#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
+#include <setjmp.h>
#include <string.h>
#include <errno.h>
#include "pcap-int.h"
#include "gencode.h"
+#include "optimize.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
#ifdef BDEBUG
-int pcap_optimizer_debug;
+/*
+ * The internal "debug printout" flag for the filter expression optimizer.
+ * The code to print that stuff is present only if BDEBUG is defined, so
+ * the flag, and the routine to set it, are defined only if BDEBUG is
+ * defined.
+ */
+static int pcap_optimizer_debug;
+
+/*
+ * Routine to set that flag.
+ *
+ * This is intended for libpcap developers, not for general use.
+ * If you want to set these in a program, you'll have to declare this
+ * routine yourself, with the appropriate DLL import attribute on Windows;
+ * it's not declared in any header file, and won't be declared in any
+ * header file provided by libpcap.
+ */
+PCAP_API void pcap_set_optimizer_debug(int value);
+
+PCAP_API_DEF void
+pcap_set_optimizer_debug(int value)
+{
+ pcap_optimizer_debug = value;
+}
+
+/*
+ * The internal "print dot graph" flag for the filter expression optimizer.
+ * The code to print that stuff is present only if BDEBUG is defined, so
+ * the flag, and the routine to set it, are defined only if BDEBUG is
+ * defined.
+ */
+static int pcap_print_dot_graph;
+
+/*
+ * Routine to set that flag.
+ *
+ * This is intended for libpcap developers, not for general use.
+ * If you want to set these in a program, you'll have to declare this
+ * routine yourself, with the appropriate DLL import attribute on Windows;
+ * it's not declared in any header file, and won't be declared in any
+ * header file provided by libpcap.
+ */
+PCAP_API void pcap_set_print_dot_graph(int value);
+
+PCAP_API_DEF void
+pcap_set_print_dot_graph(int value)
+{
+ pcap_print_dot_graph = value;
+}
+
#endif
/*
*/
struct valnode {
int code;
- int v0, v1;
- int val;
+ bpf_u_int32 v0, v1;
+ int val; /* the value number */
struct valnode *next;
};
/* Integer constants mapped with the load immediate opcode. */
-#define K(i) F(opt_state, BPF_LD|BPF_IMM|BPF_W, i, 0L)
+#define K(i) F(opt_state, BPF_LD|BPF_IMM|BPF_W, i, 0U)
struct vmapinfo {
int is_const;
- bpf_int32 const_val;
+ bpf_u_int32 const_val;
};
typedef struct {
+ /*
+ * Place to longjmp to on an error.
+ */
+ jmp_buf top_ctx;
+
+ /*
+ * The buffer into which to put error message.
+ */
+ char *errbuf;
+
/*
* A flag to indicate that further optimization is needed.
* Iterative passes are continued until a given pass yields no
* True if a is in uset {p}
*/
#define SET_MEMBER(p, a) \
-((p)[(unsigned)(a) / BITS_PER_WORD] & (1 << ((unsigned)(a) % BITS_PER_WORD)))
+((p)[(unsigned)(a) / BITS_PER_WORD] & ((bpf_u_int32)1 << ((unsigned)(a) % BITS_PER_WORD)))
/*
* Add 'a' to uset p.
*/
#define SET_INSERT(p, a) \
-(p)[(unsigned)(a) / BITS_PER_WORD] |= (1 << ((unsigned)(a) % BITS_PER_WORD))
+(p)[(unsigned)(a) / BITS_PER_WORD] |= ((bpf_u_int32)1 << ((unsigned)(a) % BITS_PER_WORD))
/*
* Delete 'a' from uset p.
*/
#define SET_DELETE(p, a) \
-(p)[(unsigned)(a) / BITS_PER_WORD] &= ~(1 << ((unsigned)(a) % BITS_PER_WORD))
+(p)[(unsigned)(a) / BITS_PER_WORD] &= ~((bpf_u_int32)1 << ((unsigned)(a) % BITS_PER_WORD))
/*
* a := a intersect b
#define MODULUS 213
struct valnode *hashtbl[MODULUS];
- int curval;
- int maxval;
+ bpf_u_int32 curval;
+ bpf_u_int32 maxval;
struct vmapinfo *vmap;
struct valnode *vnode_base;
} opt_state_t;
typedef struct {
+ /*
+ * Place to longjmp to on an error.
