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authorAmaury Pouly <amaury.pouly@gmail.com>2018-11-30 15:14:30 +0100
committerAmaury Pouly <amaury.pouly@gmail.com>2018-11-30 15:37:10 +0100
commite01248efcd622211c0451e6dc4ed47cc4b758cfa (patch)
treeba0d979d82579f67b75b074e38eeaf34b3599cfe /utils/scsi/rbscsi.c
parent43654371591feab23ce0a52af42bb88de0abfbca (diff)
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rbscsi: add experimental API to list connected SCSI devices
For now it is only implemented on linux using /sys scanning Change-Id: Ifdfe7564e6e8d0307ae6ddc53e49bb9aaf5a8268
Diffstat (limited to 'utils/scsi/rbscsi.c')
-rw-r--r--utils/scsi/rbscsi.c212
1 files changed, 211 insertions, 1 deletions
diff --git a/utils/scsi/rbscsi.c b/utils/scsi/rbscsi.c
index a43608a08b..8e15f1fd6a 100644
--- a/utils/scsi/rbscsi.c
+++ b/utils/scsi/rbscsi.c
@@ -18,6 +18,8 @@
* KIND, either express or implied.
*
****************************************************************************/
+#define _XOPEN_SOURCE 500
+#define _DEFAULT_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
@@ -47,6 +49,10 @@ typedef HANDLE rb_scsi_handle_t;
#include <errno.h>
#include <sys/ioctl.h>
#include <scsi/sg.h>
+#include <dirent.h>
+#include <linux/limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
#define RB_SCSI_LINUX
typedef int rb_scsi_handle_t;
#else
@@ -151,7 +157,175 @@ void rb_scsi_close(rb_scsi_device_t dev)
free(dev);
}
-/* Windpws */
+static int is_hctl(const char *name)
+{
+ char *end;
+ strtoul(name, &end, 0); /* h */
+ if(*end != ':')
+ return 0;
+ strtoul(end + 1, &end, 0); /* c */
+ if(*end != ':')
+ return 0;
+ strtoul(end + 1, &end, 0); /* t */
+ if(*end != ':')
+ return 0;
+ strtoul(end + 1, &end, 0); /* l */
+ return *end == 0;
+}
+
+static int _resolve_link_dev_path(char *path, size_t pathsz)
+{
+ /* make sure it is a directory */
+ struct stat st;
+ if(stat(path, &st) < 0)
+ return 0;
+ if(!S_ISDIR(st.st_mode))
+ return 0;
+ if(chdir(path) < 0)
+ return 0;
+ if(getcwd(path, pathsz) == NULL)
+ return 0;
+ return 1;
+}
+
+static int resolve_link_dev_path(char *path, size_t pathsz)
+{
+ /* change directory, ask the current path and resolve current directory */
+ char curdir[PATH_MAX];
+ if(getcwd(curdir, sizeof(curdir)) == NULL)
+ return 0;
+ int ret = _resolve_link_dev_path(path, pathsz);
+ chdir(curdir);
+ return ret;
+}
+
+static int scan_resolve_first_dev_path(char *path, size_t pathsz)
+{
+ size_t pathlen = strlen(path);
+ char *pathend = path + pathlen;
+ DIR *dir = opendir(path);
+ if(dir == NULL)
+ return 0;
+ struct dirent *d;
+ int ret = 0;
+ while((d = readdir(dir)))
+ {
+ if(!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
+ continue;
+ /* we found the entry, if it is a symlink, resolve it, otherwise it must be a directory */
+ if(d->d_type == DT_LNK)
+ {
+ snprintf(pathend, pathsz - pathlen, "/%s", d->d_name);
+ ret = resolve_link_dev_path(path, pathsz);
+ }
+ else if(d->d_type == DT_DIR)
+ {
+ snprintf(path, pathsz, "/dev/%s", d->d_name);
+ ret = 1;
+ }
+ break;
+ }
+ closedir(dir);
+ return ret;
+}
+
+static int scan_resolve_dev_path(char *path, size_t pathsz, const char *match)
+{
+ size_t pathlen = strlen(path);
+ char *pathend = path + pathlen;
+ DIR *dir = opendir(path);
+ if(dir == NULL)
+ return 0;
+ struct dirent *d;
+ int ret = 0;
+ while((d = readdir(dir)))
+ {
+ if(strcmp(d->d_name, match))
+ continue;
+ /* we found the entry, there are two case:
+ * - directory: we need to scan it and find the first entry
+ * - symlink: we need to see where it goes and extract the basename */
+ snprintf(pathend, pathsz - pathlen, "/%s", d->d_name);
+ if(d->d_type == DT_DIR)
+ ret = scan_resolve_first_dev_path(path, pathsz);
+ else if(d->d_type == DT_LNK)
+ ret = resolve_link_dev_path(path, pathsz);
+ break;
+ }
+ closedir(dir);
+ return ret;
+}
+
+static char *read_file_or_null(const char *path)
