libaquarium: Functions for reading drives

src/lib/drive.c

@@ -0,0 +1,186 @@
+// #include <aquarium.h>
+#include "../aquarium.h"
+#include <err.h>
+#include <errno.h>
+#include <libgeom.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/queue.h>
+
+static aquarium_drive_kind_t drive_kind(char const* provider) {
+	// not super super robust but whatever
+
+	if (!strncmp(provider, "md", 2)) return AQUARIUM_DRIVE_KIND_MD;
+	if (!strncmp(provider, "ad", 2)) return AQUARIUM_DRIVE_KIND_ADA;
+	if (!strncmp(provider, "da", 2)) return AQUARIUM_DRIVE_KIND_DA;
+	if (!strncmp(provider, "nv", 2)) return AQUARIUM_DRIVE_KIND_NVME;
+	if (!strncmp(provider, "cd", 2)) return AQUARIUM_DRIVE_KIND_CD;
+
+	return AQUARIUM_DRIVE_KIND_OTHER;
+}
+
+static int process_drive(aquarium_drive_t** drives_ref, size_t* drives_len_ref, struct ggeom* geom, struct gclass* class) {
+	aquarium_drive_t* drives = *drives_ref;
+	size_t drives_len = *drives_len_ref;
+
+	if (LIST_EMPTY(&geom->lg_provider)) {
+		return 0;
+	}
+
+	// find provider(s)
+
+	struct gprovider* provider;
+
+	LIST_FOREACH(provider, &geom->lg_provider, lg_provider) {
+		drives = realloc(drives, ++drives_len * sizeof *drives);
+		aquarium_drive_t* const drive = &drives[drives_len - 1];
+
+		memset(drive, 0, sizeof *drive); // 'realloc' doesn't zero out anything unfortunately
+		drive->kind = drive_kind(provider->lg_name);
+
+		drive->provider = strdup(provider->lg_name); // TODO vs 'geom->lg_name'?
+		drive->rank = geom->lg_rank;
+
+		drive->sector_size = provider->lg_sectorsize;
+		drive->size = provider->lg_mediasize;
+
+		// find extra information on drive
+
+		struct gconfig* config;
+
+		LIST_FOREACH(config, &provider->lg_config, lg_config) {
+			if (!strcmp(config->lg_name, "ident") && config->lg_val) {
+				drive->ident = strdup(config->lg_val);
+			}
+
+			else if (!strcmp(config->lg_name, "descr") && config->lg_val) {
+				drive->name = strdup(config->lg_val);
+			}
+
+			else if (!strcmp(config->lg_name, "label") && config->lg_val) {
+				drive->label = strdup(config->lg_val);
+			}
+		}
+	}
+
+	// find potential label(s)
+
+	struct ggeom* label_geom;
+
+	LIST_FOREACH(label_geom, &class->lg_geom, lg_geom) {
+		if (strcmp(label_geom->lg_name, geom->lg_name)) {
+			continue;
+		}
+
+		// 'provider' already defined previously
+
+		LIST_FOREACH(provider, &label_geom->lg_provider, lg_provider) {
+			for (size_t i = 0; i < drives_len; i++) {
+				aquarium_drive_t* drive = &drives[i];
+
+				if (strcmp(drive->provider, provider->lg_name)) {
+					continue;
+				}
+
+				drive->label = strdup(provider->lg_name);
+				break;
+			}
+		}
+
+		break;
+	}
+
+	// set references
+
+	*drives_ref = drives;
+	*drives_len_ref = drives_len;
+
+	return 0;
+}
+
+static void free_drive(aquarium_drive_t* drive) {
+	if (drive->provider) {
+		free(drive->provider);
+	}
+
+	if (drive->ident) {
+		free(drive->ident);
+	}
+
+	if (drive->name) {
+		free(drive->name);
+	}
+
+	if (drive->label) {
+		free(drive->label);
+	}
+}
+
+static int process_class(aquarium_drive_t** drives_ref, size_t* drives_len_ref, struct gmesh* mesh, char const* name) {
+	struct gclass* class;
+
+	// find class we're interested in
+
+	LIST_FOREACH(class, &mesh->lg_class, lg_class) {
+		if (!strcmp(class->lg_name, name)) {
+			break;
+		}
+	}
+
+	if (!class) {
+		warnx("Failed to find '%s' class\n", name);
+		return -1;
+	}
+
+	// traverse through first layer of disk geometry (rank 1)
+
+	struct ggeom* geom;
+
+	LIST_FOREACH(geom, &class->lg_geom, lg_geom) {
+		process_drive(drives_ref, drives_len_ref, geom, class);
+	}
+
+	return 0;
+}
+
+int aquarium_read_drives(aquarium_drive_t** drives_ref, size_t* drives_len_ref) {
+	int rv = -1;
+
+	// get drive geometry mesh
+
+	struct gmesh mesh;
+
+	if (geom_gettree(&mesh) < 0) {
+		warnx("geom_gettree: %s\n", strerror(errno));
+		goto err_gettree;
+	}
+
+	if (
+		process_class(drives_ref, drives_len_ref, &mesh, "DISK" ) < 0 ||
+		process_class(drives_ref, drives_len_ref, &mesh, "MD"   ) < 0 ||
+		process_class(drives_ref, drives_len_ref, &mesh, "LABEL") < 0
+	) {
+		goto class_err;
+	}
+
+	// success
+
+	rv = 0;
+
+class_err:
+
+	geom_deletetree(&mesh);
+
+err_gettree:
+
+	return rv;
+}
+
+void aquarium_free_drives(aquarium_drive_t* drives, size_t drives_len) {
+	for (size_t i = 0; i < drives_len; i++) {
+		aquarium_drive_t* const drive = &drives[i];
+		free_drive(drive);
+	}
+
+	free(drives);
+}