+ */
+ jmp_buf top_ctx;
+
+ /*
+ * The buffer into which to put error message.
+ */
+ char *errbuf;
+
/*
* Some pointers used to convert the basic block form of the code,
* into the array form that BPF requires. 'fstart' will point to
struct bpf_insn *ftail;
} conv_state_t;
-static void opt_init(compiler_state_t *, opt_state_t *, struct icode *);
+static void opt_init(opt_state_t *, struct icode *);
static void opt_cleanup(opt_state_t *);
+static void PCAP_NORETURN opt_error(opt_state_t *, const char *, ...)
+ PCAP_PRINTFLIKE(2, 3);
static void intern_blocks(opt_state_t *, struct icode *);
static void find_inedges(opt_state_t *, struct block *);
#ifdef BDEBUG
-static void opt_dump(compiler_state_t *, struct icode *);
+static void opt_dump(opt_state_t *, struct icode *);
#endif
#ifndef MAX
x = opt_state->all_dom_sets;
i = opt_state->n_blocks * opt_state->nodewords;
while (--i >= 0)
- *x++ = ~0;
+ *x++ = 0xFFFFFFFFU;
/* Root starts off empty. */
for (i = opt_state->nodewords; --i >= 0;)
root->dom[i] = 0;
x = opt_state->all_edge_sets;
for (i = opt_state->n_edges * opt_state->edgewords; --i >= 0; )
- x[i] = ~0;
+ x[i] = 0xFFFFFFFFU;
/* root->level is the highest level no found. */
memset(root->et.edom, 0, opt_state->edgewords * sizeof(*(uset)0));
}
/*
- * Return the register number that is used by s. If A and X are both
- * used, return AX_ATOM. If no register is used, return -1.
+ * Return the register number that is used by s.
+ *
+ * Returns ATOM_A if A is used, ATOM_X if X is used, AX_ATOM if both A and X
+ * are used, the scratch memory location's number if a scratch memory
+ * location is used (e.g., 0 for M[0]), or -1 if none of those are used.
*
* The implementation should probably change to an array access.
*/
case BPF_LD:
case BPF_LDX:
+ /*
+ * As there are fewer than 2^31 memory locations,
+ * s->k should be convertable to int without problems.
+ */
return (BPF_MODE(c) == BPF_IND) ? X_ATOM :
- (BPF_MODE(c) == BPF_MEM) ? s->k : -1;
+ (BPF_MODE(c) == BPF_MEM) ? (int)s->k : -1;
case BPF_ST:
return A_ATOM;
memset((char *)opt_state->hashtbl, 0, sizeof opt_state->hashtbl);
}
-/* Because we really don't have an IR, this stuff is a little messy. */
-static int
-F(opt_state_t *opt_state, int code, int v0, int v1)
+/*
+ * Because we really don't have an IR, this stuff is a little messy.
+ *
+ * This routine looks in the table of existing value number for a value
+ * with generated from an operation with the specified opcode and
+ * the specified values. If it finds it, it returns its value number,
+ * otherwise it makes a new entry in the table and returns the
+ * value number of that entry.
+ */
+static bpf_u_int32
+F(opt_state_t *opt_state, int code, bpf_u_int32 v0, bpf_u_int32 v1)
{
u_int hash;
- int val;
+ bpf_u_int32 val;
struct valnode *p;
hash = (u_int)code ^ (v0 << 4) ^ (v1 << 8);
if (p->code == code && p->v0 == v0 && p->v1 == v1)
return p->val;
+ /*
+ * Not found. Allocate a new value, and assign it a new
+ * value number.
+ *
+ * opt_state->curval starts out as 0, which means VAL_UNKNOWN; we
+ * increment it before using it as the new value number, which
+ * means we never assign VAL_UNKNOWN.
+ *
+ * XXX - unless we overflow, but we probably won't have 2^32-1
+ * values; we treat 32 bits as effectively infinite.
+ */
val = ++opt_state->curval;
if (BPF_MODE(code) == BPF_IMM &&
(BPF_CLASS(code) == BPF_LD || BPF_CLASS(code) == BPF_LDX)) {
}
static inline void
-vstore(struct stmt *s, int *valp, int newval, int alter)
+vstore(struct stmt *s, bpf_u_int32 *valp, bpf_u_int32 newval, int alter)
{
if (alter && newval != VAL_UNKNOWN && *valp == newval)
s->code = NOP;
* (Unary operators are handled elsewhere.)
