Add backend for Garmin Descent Mk1

This uses pretty much all of our new infrastructure: the USB storage
iostream for the actual IO, the field-cache for the divecomputer fields,
and the string interface for the events.

It's also a very fast downloader.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

examples/common.c

@@ -90,6 +90,7 @@ static const backend_table_t g_backends[] = {
 	{"idive",       DC_FAMILY_DIVESYSTEM_IDIVE,    0x03},
 	{"cochran",     DC_FAMILY_COCHRAN_COMMANDER,   0},
 	{"divecomputereu", DC_FAMILY_TECDIVING_DIVECOMPUTEREU, 0},
+	{"descentmk1",  DC_FAMILY_GARMIN, 0},
 };
 
 static const transport_table_t g_transports[] = {

include/libdivecomputer/common.h

@@ -108,6 +108,8 @@ typedef enum dc_family_t {
 	DC_FAMILY_COCHRAN_COMMANDER = (14 << 16),
 	/* Tecdiving */
 	DC_FAMILY_TECDIVING_DIVECOMPUTEREU = (15 << 16),
+	/* Garmin */
+	DC_FAMILY_GARMIN = (16 << 16),
 } dc_family_t;
 
 #ifdef __cplusplus

msvc/libdivecomputer.vcproj

@@ -498,6 +498,14 @@
 				RelativePath="..\src\tecdiving_divecomputereu_parser.c"
 				>
 			</File>
+			<File
+				RelativePath="..\src\garmin.c"
+				>
+			</File>
+			<File
+				RelativePath="..\src\garmin_parser.c"
+				>
+			</File>
 			<File
 				RelativePath="..\src\field-cache.c"
 				>
@@ -844,6 +852,10 @@
 				RelativePath="..\src\tecdiving_divecomputereu.h"
 				>
 			</File>
+			<File
+				RelativePath="..\src\garmin.h"
+				>
+			</File>
 			<File
 				RelativePath="..\src\timer.h"
 				>

src/Makefile.am

@@ -73,6 +73,7 @@ libdivecomputer_la_SOURCES = \
 	buffer.c \
 	cochran_commander.h cochran_commander.c cochran_commander_parser.c \
 	tecdiving_divecomputereu.h tecdiving_divecomputereu.c tecdiving_divecomputereu_parser.c \
+	garmin.h garmin.c garmin_parser.c \
 	socket.h socket.c \
 	irda.c \
 	usbhid.c \

src/descriptor.c

@@ -45,6 +45,7 @@ static int dc_filter_suunto (dc_transport_t transport, const void *userdata);
 static int dc_filter_shearwater (dc_transport_t transport, const void *userdata);
 static int dc_filter_hw (dc_transport_t transport, const void *userdata);
 static int dc_filter_tecdiving (dc_transport_t transport, const void *userdata);
+static int dc_filter_garmin (dc_transport_t transport, const void *userdata);
 static int dc_filter_mares (dc_transport_t transport, const void *userdata);
 static int dc_filter_divesystem (dc_transport_t transport, const void *userdata);
 static int dc_filter_oceanic (dc_transport_t transport, const void *userdata);
@@ -376,6 +377,8 @@ static const dc_descriptor_t g_descriptors[] = {
 	{"Cochran", "EMC-20H",      DC_FAMILY_COCHRAN_COMMANDER, 5, DC_TRANSPORT_SERIAL, NULL},
 	/* Tecdiving DiveComputer.eu */
 	{"Tecdiving", "DiveComputer.eu", DC_FAMILY_TECDIVING_DIVECOMPUTEREU, 0, DC_TRANSPORT_SERIAL | DC_TRANSPORT_BLUETOOTH, dc_filter_tecdiving},
+	/* Garmin */
+	{"Garmin", "Descent Mk1", DC_FAMILY_GARMIN, 2859, DC_TRANSPORT_USBSTORAGE, dc_filter_garmin},
 };
 
 static int
@@ -581,6 +584,19 @@ static int dc_filter_tecdiving (dc_transport_t transport, const void *userdata)
 	return 1;
 }
 
+static int dc_filter_garmin (dc_transport_t transport, const void *userdata)
+{
+	static const dc_usb_desc_t usbhid[] = {
+		{0x091e, 0x2b2b}, // Garmin Descent Mk1
+	};
+
+	if (transport == DC_TRANSPORT_USBSTORAGE) {
+		return DC_FILTER_INTERNAL (userdata, usbhid, 0, dc_match_usb);
+	}
+
+	return 1;
+}
+
 static int dc_filter_mares (dc_transport_t transport, const void *userdata)
 {
 	static const char * const bluetooth[] = {

src/device.c

@@ -57,6 +57,7 @@
 #include "divesystem_idive.h"
 #include "cochran_commander.h"
 #include "tecdiving_divecomputereu.h"
+#include "garmin.h"
 
