Add sbuf_copyin(). Also add 'b' variants of sbuf_{cat,copyin,cpy}() which

ignore NUL bytes in the source string.

share/man/man9/sbuf.9

@@ -32,7 +32,11 @@
 .Nm sbuf_new ,
 .Nm sbuf_clear ,
 .Nm sbuf_setpos ,
+.Nm sbuf_bcat ,
+.Nm sbuf_bcopyin ,
+.Nm sbuf_bcpy ,
 .Nm sbuf_cat ,
+.Nm sbuf_copyin ,
 .Nm sbuf_cpy ,
 .Nm sbuf_printf ,
 .Nm sbuf_putc ,
@@ -52,8 +56,16 @@
 .Ft int
 .Fn sbuf_setpos "struct sbuf *s" "int pos"
 .Ft int
+.Fn sbuf_bcat "struct sbuf *s" "const char *str" "size_t len"
+.Ft int
+.Fn sbuf_bcopyin "struct sbuf *s" "const void *uaddr" "size_t len"
+.Ft int
+.Fn sbuf_bcpy "struct sbuf *s" "const char *str" "size_t len"
+.Ft int
 .Fn sbuf_cat "struct sbuf *s" "const char *str"
 .Ft int
+.Fn sbuf_copyin "struct sbuf *s" "const void *uaddr" "size_t len"
+.Ft int
 .Fn sbuf_cpy "struct sbuf *s" "const char *str"
 .Ft int
 .Fn sbuf_printf "struct sbuf *s" "char *fmt" "..."
@@ -131,18 +143,57 @@ which is a value between zero and one less than the size of the
 storage buffer.
 .Pp
 The
+.Fn sbuf_bcat
+function appends the first
+.Fa len
+bytes from the byte string
+.Fa str
+to the
+.Fa sbuf .
+.Pp
+The
+.Fn sbuf_bcopyin
+function copies
+.Fa len
+bytes from the specified userland address into the
+.Fa sbuf .
+.Pp
+The
+.Fn sbuf_bcpy
+function replaces the contents of the
+.Fa sbuf
+with the first
+.Fa len
+bytes from the byte string
+.Fa str .
+.Pp
+The
 .Fn sbuf_cat
-function appends the string
+function appends the NUL-terminated string
 .Fa str
 to the
 .Fa sbuf
 at the current position.
 .Pp
 The
+.Fn sbuf_copyin
+function copies a NUL-terminated string from the specified userland
+address into the
+.Fa sbuf .
+If the
+.Fa len
+argument is non-zero, no more than
+.Fa len
+characters (not counting the terminating NUL) are copied; otherwise
+the entire string, or as much of it as can fit in the
+.Fa sbuf ,
+is copied.
+.Pp
+The
 .Fn sbuf_cpy
 function replaces the contents of the
 .Fa sbuf
-with those of the string
+with those of the NUL-terminated string
 .Fa str .
 This is equivalent to calling
 .Fn sbuf_cat
@@ -248,6 +299,8 @@ return
 .Dv NULL
 and \-1, respectively, if the buffer overflowed.
 .Sh SEE ALSO
+.Xr copyin 9 ,
+.Xr copyinstr 9 ,
 .Xr printf 3 ,
 .Xr strcat 3 ,
 .Xr strcpy 3

sys/kern/subr_sbuf.c

@@ -166,6 +166,72 @@ sbuf_setpos(struct sbuf *s, int pos)
 	return (0);
 }
 
+/*
+ * Append a byte string to an sbuf.
+ */
+int
+sbuf_bcat(struct sbuf *s, const char *str, size_t len)
+{
+	assert_sbuf_integrity(s);
+	assert_sbuf_state(s, 0);
+	
+	if (SBUF_HASOVERFLOWED(s))
+		return (-1);
+	
+	while (len-- && SBUF_HASROOM(s))
+		s->s_buf[s->s_len++] = *str++;
+	if (len) {
+		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
+		return (-1);
+	}
+	return (0);
+}
+
+#ifdef _KERNEL
+/*
+ * Copy a byte string from userland into an sbuf.
+ */
+int
+sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
+{
+	assert_sbuf_integrity(s);
+	assert_sbuf_state(s, 0);
+
+	if (SBUF_HASOVERFLOWED(s))
+		return (-1);
+
+	if (len == 0)
+		return (0);
+	if (len > (s->s_size - s->s_len - 1))
+		len = s->s_size - s->s_len - 1;
+	switch (copyin(uaddr, s->s_buf + s->s_len, len)) {
+	case ENAMETOOLONG:
+		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
+		/* fall through */
+	case 0:
+		s->s_len += len;
+		break;
+	default:
+		return (-1);	/* XXX */
+	}
+	
+	return (0);
+}
+#endif
+
+/*
+ * Copy a byte string into an sbuf.
+ */
+int
+sbuf_bcpy(struct sbuf *s, const char *str, size_t len)
+{
+	assert_sbuf_integrity(s);
+	assert_sbuf_state(s, 0);
+	
+	sbuf_clear(s);
+	return (sbuf_bcat(s, str, len));
+}
+
 /*
  * Append a string to an sbuf.
  */
@@ -187,6 +253,38 @@ sbuf_cat(struct sbuf *s, const char *str)
 	return (0);
 }
 
+#ifdef _KERNEL
+/*
+ * Copy a string from userland into an sbuf.
+ */
+int
+sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
+{
+	size_t done;
+	
+	assert_sbuf_integrity(s);
+	assert_sbuf_state(s, 0);
+
+	if (SBUF_HASOVERFLOWED(s))
+		return (-1);
+
+	if (len == 0 || len > (s->s_size - s->s_len - 1))
+		len = s->s_size - s->s_len - 1;
+	switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
+	case ENAMETOOLONG:
+		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
+		/* fall through */
+	case 0:
+		s->s_len += done - 1;
+		break;
+	default:
+		return (-1);	/* XXX */
+	}
+	
+	return (0);
+}
+#endif
+
 /*
  * Copy a string into an sbuf.
  */

sys/sys/sbuf.h

@@ -54,6 +54,8 @@ __BEGIN_DECLS
 struct sbuf	*sbuf_new(struct sbuf *s, char *buf, int length, int flags);
 void		 sbuf_clear(struct sbuf *s);
 int		 sbuf_setpos(struct sbuf *s, int pos);
+int		 sbuf_bcat(struct sbuf *s, const char *str, size_t len);
+int		 sbuf_bcpy(struct sbuf *s, const char *str, size_t len);
 int		 sbuf_cat(struct sbuf *s, const char *str);
 int		 sbuf_cpy(struct sbuf *s, const char *str);
 int		 sbuf_printf(struct sbuf *s, char *fmt, ...);
@@ -63,6 +65,11 @@ void		 sbuf_finish(struct sbuf *s);
 char		*sbuf_data(struct sbuf *s);
 int		 sbuf_len(struct sbuf *s);
 void		 sbuf_delete(struct sbuf *s);
+
+#ifdef _KERNEL
+int		 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len);
+int		 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len);
+#endif
 __END_DECLS
 
 #endif