*/
static void
-fold_op(compiler_state_t *cstate, struct icode *ic, opt_state_t *opt_state,
- struct stmt *s, int v0, int v1)
+fold_op(opt_state_t *opt_state, struct stmt *s, bpf_u_int32 v0, bpf_u_int32 v1)
{
bpf_u_int32 a, b;
case BPF_DIV:
if (b == 0)
- bpf_error(cstate, "division by zero");
+ opt_error(opt_state, "division by zero");
a /= b;
break;
case BPF_MOD:
if (b == 0)
- bpf_error(cstate, "modulus by zero");
+ opt_error(opt_state, "modulus by zero");
a %= b;
break;
break;
case BPF_LSH:
- a <<= b;
+ /*
+ * A left shift of more than the width of the type
+ * is undefined in C; we'll just treat it as shifting
+ * all the bits out.
+ *
+ * XXX - the BPF interpreter doesn't check for this,
+ * so its behavior is dependent on the behavior of
+ * the processor on which it's running. There are
+ * processors on which it shifts all the bits out
+ * and processors on which it does no shift.
+ */
+ if (b < 32)
+ a <<= b;
+ else
+ a = 0;
break;
case BPF_RSH:
- a >>= b;
+ /*
+ * A right shift of more than the width of the type
+ * is undefined in C; we'll just treat it as shifting
+ * all the bits out.
+ *
+ * XXX - the BPF interpreter doesn't check for this,
+ * so its behavior is dependent on the behavior of
+ * the processor on which it's running. There are
+ * processors on which it shifts all the bits out
+ * and processors on which it does no shift.
+ */
+ if (b < 32)
+ a >>= b;
+ else
+ a = 0;
break;
default:
{
struct slist *s;
struct slist *next, *last;
- int val;
+ bpf_u_int32 val;
s = b->stmts;
if (s == 0)
if (b->s.code == (BPF_JMP|BPF_K|BPF_JSET)) {
if (b->s.k == 0)
JT(b) = JF(b);
- if ((u_int)b->s.k == 0xffffffffU)
+ if (b->s.k == 0xffffffffU)
JF(b) = JT(b);
}
/*
*/
val = b->val[X_ATOM];
if (opt_state->vmap[val].is_const && BPF_SRC(b->s.code) == BPF_X) {
- bpf_int32 v = opt_state->vmap[val].const_val;
+ bpf_u_int32 v = opt_state->vmap[val].const_val;
b->s.code &= ~BPF_X;
b->s.k = v;
}
*/
val = b->val[A_ATOM];
if (opt_state->vmap[val].is_const && BPF_SRC(b->s.code) == BPF_K) {
- bpf_int32 v = opt_state->vmap[val].const_val;
+ bpf_u_int32 v = opt_state->vmap[val].const_val;
switch (BPF_OP(b->s.code)) {
case BPF_JEQ:
break;
case BPF_JGT:
- v = (unsigned)v > (unsigned)b->s.k;
+ v = v > b->s.k;
break;
case BPF_JGE:
- v = (unsigned)v >= (unsigned)b->s.k;
+ v = v >= b->s.k;
break;
case BPF_JSET:
* evaluation and code transformations weren't folded together.
*/
static void
-opt_stmt(compiler_state_t *cstate, struct icode *ic, opt_state_t *opt_state,
- struct stmt *s, int val[], int alter)
+opt_stmt(opt_state_t *opt_state, struct stmt *s, bpf_u_int32 val[], int alter)
{
int op;
- int v;
+ bpf_u_int32 v;
switch (s->code) {
case BPF_ALU|BPF_NEG:
if (alter && opt_state->vmap[val[A_ATOM]].is_const) {
s->code = BPF_LD|BPF_IMM;
- s->k = -opt_state->vmap[val[A_ATOM]].const_val;
+ /*
+ * Do this negation as unsigned arithmetic; that's
+ * what modern BPF engines do, and it guarantees
+ * that all possible values can be negated. (Yeah,
+ * negating 0x80000000, the minimum signed 32-bit
+ * two's-complement value, results in 0x80000000,
+ * so it's still negative, but we *should* be doing
+ * all unsigned arithmetic here, to match what
+ * modern BPF engines do.)
