When the user reads the contents of a STRING parameter via sysfs, Speakup
surrounds the data with a balanced pair of quotes. Example:
"\x01+3p"
The kernel appends a newline.
When the user tries to set a parameter via sysfs, Speakup should strip
away the newline and balanced quotes. Thus, reads and writes of files
under /sys/modules/speakup/parameters should be inverses of one another.
This patch guarantees such behavior.
---
src/paramhelpers.c | 2 +-
src/varhandlers.c | 20 ++++++++++++++++++--
2 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/src/paramhelpers.c b/src/paramhelpers.c
index 7dbd060..1bbfe17 100644
--- a/src/paramhelpers.c
+++ b/src/paramhelpers.c
@@ -755,8 +755,8 @@ static int set_vars(const char *val, struct kernel_param *kp)
return 0;
ret = 0;
- len = strlen(val);
cp = xlate((char *) val);
+ len = strlen(val); /* xlate may have changed the length of the string */
switch (param->var_type) {
case VAR_NUM:
case VAR_TIME:
diff --git a/src/varhandlers.c b/src/varhandlers.c
index a79b03a..1c3d1f5 100644
--- a/src/varhandlers.c
+++ b/src/varhandlers.c
@@ -240,6 +240,20 @@ int set_string_var(const char *page, struct st_var_header *var, int len)
struct var_t *var_data = var->data;
if (var_data == NULL)
return E_UNDEF;
+
+ /*
+ * The user might supply a parameter as "param"<newline>, because
+ * this is the representation that Speakup uses when producing data
+ * for the STRING parameter files under /sys. Snip the balanced
+ * quotes and newline, if present.
+ */
+
+ if((len >= 1) && (page[len - 1] == '\n'))
+ --len;
+ if((len >= 2) && (page[0] == '"') && (page[len - 1] == '"')) {
+ ++page;
+ len -= 2; /* balanced pair of quotes */
+ }
if (len > MAXVARLEN)
return -E_TOOLONG;
if (!len) {
@@ -250,8 +264,10 @@ int set_string_var(const char *page, struct st_var_header *var, int len)
var->p_val = var_data->u.s.default_val;
if (var->p_val != var_data->u.s.default_val)
strcpy((char *)var->p_val, var_data->u.s.default_val);
- } else if (var->p_val)
- strcpy((char *)var->p_val, page);
+ } else if (var->p_val) {
+ strncpy((char *)var->p_val, page, len);
+ ((char *) var->p_val)[len] = '\0';
+ }
else
return -E_TOOLONG;
return ret;
--
1.6.3.1
