RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 13:48:12 +00:00
Code Issues Activity Actions

LibC: Fix bug in scanf() family where we'd capture invalid data.

Browse source
This commit is contained in:
Andreas Kling 2019-03-20 15:29:04 +01:00
parent 951377e93e
commit cdb82f6fbb
3 changed files with 54 additions and 50 deletions
Download patch file Download diff file Expand all files Collapse all files

66
LibC/scanf.cpp
View file

@ -33,8 +33,6 @@
#include <string.h>
#include <ctype.h>
#define MAXLN 512
static const char* determine_base(const char* p, int& base)
{
if (p[0] == '0') {
@ -119,54 +117,13 @@ int atob(unsigned int* vp, const char* p, int base)
return 0;
}
static int vfscanf(FILE*, const char*, va_list);
static int vsscanf(const char*, const char*, va_list);
#define ISSPACE " \t\n\r\f\v"
int scanf(const char* fmt, ...)
{
int count;
va_list ap;
va_start(ap, fmt);
count = vfscanf(stdin, fmt, ap);
va_end(ap);
return count;
}
int fscanf(FILE *fp, const char* fmt, ...)
{
va_list ap;
va_start(ap, fmt);
int count = vfscanf(fp, fmt, ap);
va_end(ap);
return count;
}
int sscanf(const char *buf, const char* fmt, ...)
{
va_list ap;
va_start(ap, fmt);
int count = vsscanf(buf, fmt, ap);
va_end(ap);
return count;
}
static int vfscanf(FILE *fp, const char* fmt, va_list ap)
{
char buf[MAXLN + 1];
if (!fgets(buf, MAXLN, fp))
return -1;
int count = vsscanf(buf, fmt, ap);
return count;
}
static int vsscanf(const char *buf, const char *s, va_list ap)
int vsscanf(const char *buf, const char *s, va_list ap)
{
int base = 10;
char *t;
char tmp[MAXLN];
char tmp[BUFSIZ];
bool noassign = false;
int count = 0;
int width = 0;
@ -220,16 +177,25 @@ static int vsscanf(const char *buf, const char *s, va_list ap)
else if (*s == 'b')
base = 2;
if (!width) {
if (isspace(*(s + 1)) || *(s + 1) == 0)
if (isspace(*(s + 1)) || *(s + 1) == 0) {
width = strcspn(buf, ISSPACE);
else
width = strchr(buf, *(s + 1)) - buf;
} else {
auto* p = strchr(buf, *(s+1));
if (p)
width = p - buf;
else {
noassign = true;
width = 0;
}
}
}
strncpy(tmp, buf, width);
tmp[width] = '\0';
buf += width;
if (!noassign)
atob(va_arg(ap, uint32_t*), tmp, base);
if (!noassign) {
if (!atob(va_arg(ap, uint32_t*), tmp, base))
noassign = true;
}
}
if (!noassign)
++count;