+ *
+ * Express it as 0U - (unsigned value) so that we
+ * don't get compiler warnings about negating an
+ * unsigned value and don't get UBSan warnings
+ * about the result of negating 0x80000000 being
+ * undefined.
+ */
+ s->k = 0U - opt_state->vmap[val[A_ATOM]].const_val;
val[A_ATOM] = K(s->k);
}
else
op = BPF_OP(s->code);
if (alter) {
if (s->k == 0) {
- /* don't optimize away "sub #0"
+ /*
+ * Optimize operations where the constant
+ * is zero.
+ *
+ * Don't optimize away "sub #0"
* as it may be needed later to
- * fixup the generated math code */
+ * fixup the generated math code.
+ *
+ * Fail if we're dividing by zero or taking
+ * a modulus by zero.
+ */
if (op == BPF_ADD ||
op == BPF_LSH || op == BPF_RSH ||
op == BPF_OR || op == BPF_XOR) {
val[A_ATOM] = K(s->k);
break;
}
+ if (op == BPF_DIV)
+ opt_error(opt_state,
+ "division by zero");
+ if (op == BPF_MOD)
+ opt_error(opt_state,
+ "modulus by zero");
}
if (opt_state->vmap[val[A_ATOM]].is_const) {
- fold_op(cstate, ic, opt_state, s, val[A_ATOM], K(s->k));
+ fold_op(opt_state, s, val[A_ATOM], K(s->k));
val[A_ATOM] = K(s->k);
break;
}
op = BPF_OP(s->code);
if (alter && opt_state->vmap[val[X_ATOM]].is_const) {
if (opt_state->vmap[val[A_ATOM]].is_const) {
- fold_op(cstate, ic, opt_state, s, val[A_ATOM], val[X_ATOM]);
+ fold_op(opt_state, s, val[A_ATOM], val[X_ATOM]);
val[A_ATOM] = K(s->k);
}
else {
s->code = BPF_ALU|BPF_K|op;
s->k = opt_state->vmap[val[X_ATOM]].const_val;
+ if ((op == BPF_LSH || op == BPF_RSH) &&
+ s->k > 31)
+ opt_error(opt_state,
+ "shift by more than 31 bits");
opt_state->done = 0;
val[A_ATOM] =
F(opt_state, s->code, val[A_ATOM], K(s->k));
}
static void
-opt_blk(compiler_state_t *cstate, struct icode *ic, opt_state_t *opt_state,
- struct block *b, int do_stmts)
+opt_blk(opt_state_t *opt_state, struct block *b, int do_stmts)
{
struct slist *s;
struct edge *p;
int i;
- bpf_int32 aval, xval;
+ bpf_u_int32 aval, xval;
#if 0
for (s = b->stmts; s && s->next; s = s->next)
aval = b->val[A_ATOM];
xval = b->val[X_ATOM];
for (s = b->stmts; s; s = s->next)
- opt_stmt(cstate, ic, opt_state, &s->s, b->val, do_stmts);
+ opt_stmt(opt_state, &s->s, b->val, do_stmts);
/*
* This is a special case: if we don't use anything from this
fold_edge(struct block *child, struct edge *ep)
{
int sense;
- int aval0, aval1, oval0, oval1;
+ bpf_u_int32 aval0, aval1, oval0, oval1;
int code = ep->code;
if (code < 0) {
while (x != 0) {
k = lowest_set_bit(x);
- x &=~ (1 << k);
+ x &=~ ((bpf_u_int32)1 << k);
k += i * BITS_PER_WORD;
target = fold_edge(ep->succ, opt_state->edges[k]);
static void
or_pullup(opt_state_t *opt_state, struct block *b)
{
- int val, at_top;
+ bpf_u_int32 val;
+ int at_top;
struct block *pull;
struct block **diffp, **samep;
struct edge *ep;
diffp = &JF(b->in_edges->pred);
at_top = 1;
- while (1) {
+ for (;;) {
if (*diffp == 0)
return;
at_top = 0;
}
samep = &JF(*diffp);
- while (1) {
+ for (;;) {
if (*samep == 0)
return;
static void
and_pullup(opt_state_t *opt_state, struct block *b)
