s: ERROR: iphone_mux_recv returned %d\n", __func__, res);
+                        return res;
+                }
+                log_debug_msg("post-read\nwe got %i bytes\n", bytes);
+
+                if (bytes < 0) {
+                        log_debug_msg("lockdownd_securead(): uh oh\n");
                         log_debug_msg
-                                ("lockdownd_securead: Client deliberately read less data than was there; resorting to GnuTLS buffering hack.\n");
-                        if (!control->gtls_buffer_hack_len) {   // if there's no hack buffer yet
-                                //control->gtls_buffer_hack = strndup(recv_buffer+length, bytes-length); // strndup is NOT a good solution!
-                                control->gtls_buffer_hack_len += bytes - length;
-                                control->gtls_buffer_hack = (char *) malloc(sizeof(char) * control->gtls_buffer_hack_len);
-                                memcpy(control->gtls_buffer_hack, recv_buffer + length, control->gtls_buffer_hack_len);
-                        } else {                        // if there is. 
-                                control->gtls_buffer_hack =
-                                        realloc(control->gtls_buffer_hack, control->gtls_buffer_hack_len + (bytes - length));
-                                memcpy(control->gtls_buffer_hack + control->gtls_buffer_hack_len, recv_buffer + length, bytes - length);
-                                control->gtls_buffer_hack_len += bytes - length;
-                        }
+                                ("I believe what we have here is a failure to communicate... libusb says %s but strerror says %s\n",
+                                 usb_strerror(), strerror(errno));
+                        return bytes;           // + 28;      // an errno
                 }
-                memcpy(buffer + pos_start_fill, recv_buffer, length);
-                free(recv_buffer);
-                if (bytes == length) {
-                        log_debug_msg("Returning how much we received.\n");
-                        return bytes;
-                } else {
-                        log_debug_msg("Returning what they want to hear.\nHack length: %i\n", control->gtls_buffer_hack_len);
-                        return length;
+                // increase read count
+                tbytes += bytes;
+
+                // fill the buffer with what we got right now
+                memcpy(buffer + pos_start_fill, recv_buffer, bytes);
+                pos_start_fill += bytes;
+
+                if (tbytes >= length) {
+                        break;
                 }
+
+                this_len = length - tbytes;
+                log_debug_msg("re-read\ntrying to read missing %i bytes\n", this_len);
+        } while (tbytes < length);
+        if (recv_buffer) {
+                free(recv_buffer);
         }
-        return bytes;
+
+        return tbytes;
 }
 
 /** Command to start the desired service
diff --git a/src/lockdown.h b/src/lockdown.h
index 91bcc77..c30a182 100644
--- a/src/lockdown.h
+++ b/src/lockdown.h
@@ -36,8 +36,6 @@ struct iphone_lckd_client_int {
         iphone_umux_client_t connection;
         gnutls_session_t *ssl_session;
         int in_SSL;
-        char *gtls_buffer_hack;
-        int gtls_buffer_hack_len;
         char session_id[40];
 };