 #include "device-private.h"
 #include "context-private.h"
@@ -211,6 +212,9 @@ dc_device_open (dc_device_t **out, dc_context_t *context, dc_descriptor_t *descr
 	case DC_FAMILY_TECDIVING_DIVECOMPUTEREU:
 		rc = tecdiving_divecomputereu_device_open (&device, context, iostream);
 		break;
+	case DC_FAMILY_GARMIN:
+		rc = garmin_device_open (&device, context, iostream);
+		break;
 	default:
 		return DC_STATUS_INVALIDARGS;
 	}

src/garmin.c

@@ -0,0 +1,338 @@
+/*
+ * Garmin Descent Mk1 USB storage downloading
+ *
+ * Copyright (C) 2018 Linus Torvalds
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "garmin.h"
+#include "context-private.h"
+#include "device-private.h"
+#include "array.h"
+
+typedef struct garmin_device_t {
+	dc_device_t base;
+	dc_iostream_t *iostream;
+	unsigned char fingerprint[FIT_NAME_SIZE];
+} garmin_device_t;
+
+static dc_status_t garmin_device_set_fingerprint (dc_device_t *abstract, const unsigned char data[], unsigned int size);
+static dc_status_t garmin_device_foreach (dc_device_t *abstract, dc_dive_callback_t callback, void *userdata);
+static dc_status_t garmin_device_close (dc_device_t *abstract);
+
+static const dc_device_vtable_t garmin_device_vtable = {
+	sizeof(garmin_device_t),
+	DC_FAMILY_GARMIN,
+	garmin_device_set_fingerprint, /* set_fingerprint */
+	NULL, /* read */
+	NULL, /* write */
+	NULL, /* dump */
+	garmin_device_foreach, /* foreach */
+	NULL, /* timesync */
+	garmin_device_close, /* close */
+};
+
+dc_status_t
+garmin_device_open (dc_device_t **out, dc_context_t *context, dc_iostream_t *iostream)
+{
+	dc_status_t status = DC_STATUS_SUCCESS;
+	garmin_device_t *device = NULL;
+
+	if (out == NULL)
+		return DC_STATUS_INVALIDARGS;
+
+	// Allocate memory.
+	device = (garmin_device_t *) dc_device_allocate (context, &garmin_device_vtable);
+	if (device == NULL) {
+		ERROR (context, "Failed to allocate memory.");
+		return DC_STATUS_NOMEMORY;
+	}
+
+	// Set the default values.
+	device->iostream = iostream;
+	memset(device->fingerprint, 0, sizeof(device->fingerprint));
+
+	*out = (dc_device_t *) device;
+
+	return DC_STATUS_SUCCESS;
+}
+
+static dc_status_t
+garmin_device_set_fingerprint (dc_device_t *abstract, const unsigned char data[], unsigned int size)
+{
+	garmin_device_t *device = (garmin_device_t *)abstract;
+
+	if (size && size != sizeof (device->fingerprint))
+		return DC_STATUS_INVALIDARGS;
+
+	if (size)
+		memcpy (device->fingerprint, data, sizeof (device->fingerprint));
+	else
+		memset (device->fingerprint, 0, sizeof (device->fingerprint));
+
+	return DC_STATUS_SUCCESS;
+}
+
+
+static dc_status_t
+garmin_device_close (dc_device_t *abstract)
+{
+	dc_status_t status = DC_STATUS_SUCCESS;
+	garmin_device_t *device = (garmin_device_t *) abstract;
+
+	return DC_STATUS_SUCCESS;
+}
+
+struct file_list {
+	int nr, allocated;
+	struct fit_name *array;
+};
+
+static int name_cmp(const void *a, const void *b)
+{
+	// Sort reverse string ordering (newest first), so use 'b,a'
+	return strcmp(b,a);
+}
+
+/*
+ * Get the FIT file list and sort it.
+ *
+ * Return number of files found.
+*/
+static int get_file_list(dc_device_t *abstract, DIR *dir, struct file_list *files)
+{
+	struct dirent *de;
+
+	DEBUG (abstract->context, "Iterating over Garmin files");
+	while ((de = readdir(dir)) != NULL) {
+		int len = strlen(de->d_name);
+		struct fit_name *entry;
+		const char *explain = NULL;
+
+		DEBUG (abstract->context, "  %s", de->d_name);
+
+		if (len < 5)
+			explain = "name too short";
+		if (len >= FIT_NAME_SIZE)
+			explain = "name too long";
+		if (strncasecmp(de->d_name + len - 4, ".FIT", 4))
+			explain = "name lacks FIT suffix";
+
+		DEBUG (abstract->context, "  %s - %s", de->d_name, explain ? explain : "adding to list");
+		if (explain)
+			continue;
+
+		if (files->nr == files->allocated) {
+			struct fit_name *array;
+			int n = 3*(files->allocated + 8)/2;
+			size_t new_size;
+
+			new_size = n * sizeof(array[0]);
+			array = realloc(files->array, new_size);
+			if (!array)
+				return DC_STATUS_NOMEMORY;
+
+			files->array = array;
+			files->allocated = n;
+		}
+
+		/*
+		 * NOTE! This depends on the zero-padding that strncpy does.
+		 *
+		 * strncpy() doesn't just limit the size of the copy, it
+		 * will zero-pad the end of the result buffer.
+		 */
+		entry = files->array + files->nr++;
+		strncpy(entry->name, de->d_name, FIT_NAME_SIZE);
+	}