{
- int val, at_top;
+ bpf_u_int32 val;
+ int at_top;
struct block *pull;
struct block **diffp, **samep;
struct edge *ep;
diffp = &JF(b->in_edges->pred);
at_top = 1;
- while (1) {
+ for (;;) {
if (*diffp == 0)
return;
at_top = 0;
}
samep = &JT(*diffp);
- while (1) {
+ for (;;) {
if (*samep == 0)
return;
}
static void
-opt_blks(compiler_state_t *cstate, opt_state_t *opt_state, struct icode *ic,
- int do_stmts)
+opt_blks(opt_state_t *opt_state, struct icode *ic, int do_stmts)
{
int i, maxlevel;
struct block *p;
find_inedges(opt_state, ic->root);
for (i = maxlevel; i >= 0; --i)
for (p = opt_state->levels[i]; p; p = p->link)
- opt_blk(cstate, ic, opt_state, p, do_stmts);
+ opt_blk(opt_state, p, do_stmts);
if (do_stmts)
/*
}
static void
-opt_loop(compiler_state_t *cstate, opt_state_t *opt_state, struct icode *ic,
- int do_stmts)
+opt_loop(opt_state_t *opt_state, struct icode *ic, int do_stmts)
{
#ifdef BDEBUG
- if (pcap_optimizer_debug > 1) {
+ if (pcap_optimizer_debug > 1 || pcap_print_dot_graph) {
printf("opt_loop(root, %d) begin\n", do_stmts);
- opt_dump(cstate, ic);
+ opt_dump(opt_state, ic);
}
#endif
do {
find_closure(opt_state, ic->root);
find_ud(opt_state, ic->root);
find_edom(opt_state, ic->root);
- opt_blks(cstate, opt_state, ic, do_stmts);
+ opt_blks(opt_state, ic, do_stmts);
#ifdef BDEBUG
- if (pcap_optimizer_debug > 1) {
+ if (pcap_optimizer_debug > 1 || pcap_print_dot_graph) {
printf("opt_loop(root, %d) bottom, done=%d\n", do_stmts, opt_state->done);
- opt_dump(cstate, ic);
+ opt_dump(opt_state, ic);
}
#endif
} while (!opt_state->done);
/*
* Optimize the filter code in its dag representation.
+ * Return 0 on success, -1 on error.
*/
-void
-bpf_optimize(compiler_state_t *cstate, struct icode *ic)
+int
+bpf_optimize(struct icode *ic, char *errbuf)
{
opt_state_t opt_state;
- opt_init(cstate, &opt_state, ic);
- opt_loop(cstate, &opt_state, ic, 0);
- opt_loop(cstate, &opt_state, ic, 1);
+ memset(&opt_state, 0, sizeof(opt_state));
+ opt_state.errbuf = errbuf;
+ if (setjmp(opt_state.top_ctx)) {
+ opt_cleanup(&opt_state);
+ return -1;
+ }
+ opt_init(&opt_state, ic);
+ opt_loop(&opt_state, ic, 0);
+ opt_loop(&opt_state, ic, 1);
intern_blocks(&opt_state, ic);
#ifdef BDEBUG
- if (pcap_optimizer_debug > 1) {
+ if (pcap_optimizer_debug > 1 || pcap_print_dot_graph) {
printf("after intern_blocks()\n");
- opt_dump(cstate, ic);
+ opt_dump(&opt_state, ic);
}
#endif
opt_root(&ic->root);
#ifdef BDEBUG
- if (pcap_optimizer_debug > 1) {
+ if (pcap_optimizer_debug > 1 || pcap_print_dot_graph) {
printf("after opt_root()\n");
- opt_dump(cstate, ic);
+ opt_dump(&opt_state, ic);
}
#endif
opt_cleanup(&opt_state);
+ return 0;
}
static void
static int
eq_slist(struct slist *x, struct slist *y)
{
- while (1) {
+ for (;;) {
while (x && x->s.code == NOP)
x = x->next;
while (y && y->s.code == NOP)
free((void *)opt_state->blocks);
}
+/*
+ * For optimizer errors.
+ */
+static void PCAP_NORETURN
+opt_error(opt_state_t *opt_state, const char *fmt, ...)