+{
+ FILE *f = fopen(path, "r");
+ if(f == NULL)
+ return NULL;
+ char buffer[1024];
+ if(fgets(buffer, sizeof(buffer), f) == NULL)
+ {
+ fclose(f);
+ return NULL;
+ }
+ fclose(f);
+ /* the kernel appends a '\n' at the end, remove it */
+ size_t len = strlen(buffer);
+ if(len > 0 && buffer[len - 1] == '\n')
+ buffer[len - 1] = 0;
+ return strdup(buffer);
+}
+
+struct rb_scsi_devent_t *rb_scsi_list(void)
+{
+ /* list devices in /sys/bus/scsi/devices
+ * we only keep entries of the form h:c:t:l */
+#define SYS_SCSI_DEV_PATH "/sys/bus/scsi/devices"
+ DIR *dir = opendir(SYS_SCSI_DEV_PATH);
+ if(dir == NULL)
+ return NULL;
+ struct dirent *d;
+ struct rb_scsi_devent_t *dev = malloc(sizeof(struct rb_scsi_devent_t));
+ dev[0].scsi_path = NULL;
+ dev[0].block_path = NULL;
+ int nr_dev = 0;
+ while((d = readdir(dir)))
+ {
+ if(!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
+ continue;
+ /* make sure the name is of the form h:c:t:l, we do not want targets or hosts */
+ if(!is_hctl(d->d_name))
+ continue;
+ /* we now need to scan the directory to find the block and scsi generic device path:
+ * block: there should be a 'block' entry
+ * scsi: there should be a 'scsi_generic' entry
+ * Both entries can either be a symlink to the devide, or a directory with a single entry */
+ char scsi_path[PATH_MAX];
+ snprintf(scsi_path, sizeof(scsi_path), SYS_SCSI_DEV_PATH "/%s", d->d_name);
+ if(!scan_resolve_dev_path(scsi_path, sizeof(scsi_path), "scsi_generic"))
+ continue;
+ char block_path[PATH_MAX];
+ snprintf(block_path, sizeof(block_path), SYS_SCSI_DEV_PATH "/%s", d->d_name);
+ if(!scan_resolve_dev_path(block_path, sizeof(block_path), "block"))
+ block_path[0] = 0;
+ dev = realloc(dev, (2 + nr_dev) * sizeof(struct rb_scsi_devent_t));
+ dev[nr_dev].scsi_path = strdup(scsi_path);
+ dev[nr_dev].block_path = block_path[0] == 0 ? NULL : strdup(block_path);
+ /* fill vendor/model/rev */
+ snprintf(scsi_path, sizeof(scsi_path), SYS_SCSI_DEV_PATH "/%s/vendor", d->d_name);
+ dev[nr_dev].vendor = read_file_or_null(scsi_path);
+ snprintf(scsi_path, sizeof(scsi_path), SYS_SCSI_DEV_PATH "/%s/model", d->d_name);
+ dev[nr_dev].model = read_file_or_null(scsi_path);
+ snprintf(scsi_path, sizeof(scsi_path), SYS_SCSI_DEV_PATH "/%s/rev", d->d_name);
+ dev[nr_dev].rev = read_file_or_null(scsi_path);
+
+ /* sentinel */
+ dev[++nr_dev].scsi_path = NULL;
+ dev[nr_dev].block_path = NULL;
+ }
+ closedir(dir);
+ return dev;
+}
+/* Windows */
#elif defined(RB_SCSI_WINDOWS)
/* return either path or something allocated with malloc() */
static const char *map_to_physical_drive(const char *path, unsigned flags, void *user,
@@ -275,6 +449,14 @@ void rb_scsi_close(rb_scsi_device_t dev)
free(dev);
}
+struct rb_scsi_devent_t *rb_scsi_list(void)
+{
+ /* unimplemented */
+ struct rb_scsi_devent_t *dev = malloc(sizeof(struct rb_scsi_devent_t));
+ dev[0].scsi_path = NULL;
+ dev[0].block_path = NULL;
+ return dev;
+}
/* other targets */
#else
rb_scsi_device_t rb_scsi_open(const char *path, unsigned flags, void *user,
@@ -297,6 +479,15 @@ void rb_scsi_close(rb_scsi_device_t dev)
{
free(dev);
}
+
+struct rb_scsi_devent_t *rb_scsi_list(void)
+{
+ /* unimplemented */
+ struct rb_scsi_devent_t *dev = malloc(sizeof(struct rb_scsi_devent_t));
+ dev[0].scsi_path = NULL;
+ dev[0].block_path = NULL;
+ return dev;
+}
#endif
void rb_scsi_decode_sense(rb_scsi_device_t dev, void *_sense, int sense_len)
@@ -333,3 +524,22 @@ void rb_scsi_decode_sense(rb_scsi_device_t dev, void *_sense, int sense_len)
#undef rb_printf
}
+
+void rb_scsi_free_list(struct rb_scsi_devent_t *list)
+{
+ if(list == NULL)
+ return;
+ for(struct rb_scsi_devent_t *p = list; p->scsi_path; p++)
+ {
+ free(p->scsi_path);
+ if(p->block_path)
+ free(p->block_path);
+ if(p->vendor)
+ free(p->vendor);
+ if(p->model)
+ free(p->model);
+ if(p->rev)
+ free(p->rev);
+ }
+ free(list);
+}