mpdparser: add some checks to duration parsing

https://bugzilla.gnome.org/show_bug.cgi?id=752336
This commit is contained in:
Vincent Penquerc'h 2015-11-02 10:25:38 +00:00
parent 7dca9fb3f4
commit 045a03c14a

View file

@ -939,6 +939,221 @@ convert_to_millisecs (guint decimals, gint pos)
return decimals * num / den;
}
static gboolean
accumulate (guint64 * v, guint64 mul, guint64 add)
{
guint64 tmp;
if (*v > G_MAXUINT64 / mul)
return FALSE;
tmp = *v * mul;
if (tmp > G_MAXUINT64 - add)
return FALSE;
*v = tmp + add;
return TRUE;
}
static gboolean
gst_mpdparser_parse_duration (const char *str, guint64 * value)
{
gint ret, len, pos, posT;
gint years = -1, months = -1, days = -1, hours = -1, minutes = -1, seconds =
-1, decimals = -1, read;
gboolean have_ms = FALSE;
guint64 tmp_value;
len = strlen (str);
GST_TRACE ("duration: %s, len %d", str, len);
if (strspn (str, "PT0123456789., \tHMDSY") < len) {
GST_WARNING ("Invalid character found: '%s'", str);
goto error;
}
/* skip leading/trailing whitespace */
while (strchr (" \t", str[0])) {
str++;
len--;
}
while (len > 0 && strchr (" \t", str[len - 1]))
--len;
/* read "P" for period */
if (str[0] != 'P') {
GST_WARNING ("P not found at the beginning of the string!");
goto error;
}
str++;
len--;
/* read "T" for time (if present) */
posT = strcspn (str, "T");
len -= posT;
if (posT > 0) {
/* there is some room between P and T, so there must be a period section */
/* read years, months, days */
do {
GST_TRACE ("parsing substring %s", str);
pos = strcspn (str, "YMD");
ret = sscanf (str, "%u", &read);
if (ret != 1) {
GST_WARNING ("can not read integer value from string %s!", str);
goto error;
}
switch (str[pos]) {
case 'Y':
if (years != -1 || months != -1 || days != -1) {
GST_WARNING ("year, month or day was already set");
goto error;
}
years = read;
break;
case 'M':
if (months != -1 || days != -1) {
GST_WARNING ("month or day was already set");
goto error;
}
months = read;
if (months >= 12) {
GST_WARNING ("Month out of range");
goto error;
}
break;
case 'D':
if (days != -1) {
GST_WARNING ("day was already set");
goto error;
}
days = read;
if (days >= 31) {
GST_WARNING ("Day out of range");
goto error;
}
break;
default:
GST_WARNING ("unexpected char %c!", str[pos]);
goto error;
break;
}
GST_TRACE ("read number %u type %c", read, str[pos]);
str += (pos + 1);
posT -= (pos + 1);
} while (posT > 0);
}
if (years == -1)
years = 0;
if (months == -1)
months = 0;
if (days == -1)
days = 0;
GST_TRACE ("Y:M:D=%d:%d:%d", years, months, days);
/* read "T" for time (if present) */
/* here T is at pos == 0 */
str++;
len--;
pos = 0;
if (pos < len) {
/* T found, there is a time section */
/* read hours, minutes, seconds, hundredths of second */
do {
GST_TRACE ("parsing substring %s", str);
pos = strcspn (str, "HMS,.");
ret = sscanf (str, "%u", &read);
if (ret != 1) {
GST_WARNING ("can not read integer value from string %s!", str);
goto error;
}
switch (str[pos]) {
case 'H':
if (hours != -1 || minutes != -1 || seconds != -1) {
GST_WARNING ("hour, minute or second was already set");
goto error;
}
hours = read;
if (hours >= 24) {
GST_WARNING ("Hour out of range");
goto error;
}
break;
case 'M':
if (minutes != -1 || seconds != -1) {
GST_WARNING ("minute or second was already set");
goto error;
}
minutes = read;
if (minutes >= 60) {
GST_WARNING ("Minute out of range");
goto error;
}
break;
case 'S':
if (have_ms) {
/* we have read the decimal part of the seconds */
decimals = convert_to_millisecs (read, pos);
GST_TRACE ("decimal number %u (%d digits) -> %d ms", read, pos,
decimals);
} else {
if (seconds != -1) {
GST_WARNING ("second was already set");
goto error;
}
/* no decimals */
seconds = read;
}
break;
case '.':
case ',':
/* we have read the integer part of a decimal number in seconds */
if (seconds != -1) {
GST_WARNING ("second was already set");
goto error;
}
seconds = read;
have_ms = TRUE;
break;
default:
GST_WARNING ("unexpected char %c!", str[pos]);
goto error;
break;
}
GST_TRACE ("read number %u type %c", read, str[pos]);
str += pos + 1;
len -= (pos + 1);
} while (len > 0);
}
if (hours == -1)
hours = 0;
if (minutes == -1)
minutes = 0;
if (seconds == -1)
seconds = 0;
if (decimals == -1)
decimals = 0;
GST_TRACE ("H:M:S.MS=%d:%d:%d.%03d", hours, minutes, seconds, decimals);
tmp_value = 0;
if (!accumulate (&tmp_value, 1, years)
|| !accumulate (&tmp_value, 365, months * 30)
|| !accumulate (&tmp_value, 1, days)