+{
+ va_list ap;
+
+ if (opt_state->errbuf != NULL) {
+ va_start(ap, fmt);
+ (void)vsnprintf(opt_state->errbuf,
+ PCAP_ERRBUF_SIZE, fmt, ap);
+ va_end(ap);
+ }
+ longjmp(opt_state->top_ctx, 1);
+ /* NOTREACHED */
+}
+
/*
* Return the number of stmts in 's'.
*/
* from the total number of blocks and/or statements.
*/
static void
-opt_init(compiler_state_t *cstate, opt_state_t *opt_state, struct icode *ic)
+opt_init(opt_state_t *opt_state, struct icode *ic)
{
bpf_u_int32 *p;
int i, n, max_stmts;
n = count_blocks(ic, ic->root);
opt_state->blocks = (struct block **)calloc(n, sizeof(*opt_state->blocks));
if (opt_state->blocks == NULL)
- bpf_error(cstate, "malloc");
+ opt_error(opt_state, "malloc");
unMarkAll(ic);
opt_state->n_blocks = 0;
number_blks_r(opt_state, ic, ic->root);
opt_state->n_edges = 2 * opt_state->n_blocks;
opt_state->edges = (struct edge **)calloc(opt_state->n_edges, sizeof(*opt_state->edges));
- if (opt_state->edges == NULL)
- bpf_error(cstate, "malloc");
+ if (opt_state->edges == NULL) {
+ opt_error(opt_state, "malloc");
+ }
/*
* The number of levels is bounded by the number of nodes.
*/
opt_state->levels = (struct block **)calloc(opt_state->n_blocks, sizeof(*opt_state->levels));
- if (opt_state->levels == NULL)
- bpf_error(cstate, "malloc");
+ if (opt_state->levels == NULL) {
+ opt_error(opt_state, "malloc");
+ }
opt_state->edgewords = opt_state->n_edges / (8 * sizeof(bpf_u_int32)) + 1;
opt_state->nodewords = opt_state->n_blocks / (8 * sizeof(bpf_u_int32)) + 1;
/* 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));
- if (opt_state->space == NULL)
- bpf_error(cstate, "malloc");
+ if (opt_state->space == NULL) {
+ opt_error(opt_state, "malloc");
+ }
p = opt_state->space;
opt_state->all_dom_sets = p;
for (i = 0; i < n; ++i) {
*/
opt_state->maxval = 3 * max_stmts;
opt_state->vmap = (struct vmapinfo *)calloc(opt_state->maxval, sizeof(*opt_state->vmap));
+ if (opt_state->vmap == NULL) {
+ opt_error(opt_state, "malloc");
+ }
opt_state->vnode_base = (struct valnode *)calloc(opt_state->maxval, sizeof(*opt_state->vnode_base));
- if (opt_state->vmap == NULL || opt_state->vnode_base == NULL)
- bpf_error(cstate, "malloc");
+ if (opt_state->vnode_base == NULL) {
+ opt_error(opt_state, "malloc");
+ }
}
/*
* and expect it to provide meaningful information.
*/
#ifdef BDEBUG
-int bids[1000];
+int bids[NBIDS];
#endif
+static void PCAP_NORETURN conv_error(conv_state_t *, const char *, ...)
+ PCAP_PRINTFLIKE(2, 3);
+
/*
* Returns true if successful. Returns false if a branch has
* an offset that is too large. If so, we have marked that
* properly.