+	DEBUG (abstract->context, "Found %d files", files->nr);
+
+	qsort(files->array, files->nr, sizeof(struct fit_name), name_cmp);
+	return DC_STATUS_SUCCESS;
+}
+
+#ifndef O_BINARY
+#define O_BINARY 0
+#endif
+
+static dc_status_t
+read_file(char *pathname, int pathlen, const char *name, dc_buffer_t *file)
+{
+	int fd, rc;
+
+	pathname[pathlen] = '/';
+	memcpy(pathname+pathlen+1, name, FIT_NAME_SIZE);
+	fd = open(pathname, O_RDONLY | O_BINARY);
+
+	if (fd < 0)
+		return DC_STATUS_IO;
+
+	rc = DC_STATUS_SUCCESS;
+	for (;;) {
+		char buffer[4096];
+		int n;
+
+		n = read(fd, buffer, sizeof(buffer));
+		if (!n)
+			break;
+		if (n > 0) {
+			dc_buffer_append(file, buffer, n);
+			continue;
+		}
+		rc = DC_STATUS_IO;
+		break;
+	}
+
+	close(fd);
+	return rc;
+}
+
+static dc_status_t
+garmin_device_foreach (dc_device_t *abstract, dc_dive_callback_t callback, void *userdata)
+{
+	dc_status_t status = DC_STATUS_SUCCESS;
+	garmin_device_t *device = (garmin_device_t *) abstract;
+	dc_parser_t *parser;
+	char pathname[PATH_MAX];
+	size_t pathlen;
+	struct file_list files = { 0, 0, NULL };
+	dc_buffer_t *file;
+	DIR *dir;
+	int rc;
+
+	// Read the directory name from the iostream
+	rc = dc_iostream_read(device->iostream, &pathname, sizeof(pathname)-1, &pathlen);
+	if (rc != DC_STATUS_SUCCESS)
+		return rc;
+	pathname[pathlen] = 0;
+
+	// The actual dives are under the "Garmin/Activity/" directory
+	// as FIT files, with names like "2018-08-20-10-23-30.fit".
+	// Make sure our buffer is big enough.
+	if (pathlen + strlen("/Garmin/Activity/") + FIT_NAME_SIZE + 2 > PATH_MAX) {
+		ERROR (abstract->context, "Invalid Garmin base directory '%s'", pathname);
+		return DC_STATUS_IO;
+	}
+
+	if (pathlen && pathname[pathlen-1] != '/')
+		pathname[pathlen++] = '/';
+	strcpy(pathname + pathlen, "Garmin/Activity");
+	pathlen += strlen("Garmin/Activity");
+
+	dir = opendir(pathname);
+	if (!dir) {
+		ERROR (abstract->context, "Failed to open directory '%s'.", pathname);
+		return DC_STATUS_IO;
+	}
+
+	// Get the list of FIT files
+	rc = get_file_list(abstract, dir, &files);
+	closedir(dir);
+	if (rc != DC_STATUS_SUCCESS || !files.nr) {
+		free(files.array);
+		return rc;
+	}
+
+	// Can we find the fingerprint entry?
+	for (int i = 0; i < files.nr; i++) {
+		const char *name = files.array[i].name;
+
+		if (memcmp(name, device->fingerprint, sizeof (device->fingerprint)))
+			continue;
+
+		// Found fingerprint, just cut the array short here
+		files.nr = i;
+		DEBUG (abstract->context, "Ignoring '%s' and older", name);
+		break;
+	}
+
+	// Enable progress notifications.
+	dc_event_progress_t progress = EVENT_PROGRESS_INITIALIZER;
+	progress.maximum = files.nr;
+	progress.current = 0;
+	device_event_emit (abstract, DC_EVENT_PROGRESS, &progress);
+
+	file = dc_buffer_new (16384);
+	if (file == NULL) {
+		ERROR (abstract->context, "Insufficient buffer space available.");
+		free(files.array);
+		return DC_STATUS_NOMEMORY;
+	}
+	if ((rc = garmin_parser_create(&parser, abstract->context) != DC_STATUS_SUCCESS)) {
+		ERROR (abstract->context, "Failed to create parser for dive verification.");
+		free(files.array);
+		return rc;
+	}
+
+	dc_event_devinfo_t devinfo;
+	dc_event_devinfo_t *devinfo_p = &devinfo;
+	for (int i = 0; i < files.nr; i++) {
+		const char *name = files.array[i].name;
+		const unsigned char *data;
+		unsigned int size;
+		short is_dive = 0;
+
+		if (device_is_cancelled(abstract)) {
+			status = DC_STATUS_CANCELLED;
+			break;
+		}
+
+		// Reset the membuffer, read the data
+		dc_buffer_clear(file);
+		dc_buffer_append(file, name, FIT_NAME_SIZE);
+
+		status = read_file(pathname, pathlen, name, file);
+		if (status != DC_STATUS_SUCCESS)
+			break;
+
+		data = dc_buffer_get_data(file);
+		size = dc_buffer_get_size(file);
+
+		is_dive = garmin_parser_is_dive(parser, data, size, devinfo_p);
+		if (devinfo_p) {
+			// first time we came through here, let's emit the
+			// devinfo and vendor events
+			device_event_emit (abstract, DC_EVENT_DEVINFO, devinfo_p);
+			devinfo_p = NULL;
+		}
+		if (!is_dive) {
+			DEBUG (abstract->context, "decided %s isn't a dive.", name);
+			continue;
+		}
+
+		if (callback && !callback(data, size, name, FIT_NAME_SIZE, userdata))
+			break;
+
+		progress.current++;
+		device_event_emit(abstract, DC_EVENT_PROGRESS, &progress);
+	}
+
+	free(files.array);
+	dc_parser_destroy(parser);
+	return status;
+}

