*/
x = opt_state->all_dom_sets;
/*
- * XXX - what if the multiplication overflows?
+ * In opt_init(), we've made sure the product doesn't overflow.
*/
i = opt_state->n_blocks * opt_state->nodewords;
while (i != 0) {
x = opt_state->all_edge_sets;
/*
- * XXX - what if the multiplication overflows?
+ * In opt_init(), we've made sure the product doesn't overflow.
*/
for (i = opt_state->n_edges * opt_state->edgewords; i != 0; ) {
--i;
static void
number_blks_r(opt_state_t *opt_state, struct icode *ic, struct block *p)
{
- int n;
+ u_int n;
if (p == 0 || isMarked(ic, p))
return;
Mark(ic, p);
n = opt_state->n_blocks++;
+ if (opt_state->n_blocks == 0) {
+ /*
+ * Overflow.
+ */
+ opt_error(opt_state, "filter is too complex to optimize");
+ }
p->id = n;
opt_state->blocks[n] = p;
{
bpf_u_int32 *p;
int i, n, max_stmts;
+ u_int product;
+ size_t block_memsize, edge_memsize;
/*
* First, count the blocks, so we can malloc an array to map
opt_state->n_blocks = 0;
number_blks_r(opt_state, ic, ic->root);
+ /*
+ * This "should not happen".
+ */
+ if (opt_state->n_blocks == 0)
+ opt_error(opt_state, "filter has no instructions; please report this as a libpcap issue");
+
opt_state->n_edges = 2 * opt_state->n_blocks;
+ if ((opt_state->n_edges / 2) != opt_state->n_blocks) {
+ /*
+ * Overflow.
+ */
+ opt_error(opt_state, "filter is too complex to optimize");
+ }
opt_state->edges = (struct edge **)calloc(opt_state->n_edges, sizeof(*opt_state->edges));
if (opt_state->edges == NULL) {
opt_error(opt_state, "malloc");
opt_state->edgewords = opt_state->n_edges / BITS_PER_WORD + 1;
opt_state->nodewords = opt_state->n_blocks / BITS_PER_WORD + 1;
+ /*
+ * Make sure opt_state->n_blocks * opt_state->nodewords fits
+ * in a u_int; we use it as a u_int number-of-iterations
+ * value.
+ */
+ product = opt_state->n_blocks * opt_state->nodewords;
+ if ((product / opt_state->n_blocks) != opt_state->nodewords) {
+ /*
+ * XXX - just punt and don't try to optimize?
+ * In practice, this is unlikely to happen with
+ * a normal filter.
+ */
+ opt_error(opt_state, "filter is too complex to optimize");
+ }
+
+ /*
+ * Make sure the total memory required for that doesn't
+ * overflow.
+ */
+ block_memsize = (size_t)2 * product * sizeof(*opt_state->space);
+ if ((block_memsize / product) != 2 * sizeof(*opt_state->space)) {
+ opt_error(opt_state, "filter is too complex to optimize");
+ }
+
+ /*
+ * Make sure opt_state->n_edges * opt_state->edgewords fits
+ * in a u_int; we use it as a u_int number-of-iterations
+ * value.
+ */
+ product = opt_state->n_edges * opt_state->edgewords;
+ if ((product / opt_state->n_edges) != opt_state->edgewords) {
+ opt_error(opt_state, "filter is too complex to optimize");
+ }
+
+ /*
+ * Make sure the total memory required for that doesn't
+ * overflow.
+ */
+ edge_memsize = (size_t)product * sizeof(*opt_state->space);
+ if (edge_memsize / product != sizeof(*opt_state->space)) {
+ opt_error(opt_state, "filter is too complex to optimize");
+ }
+
+ /*
+ * Make sure the total memory required for both of them dosn't
+ * overflow.
+ */
+ if (block_memsize > SIZE_MAX - edge_memsize) {
+ opt_error(opt_state, "filter is too complex to optimize");
+ }
+
/* XXX */
- opt_state->space = (bpf_u_int32 *)malloc(2 * opt_state->n_blocks * opt_state->nodewords * sizeof(*opt_state->space)
- + opt_state->n_edges * opt_state->edgewords * sizeof(*opt_state->space));
+ opt_state->space = (bpf_u_int32 *)malloc(block_memsize + edge_memsize);
if (opt_state->space == NULL) {
opt_error(opt_state, "malloc");
}
struct slist *src;
u_int slen;
u_int off;
- u_int extrajmps; /* number of extra jumps inserted */
struct slist **offset = NULL;
if (p == 0 || isMarked(ic, p))
dst->code = (u_short)p->s.code;
dst->k = p->s.k;
if (JT(p)) {
- extrajmps = 0;
+ /* number of extra jumps inserted */
+ u_char extrajmps = 0;
off = JT(p)->offset - (p->offset + slen) - 1;
if (off >= 256) {
/* offset too large for branch, must add a jump */
p->longjt++;
return(0);
}
- /* branch if T to following jump */
- if (extrajmps >= 256) {
- conv_error(conv_state, "too many extra jumps");
- /*NOTREACHED*/
- }
- dst->jt = (u_char)extrajmps;
+ dst->jt = extrajmps;
extrajmps++;
dst[extrajmps].code = BPF_JMP|BPF_JA;
dst[extrajmps].k = off - extrajmps;
}
/* branch if F to following jump */
/* if two jumps are inserted, F goes to second one */
- if (extrajmps >= 256) {
- conv_error(conv_state, "too many extra jumps");
- /*NOTREACHED*/
- }
- dst->jf = (u_char)extrajmps;
+ dst->jf = extrajmps;
extrajmps++;
dst[extrajmps].code = BPF_JMP|BPF_JA;
dst[extrajmps].k = off - extrajmps;
icount = slength(block->stmts) + 1 + block->longjt + block->longjf;
noffset = min(block->offset + icount, (int)prog->bf_len);
- fprintf(out, "\tblock%d [shape=ellipse, id=\"block-%d\" label=\"BLOCK%d\\n", block->id, block->id, block->id);
+ fprintf(out, "\tblock%u [shape=ellipse, id=\"block-%u\" label=\"BLOCK%u\\n", block->id, block->id, block->id);
for (i = block->offset; i < noffset; i++) {
fprintf(out, "\\n%s", bpf_image(prog->bf_insns + i, i));
}
Mark(ic, block);
if (JT(block)) {
- fprintf(out, "\t\"block%d\":se -> \"block%d\":n [label=\"T\"]; \n",
+ fprintf(out, "\t\"block%u\":se -> \"block%u\":n [label=\"T\"]; \n",
block->id, JT(block)->id);
- fprintf(out, "\t\"block%d\":sw -> \"block%d\":n [label=\"F\"]; \n",
+ fprintf(out, "\t\"block%u\":sw -> \"block%u\":n [label=\"F\"]; \n",
block->id, JF(block)->id);
}
dot_dump_edge(ic, JT(block), out);
projects / libpcap / blobdiff