*/
static int
-convert_code_r(compiler_state_t *cstate, conv_state_t *conv_state,
- struct icode *ic, struct block *p)
+convert_code_r(conv_state_t *conv_state, struct icode *ic, struct block *p)
{
struct bpf_insn *dst;
struct slist *src;
u_int slen;
u_int off;
- int extrajmps; /* number of extra jumps inserted */
+ u_int extrajmps; /* number of extra jumps inserted */
struct slist **offset = NULL;
if (p == 0 || isMarked(ic, p))
return (1);
Mark(ic, p);
- if (convert_code_r(cstate, conv_state, ic, JF(p)) == 0)
+ if (convert_code_r(conv_state, ic, JF(p)) == 0)
return (0);
- if (convert_code_r(cstate, conv_state, ic, JT(p)) == 0)
+ if (convert_code_r(conv_state, ic, JT(p)) == 0)
return (0);
slen = slength(p->stmts);
if (slen) {
offset = (struct slist **)calloc(slen, sizeof(struct slist *));
if (!offset) {
- bpf_error(cstate, "not enough core");
+ conv_error(conv_state, "not enough core");
/*NOTREACHED*/
}
}
if (BPF_CLASS(src->s.code) != BPF_JMP || src->s.code == (BPF_JMP|BPF_JA)) {
#if 0
if (src->s.jt || src->s.jf) {
- bpf_error(cstate, "illegal jmp destination");
+ free(offset);
+ conv_error(conv_state, "illegal jmp destination");
/*NOTREACHED*/
}
#endif
{
u_int i;
int jt, jf;
- const char *ljerr = "%s for block-local relative jump: off=%d";
+ const char ljerr[] = "%s for block-local relative jump: off=%d";
#if 0
printf("code=%x off=%d %x %x\n", src->s.code,
#endif
if (!src->s.jt || !src->s.jf) {
- bpf_error(cstate, ljerr, "no jmp destination", off);
+ free(offset);
+ conv_error(conv_state, ljerr, "no jmp destination", off);
/*NOTREACHED*/
}
for (i = 0; i < slen; i++) {
if (offset[i] == src->s.jt) {
if (jt) {
- bpf_error(cstate, ljerr, "multiple matches", off);
+ free(offset);
+ conv_error(conv_state, ljerr, "multiple matches", off);
/*NOTREACHED*/
}
- dst->jt = i - off - 1;
+ if (i - off - 1 >= 256) {
+ free(offset);
+ conv_error(conv_state, ljerr, "out-of-range jump", off);
+ /*NOTREACHED*/
+ }
+ dst->jt = (u_char)(i - off - 1);
jt++;
}
if (offset[i] == src->s.jf) {
if (jf) {
- bpf_error(cstate, ljerr, "multiple matches", off);
+ free(offset);
+ conv_error(conv_state, ljerr, "multiple matches", off);
/*NOTREACHED*/
}
- dst->jf = i - off - 1;
+ if (i - off - 1 >= 256) {
+ free(offset);
+ conv_error(conv_state, ljerr, "out-of-range jump", off);
+ /*NOTREACHED*/
+ }
+ dst->jf = (u_char)(i - off - 1);
jf++;
}
}
if (!jt || !jf) {
- bpf_error(cstate, ljerr, "no destination found", off);
+ free(offset);
+ conv_error(conv_state, ljerr, "no destination found", off);
/*NOTREACHED*/
}
}
free(offset);
#ifdef BDEBUG
- bids[dst - conv_state->fstart] = p->id + 1;
+ if (dst - conv_state->fstart < NBIDS)
+ bids[dst - conv_state->fstart] = p->id + 1;
#endif
dst->code = (u_short)p->s.code;
dst->k = p->s.k;
return(0);
}
/* branch if T to following jump */
- dst->jt = extrajmps;
+ if (extrajmps >= 256) {
+ conv_error(conv_state, "too many extra jumps");
+ /*NOTREACHED*/
+ }
+ dst->jt = (u_char)extrajmps;
extrajmps++;
dst[extrajmps].code = BPF_JMP|BPF_JA;
dst[extrajmps].k = off - extrajmps;
}
else
- dst->jt = off;
+ dst->jt = (u_char)off;
off = JF(p)->offset - (p->offset + slen) - 1;
if (off >= 256) {
/* offset too large for branch, must add a jump */
}
/* branch if F to following jump */
/* if two jumps are inserted, F goes to second one */
- dst->jf = extrajmps;
+ if (extrajmps >= 256) {
+ conv_error(conv_state, "too many extra jumps");
+ /*NOTREACHED*/
+ }
+ dst->jf = (u_char)extrajmps;
extrajmps++;
dst[extrajmps].code = BPF_JMP|BPF_JA;
dst[extrajmps].k = off - extrajmps;
}
else
- dst->jf = off;
+ dst->jf = (u_char)off;
}
return (1);
}
* done with the filter program. See the pcap man page.
*/
struct bpf_insn *
-icode_to_fcode(compiler_state_t *cstate, struct icode *ic,
- struct block *root, u_int *lenp)
+icode_to_fcode(struct icode *ic, struct block *root, u_int *lenp,
+ char *errbuf)
{
u_int n;
struct bpf_insn *fp;
conv_state_t conv_state;
+ conv_state.fstart = NULL;
+ conv_state.errbuf = errbuf;
+ if (setjmp(conv_state.top_ctx) != 0) {
+ free(conv_state.fstart);
+ return NULL;
+ }
+
/*
* Loop doing convert_code_r() until no branches remain
* with too-large offsets.
