diff options
| -rw-r--r-- | src/buffer.c | 40 |
1 files changed, 25 insertions, 15 deletions
diff --git a/src/buffer.c b/src/buffer.c index f74c8c6..78be967 100644 --- a/src/buffer.c +++ b/src/buffer.c @@ -4,6 +4,7 @@ #include <string.h> #include <stdio.h> #include <stdlib.h> +#include <stdint.h> #include "config.h" #include "cmark_ctype.h" @@ -14,10 +15,6 @@ */ unsigned char cmark_strbuf__initbuf[1]; -#define ENSURE_SIZE(b, d) \ - if ((d) >= b->asize) \ - cmark_strbuf_grow(b, (d)); \ - #ifndef MIN #define MIN(x,y) ((x<y) ? x : y) #endif @@ -38,6 +35,21 @@ void cmark_strbuf_overflow_err() { abort(); } +static inline void +S_strbuf_grow_by(cmark_strbuf *buf, size_t add) { + size_t target_size = (size_t)buf->size + add; + + if (target_size < add /* Integer overflow. */ + || target_size > BUFSIZE_MAX /* Truncation overflow. */ + ) { + cmark_strbuf_overflow_err(); + return; /* unreachable */ + } + + if ((bufsize_t)target_size >= buf->asize) + cmark_strbuf_grow(buf, (bufsize_t)target_size); +} + void cmark_strbuf_grow(cmark_strbuf *buf, bufsize_t target_size) { unsigned char *new_ptr; @@ -113,7 +125,8 @@ void cmark_strbuf_set(cmark_strbuf *buf, const unsigned char *data, bufsize_t le cmark_strbuf_clear(buf); } else { if (data != buf->ptr) { - ENSURE_SIZE(buf, len); + if (len >= buf->asize) + cmark_strbuf_grow(buf, len); memmove(buf->ptr, data, len); } buf->size = len; @@ -129,8 +142,7 @@ void cmark_strbuf_sets(cmark_strbuf *buf, const char *string) void cmark_strbuf_putc(cmark_strbuf *buf, int c) { - // TODO: Check for overflow. - ENSURE_SIZE(buf, buf->size + 1); + S_strbuf_grow_by(buf, 1); buf->ptr[buf->size++] = c; buf->ptr[buf->size] = '\0'; } @@ -140,8 +152,7 @@ void cmark_strbuf_put(cmark_strbuf *buf, const unsigned char *data, bufsize_t le if (len <= 0) return; - // TODO: Check for overflow. - ENSURE_SIZE(buf, buf->size + len); + S_strbuf_grow_by(buf, len); memmove(buf->ptr + buf->size, data, len); buf->size += len; buf->ptr[buf->size] = '\0'; @@ -154,10 +165,10 @@ void cmark_strbuf_puts(cmark_strbuf *buf, const char *string) void cmark_strbuf_vprintf(cmark_strbuf *buf, const char *format, va_list ap) { - // TODO: Check for overflow. - const bufsize_t expected_size = buf->size + (strlen(format) * 2); - - ENSURE_SIZE(buf, expected_size); + size_t expected_size = strlen(format); + if (expected_size <= SIZE_MAX / 2) + expected_size *= 2; + S_strbuf_grow_by(buf, expected_size); while (1) { va_list args; @@ -188,8 +199,7 @@ void cmark_strbuf_vprintf(cmark_strbuf *buf, const char *format, va_list ap) break; } - // TODO: Check for overflow. - ENSURE_SIZE(buf, buf->size + len); + S_strbuf_grow_by(buf, len); } } |