ucm: implement sysset sequence command

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

src/ucm/main.c

@@ -31,6 +31,7 @@
  */
 
 #include "ucm_local.h"
+#include <stdbool.h>
 #include <ctype.h>
 #include <stdarg.h>
 #include <pthread.h>
@@ -323,6 +324,72 @@ static int execute_cset(snd_ctl_t *ctl, const char *cset, unsigned int type)
 	return err;
 }
 
+static int execute_sysset(const char *sysset)
+{
+	char path[PATH_MAX];
+	const char *e;
+	char *s, *value;
+	ssize_t wlen;
+	size_t len;
+	int fd, myerrno;
+	bool ignore_error = false;
+
+	if (sysset == NULL || *sysset == '\0')
+		return 0;
+
+	ignore_error = sysset[0] == '-';
+
+	if (sysset[0] == ':')
+		return -EINVAL;
+
+	s = strdup(sysset[0] != '/' ? sysset : sysset + 1);
+	if (s == NULL)
+		return -ENOMEM;
+
+	value = strchr(s, ':');
+	if (!value) {
+		free(s);
+		return -EINVAL;
+	}
+	*value = '\0';
+	value++;
+	len = strlen(value);
+	if (len < 1) {
+		free(s);
+		return -EINVAL;
+	}
+
+	e = uc_mgr_sysfs_root();
+	if (e == NULL) {
+		free(s);
+		return -EINVAL;
+	}
+	snprintf(path, sizeof(path), "%s/%s", e, s);
+
+	fd = open(path, O_WRONLY|O_CLOEXEC);
+	if (fd < 0) {
+		free(s);
+		if (ignore_error)
+			return 0;
+		uc_error("unable to open '%s' for write", path);
+		return -EINVAL;
+	}
+	wlen = write(fd, value, len);
+	myerrno = errno;
+	close(fd);
+	free(s);
+
+	if (ignore_error)
+		return 0;
+
+	if (wlen != (ssize_t)len) {
+		uc_error("unable to write '%s' to '%s': %s", value, path, strerror(myerrno));
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 /**
  * \brief Execute the sequence
  * \param uc_mgr Use case manager
@@ -420,6 +487,11 @@ static int execute_sequence(snd_use_case_mgr_t *uc_mgr,
 				goto __fail;
 			}
 			break;
+		case SEQUENCE_ELEMENT_TYPE_SYSSET:
+			err = execute_sysset(s->data.sysset);
+			if (err < 0)
+				goto __fail;
+			break;
 		case SEQUENCE_ELEMENT_TYPE_SLEEP:
 			usleep(s->data.sleep);
 			break;

src/ucm/parser.c

@@ -772,6 +772,16 @@ static int parse_sequence(snd_use_case_mgr_t *uc_mgr,
 			continue;
 		}
 
+		if (strcmp(cmd, "sysset") == 0) {
+			curr->type = SEQUENCE_ELEMENT_TYPE_SYSSET;
+			err = parse_string_substitute3(uc_mgr, n, &curr->data.sysset);
+			if (err < 0) {
+				uc_error("error: sysset requires a string!");
+				return err;
+			}
+			continue;
+		}
+
 		if (strcmp(cmd, "usleep") == 0) {
 			curr->type = SEQUENCE_ELEMENT_TYPE_SLEEP;
 			err = parse_integer_substitute3(uc_mgr, n, &curr->data.sleep);

src/ucm/ucm_local.h

@@ -52,6 +52,7 @@
 #define SEQUENCE_ELEMENT_TYPE_CSET_BIN_FILE	5
 #define SEQUENCE_ELEMENT_TYPE_CSET_TLV		6
 #define SEQUENCE_ELEMENT_TYPE_CMPT_SEQ		7
+#define SEQUENCE_ELEMENT_TYPE_SYSSET		8
 
 struct ucm_value {
         struct list_head list;
@@ -73,6 +74,7 @@ struct sequence_element {
 		char *cdev;
 		char *cset;
 		char *exec;
+		char *sysset;
 		struct component_sequence cmpt_seq; /* component sequence */
 	} data;
 };
@@ -269,6 +271,7 @@ struct snd_use_case_mgr {
 void uc_mgr_error(const char *fmt, ...);
 void uc_mgr_stdout(const char *fmt, ...);
 
+const char *uc_mgr_sysfs_root(void);
 const char *uc_mgr_config_dir(int format);
 int uc_mgr_config_load(int format, const char *file, snd_config_t **cfg);
 int uc_mgr_config_load_file(snd_use_case_mgr_t *uc_mgr,  const char *file, snd_config_t **cfg);

src/ucm/ucm_subs.c

@@ -508,12 +508,12 @@ static char *rval_sysfs(snd_use_case_mgr_t *uc_mgr ATTRIBUTE_UNUSED, const char
 	char path[PATH_MAX], link[PATH_MAX + 1];
 	struct stat sb;
 	ssize_t len;
-	char *e;
+	const char *e;
 	int fd;
 
-	e = getenv("SYSFS_PATH");
+	e = uc_mgr_sysfs_root();
 	if (e == NULL)
-		e = "/sys";
+		return NULL;
 	if (id[0] == '/')
 		id++;
 	snprintf(path, sizeof(path), "%s/%s", e, id);

src/ucm/utils.c

@@ -49,6 +49,16 @@ void uc_mgr_stdout(const char *fmt,...)
 	va_end(va);
 }
 
+const char *uc_mgr_sysfs_root(void)
+{
+	const char *e = getenv("SYSFS_PATH");
+	if (e == NULL)
+		return "/sys";
+	if (*e == '\0')
+		uc_error("no sysfs root!");
+	return e;
+}
+
 struct ctl_list *uc_mgr_get_master_ctl(snd_use_case_mgr_t *uc_mgr)
 {
 	struct list_head *pos;
@@ -479,6 +489,9 @@ void uc_mgr_free_sequence_element(struct sequence_element *seq)
 	case SEQUENCE_ELEMENT_TYPE_CSET_TLV:
 		free(seq->data.cset);
 		break;
+	case SEQUENCE_ELEMENT_TYPE_SYSSET:
+		free(seq->data.sysset);
+		break;
 	case SEQUENCE_ELEMENT_TYPE_EXEC:
 		free(seq->data.exec);
 		break;