src/garmin.h

@@ -0,0 +1,59 @@
+/*
+ * Garmin Descent Mk1
+ *
+ * Copyright (C) 2018 Linus Torvalds
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#ifndef GARMIN_H
+#define GARMIN_H
+
+#include <libdivecomputer/context.h>
+#include <libdivecomputer/iostream.h>
+#include <libdivecomputer/device.h>
+#include <libdivecomputer/parser.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+dc_status_t
+garmin_device_open (dc_device_t **device, dc_context_t *context, dc_iostream_t *iostream);
+
+dc_status_t
+garmin_parser_create (dc_parser_t **parser, dc_context_t *context);
+
+// we need to be able to call into the parser to check if the
+// files that we find are actual dives
+int
+garmin_parser_is_dive (dc_parser_t *abstract, const unsigned char *data, unsigned int size, dc_event_devinfo_t *devinfo_p);
+
+// The dive names are of the form "2018-08-20-10-23-30.fit"
+// With the terminating zero, that's 24 bytes.
+//
+// We use this as the fingerprint, but it ends up being a
+// special fixed header in the parser data too.
+#define FIT_NAME_SIZE 24
+
+struct fit_name {
+	char name[FIT_NAME_SIZE];
+};
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* GARMIN_H */

src/parser.c

@@ -57,6 +57,7 @@
 #include "divesystem_idive.h"
 #include "cochran_commander.h"
 #include "tecdiving_divecomputereu.h"
+#include "garmin.h"
 
 #include "context-private.h"
 #include "parser-private.h"
@@ -172,6 +173,9 @@ dc_parser_new_internal (dc_parser_t **out, dc_context_t *context, dc_family_t fa
 	case DC_FAMILY_TECDIVING_DIVECOMPUTEREU:
 		rc = tecdiving_divecomputereu_parser_create (&parser, context);
 		break;
+	case DC_FAMILY_GARMIN:
+		rc = garmin_parser_create (&parser, context);
+		break;
 	default:
 		return DC_STATUS_INVALIDARGS;
 	}