*/
- while (1) {
+ for (;;) {
unMarkAll(ic);
n = *lenp = count_stmts(ic, root);
fp = (struct bpf_insn *)malloc(sizeof(*fp) * n);
- if (fp == NULL)
- bpf_error(cstate, "malloc");
+ if (fp == NULL) {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "malloc");
+ free(fp);
+ return NULL;
+ }
memset((char *)fp, 0, sizeof(*fp) * n);
conv_state.fstart = fp;
conv_state.ftail = fp + n;
unMarkAll(ic);
- if (convert_code_r(cstate, &conv_state, ic, root))
+ if (convert_code_r(&conv_state, ic, root))
break;
free(fp);
}
return fp;
}
+/*
+ * For iconv_to_fconv() errors.
+ */
+static void PCAP_NORETURN
+conv_error(conv_state_t *conv_state, const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ (void)vsnprintf(conv_state->errbuf,
+ PCAP_ERRBUF_SIZE, fmt, ap);
+ va_end(ap);
+ longjmp(conv_state->top_ctx, 1);
+ /* NOTREACHED */
+}
+
/*
* Make a copy of a BPF program and put it in the "fcode" member of
* a "pcap_t".
/*
* Validate the program.
*/
- if (!bpf_validate(fp->bf_insns, fp->bf_len)) {
- pcap_snprintf(p->errbuf, sizeof(p->errbuf),
+ if (!pcap_validate_filter(fp->bf_insns, fp->bf_len)) {
+ snprintf(p->errbuf, sizeof(p->errbuf),
"BPF program is not valid");
return (-1);
}
* After install graphviz on http://www.graphviz.org/, save it as bpf.dot
* and run `dot -Tpng -O bpf.dot' to draw the graph.
*/
-static void
-dot_dump(compiler_state_t *cstate, struct icode *ic)
+static int
+dot_dump(struct icode *ic, char *errbuf)
{
struct bpf_program f;
FILE *out = stdout;
memset(bids, 0, sizeof bids);
- f.bf_insns = icode_to_fcode(cstate, ic, ic->root, &f.bf_len);
+ f.bf_insns = icode_to_fcode(ic, ic->root, &f.bf_len, errbuf);
+ if (f.bf_insns == NULL)
+ return -1;
fprintf(out, "digraph BPF {\n");
unMarkAll(ic);
fprintf(out, "}\n");
free((char *)f.bf_insns);
+ return 0;
}
-static void
-plain_dump(compiler_state_t *cstate, struct icode *ic)
+static int
+plain_dump(struct icode *ic, char *errbuf)
{
struct bpf_program f;
memset(bids, 0, sizeof bids);
- f.bf_insns = icode_to_fcode(cstate, ic, ic->root, &f.bf_len);
+ f.bf_insns = icode_to_fcode(ic, ic->root, &f.bf_len, errbuf);
+ if (f.bf_insns == NULL)
+ return -1;
bpf_dump(&f, 1);
putchar('\n');
free((char *)f.bf_insns);
+ return 0;
}
static void
-opt_dump(compiler_state_t *cstate, struct icode *ic)
+opt_dump(opt_state_t *opt_state, struct icode *ic)
{
- /* if optimizer debugging is enabled, output DOT graph
- * `pcap_optimizer_debug=4' is equivalent to -dddd to follow -d/-dd/-ddd
- * convention in tcpdump command line
+ int status;
+ char errbuf[PCAP_ERRBUF_SIZE];
+
+ /*
+ * If the CFG, in DOT format, is requested, output it rather than
+ * the code that would be generated from that graph.
*/
- if (pcap_optimizer_debug > 3)
- dot_dump(cstate, ic);
+ if (pcap_print_dot_graph)
+ status = dot_dump(ic, errbuf);
else
- plain_dump(cstate, ic);
+ status = plain_dump(ic, errbuf);
+ if (status == -1)
+ opt_error(opt_state, "opt_dump: icode_to_fcode failed: %s", errbuf);
}
#endif
projects / libpcap / blobdiff