|| !accumulate (&tmp_value, 24, hours)
|| !accumulate (&tmp_value, 60, minutes)
|| !accumulate (&tmp_value, 60, seconds)
|| !accumulate (&tmp_value, 1000, decimals))
goto error;
/* ensure it can be converted from milliseconds to nanoseconds */
if (tmp_value > G_MAXUINT64 / 1000000)
goto error;
*value = tmp_value;
return TRUE;
error:
return FALSE;
}
static gboolean
gst_mpdparser_get_xml_prop_duration (xmlNode * a_node,
const gchar * property_name, guint64 default_value,
@ -946,171 +1161,18 @@ gst_mpdparser_get_xml_prop_duration (xmlNode * a_node,
{
xmlChar *prop_string;
gchar *str;
gint ret, len, pos, posT;
gint years = -1, months = -1, days = -1, hours = -1, minutes = -1, seconds =
-1, decimals = -1, read;
gboolean have_ms = FALSE;
gboolean exists = FALSE;
*property_value = default_value;
prop_string = xmlGetProp (a_node, (const xmlChar *) property_name);
if (prop_string) {
len = xmlStrlen (prop_string);
str = (gchar *) prop_string;
GST_TRACE ("duration: %s, len %d", str, len);
if (strchr (str, '-') != NULL) {
GST_WARNING ("'-' sign found while parsing unsigned duration");
if (!gst_mpdparser_parse_duration (str, property_value))
goto error;
}
/* read "P" for period */
pos = strcspn (str, "P");
if (pos != 0) {
GST_WARNING ("P not found at the beginning of the string!");
goto error;
}
str++;
len--;
/* read "T" for time (if present) */
posT = strcspn (str, "T");
len -= posT;
if (posT > 0) {
/* there is some room between P and T, so there must be a period section */
/* read years, months, days */
do {
GST_TRACE ("parsing substring %s", str);
pos = strcspn (str, "YMD");
ret = sscanf (str, "%u", &read);
if (ret != 1) {
GST_WARNING ("can not read integer value from string %s!", str);
goto error;
}
switch (str[pos]) {
case 'Y':
if (years != -1 || months != -1 || days != -1) {
GST_WARNING ("year, month or day was already set");
goto error;
}
years = read;
break;
case 'M':
if (months != -1 || days != -1) {
GST_WARNING ("month or day was already set");
goto error;
}
months = read;
break;
case 'D':
if (days != -1) {
GST_WARNING ("day was already set");
goto error;
}
days = read;
break;
default:
GST_WARNING ("unexpected char %c!", str[pos]);
goto error;
break;
}
GST_TRACE ("read number %u type %c", read, str[pos]);
str += (pos + 1);
posT -= (pos + 1);
} while (posT > 0);
}
if (years == -1)
years = 0;
if (months == -1)
months = 0;
if (days == -1)
days = 0;
GST_TRACE ("Y:M:D=%d:%d:%d", years, months, days);
/* read "T" for time (if present) */
/* here T is at pos == 0 */
str++;
len--;
pos = 0;
if (pos < len) {
/* T found, there is a time section */
/* read hours, minutes, seconds, cents of second */
do {
GST_TRACE ("parsing substring %s", str);
pos = strcspn (str, "HMS,.");
ret = sscanf (str, "%u", &read);
if (ret != 1) {
GST_WARNING ("can not read integer value from string %s!", str);
goto error;
}
switch (str[pos]) {
case 'H':
if (hours != -1 || minutes != -1 || seconds != -1) {
GST_WARNING ("hour, minute or second was already set");
goto error;
}
hours = read;
break;
case 'M':
if (minutes != -1 || seconds != -1) {
GST_WARNING ("minute or second was already set");
goto error;
}
minutes = read;
break;
case 'S':
if (have_ms) {
/* we have read the decimal part of the seconds */
decimals = convert_to_millisecs (read, pos);
GST_TRACE ("decimal number %u (%d digits) -> %d ms", read, pos,
decimals);
} else {
if (seconds != -1) {
GST_WARNING ("second was already set");
goto error;
}
/* no decimals */
seconds = read;
}
break;
case '.':
case ',':
/* we have read the integer part of a decimal number in seconds */
if (seconds != -1) {
GST_WARNING ("second was already set");
goto error;
}
seconds = read;
have_ms = TRUE;
break;
default:
GST_WARNING ("unexpected char %c!", str[pos]);
goto error;
break;
}
GST_TRACE ("read number %u type %c", read, str[pos]);
str += pos + 1;
len -= (pos + 1);
} while (len > 0);
}
if (hours == -1)
hours = 0;
if (minutes == -1)
minutes = 0;
if (seconds == -1)
seconds = 0;
if (decimals == -1)
decimals = 0;
GST_TRACE ("H:M:S.MS=%d:%d:%d.%03d", hours, minutes, seconds, decimals);
GST_LOG (" - %s: %" G_GUINT64_FORMAT, property_name, *property_value);
xmlFree (prop_string);
exists = TRUE;
*property_value =
(((((guint64) years * 365 + months * 30 + days) * 24 +
hours) * 60 + minutes) * 60 + seconds) * 1000 + decimals;
GST_LOG (" - %s: %" G_GUINT64_FORMAT, property_name, *property_value);
}
return exists;
error: