In the open request, reject capture sources that are URLs.

[libpcap] / optimize.c

diff --git a/optimize.c b/optimize.c
index 4beb90f88085b33c7d84803d1f72d35c111487d4..283a6de30fa3f6b99f576cc043a68b98a6722e34 100644 (file)
--- a/optimize.c
+++ b/optimize.c
@@ -18,7 +18,7 @@
  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *

- *  Optimization module for tcpdump intermediate representation.
+ *  Optimization module for BPF code intermediate representation.

  */
 
 #ifdef HAVE_CONFIG_H
  */
 
 #ifdef HAVE_CONFIG_H


@@ -30,6 +30,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <memory.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <memory.h>

+#include <setjmp.h>

 #include <string.h>
 
 #include <errno.h>
 #include <string.h>
 
 #include <errno.h>


@@ -37,39 +38,149 @@
 #include "pcap-int.h"
 
 #include "gencode.h"
 #include "pcap-int.h"
 
 #include "gencode.h"

+#include "optimize.h"

 
 #ifdef HAVE_OS_PROTO_H
 #include "os-proto.h"
 #endif
 
 #ifdef BDEBUG
 
 #ifdef HAVE_OS_PROTO_H
 #include "os-proto.h"
 #endif
 
 #ifdef BDEBUG

-int pcap_optimizer_debug;
-#endif
+/*
+ * 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;

 
 

-#if defined(MSDOS) && !defined(__DJGPP__)
-extern int _w32_ffs (int mask);
-#define ffs _w32_ffs
-#endif
+/*
+ * 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;
+}

 
 /*
 
 /*

- * So is the check for _MSC_VER done because MinGW has this?
+ * 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.

  */
  */

-#if defined(_WIN32) && defined (_MSC_VER)
+static int pcap_print_dot_graph;
+

 /*
 /*

- * ffs -- vax ffs instruction
+ * Routine to set that flag.

  *
  *

- * XXX - with versions of VS that have it, use _BitScanForward()?
+ * 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
+
+/*
+ * lowest_set_bit().
+ *
+ * Takes a 32-bit integer as an argument.
+ *
+ * If handed a non-zero value, returns the index of the lowest set bit,
+ * counting upwards fro zero.
+ *
+ * If handed zero, the results are platform- and compiler-dependent.
+ * Keep it out of the light, don't give it any water, don't feed it
+ * after midnight, and don't pass zero to it.
+ *
+ * This is the same as the count of trailing zeroes in the word.
+ */
+#if PCAP_IS_AT_LEAST_GNUC_VERSION(3,4)
+  /*
+   * GCC 3.4 and later; we have __builtin_ctz().
+   */
+  #define lowest_set_bit(mask) __builtin_ctz(mask)
+#elif defined(_MSC_VER)
+  /*
+   * Visual Studio; we support only 2005 and later, so use
+   * _BitScanForward().
+   */
+#include <intrin.h>
+
+#ifndef __clang__
+#pragma intrinsic(_BitScanForward)
+#endif
+
+static __forceinline int
+lowest_set_bit(int mask)
+{
+       unsigned long bit;
+
+       /*
+        * Don't sign-extend mask if long is longer than int.
+        * (It's currently not, in MSVC, even on 64-bit platforms, but....)
+        */
+       if (_BitScanForward(&bit, (unsigned int)mask) == 0)
+               return -1;      /* mask is zero */
+       return (int)bit;
+}
+#elif defined(MSDOS) && defined(__DJGPP__)
+  /*
+   * MS-DOS with DJGPP, which declares ffs() in <string.h>, which
+   * we've already included.
+   */
+  #define lowest_set_bit(mask) (ffs((mask)) - 1)
+#elif (defined(MSDOS) && defined(__WATCOMC__)) || defined(STRINGS_H_DECLARES_FFS)
+  /*
+   * MS-DOS with Watcom C, which has <strings.h> and declares ffs() there,
+   * or some other platform (UN*X conforming to a sufficient recent version
+   * of the Single UNIX Specification).
+   */
+  #include <strings.h>
+  #define lowest_set_bit(mask) (ffs((mask)) - 1)
+#else
+/*
+ * None of the above.
+ * Use a perfect-hash-function-based function.

  */
 static int
  */
 static int

-ffs(int mask)
+lowest_set_bit(int mask)

 {
 {

-       int bit;
+       unsigned int v = (unsigned int)mask;
+
+       static const int MultiplyDeBruijnBitPosition[32] = {
+               0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
+               31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
+       };

 
 

-       if (mask == 0)
-               return(0);
-       for (bit = 1; !(mask & 1); bit++)
-               mask >>= 1;
-       return(bit);
+       /*
+        * We strip off all but the lowermost set bit (v & ~v),
+        * and perform a minimal perfect hash on it to look up the
+        * number of low-order zero bits in a table.
+        *
+        * See:
+        *
+        *      http://7ooo.mooo.com/text/ComputingTrailingZerosHOWTO.pdf
+        *
+        *      http://supertech.csail.mit.edu/papers/debruijn.pdf
+        */
+       return (MultiplyDeBruijnBitPosition[((v & -v) * 0x077CB531U) >> 27]);

 }
 #endif
 
 }
 #endif
 


@@ -102,20 +213,30 @@ ffs(int mask)
  */
 struct valnode {
        int code;
  */
 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. */
        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;
 
 struct vmapinfo {
        int is_const;

-       bpf_int32 const_val;
+       bpf_u_int32 const_val;

 };
 
 typedef struct {
 };
 
 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
        /*
         * A flag to indicate that further optimization is needed.
         * Iterative passes are continued until a given pass yields no


@@ -142,19 +263,19 @@ typedef struct {
  * True if a is in uset {p}
  */
 #define SET_MEMBER(p, a) \
  * 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) \
 
 /*
  * 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) \
 
 /*
  * 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
 
 /*
  * a := a intersect b


@@ -192,8 +313,8 @@ typedef struct {
 
 #define MODULUS 213
        struct valnode *hashtbl[MODULUS];
 
 #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;
 
        struct vmapinfo *vmap;
        struct valnode *vnode_base;


@@ -201,6 +322,16 @@ typedef struct {
 } opt_state_t;
 
 typedef struct {
 } 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
        /*
         * Some pointers used to convert the basic block form of the code,
         * into the array form that BPF requires.  'fstart' will point to


@@ -211,14 +342,16 @@ typedef struct {
        struct bpf_insn *ftail;
 } conv_state_t;
 
        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 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 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
 #endif
 
 #ifndef MAX


@@ -278,7 +411,7 @@ find_dom(opt_state_t *opt_state, struct block *root)
        x = opt_state->all_dom_sets;
        i = opt_state->n_blocks * opt_state->nodewords;
        while (--i >= 0)
        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;
        /* Root starts off empty. */
        for (i = opt_state->nodewords; --i >= 0;)
                root->dom[i] = 0;


@@ -318,7 +451,7 @@ find_edom(opt_state_t *opt_state, struct block *root)
 
        x = opt_state->all_edge_sets;
        for (i = opt_state->n_edges * opt_state->edgewords; --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));
 
        /* root->level is the highest level no found. */
        memset(root->et.edom, 0, opt_state->edgewords * sizeof(*(uset)0));


@@ -363,8 +496,11 @@ find_closure(opt_state_t *opt_state, struct block *root)
 }
 
 /*
 }
 
 /*

- * 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.
  */
  *
  * The implementation should probably change to an array access.
  */


@@ -384,8 +520,12 @@ atomuse(struct stmt *s)
 
        case BPF_LD:
        case BPF_LDX:
 
        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 :
                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;
 
        case BPF_ST:
                return A_ATOM;


@@ -543,12 +683,20 @@ init_val(opt_state_t *opt_state)
        memset((char *)opt_state->hashtbl, 0, sizeof opt_state->hashtbl);
 }
 
        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;
 {
        u_int hash;

-       int val;
+       bpf_u_int32 val;

        struct valnode *p;
 
        hash = (u_int)code ^ (v0 << 4) ^ (v1 << 8);
        struct valnode *p;
 
        hash = (u_int)code ^ (v0 << 4) ^ (v1 << 8);


@@ -558,6 +706,17 @@ F(opt_state_t *opt_state, int code, int v0, int v1)
                if (p->code == code && p->v0 == v0 && p->v1 == v1)
                        return p->val;
 
                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)) {
        val = ++opt_state->curval;
        if (BPF_MODE(code) == BPF_IMM &&
            (BPF_CLASS(code) == BPF_LD || BPF_CLASS(code) == BPF_LDX)) {


@@ -576,7 +735,7 @@ F(opt_state_t *opt_state, int code, int v0, int v1)
 }
 
 static inline void
 }
 
 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;
 {
        if (alter && newval != VAL_UNKNOWN && *valp == newval)
                s->code = NOP;


@@ -589,8 +748,7 @@ vstore(struct stmt *s, int *valp, int newval, int alter)
  * (Unary operators are handled elsewhere.)
  */
 static void
  * (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;
 
 {
        bpf_u_int32 a, b;
 


@@ -612,13 +770,13 @@ fold_op(compiler_state_t *cstate, struct icode *ic, opt_state_t *opt_state,
 
        case BPF_DIV:
                if (b == 0)
 
        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)
                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;
 
                a %= b;
                break;
 


@@ -635,11 +793,39 @@ fold_op(compiler_state_t *cstate, struct icode *ic, opt_state_t *opt_state,
                break;
 
        case BPF_LSH:
                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:
                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:
                break;
 
        default:


@@ -672,7 +858,7 @@ opt_peep(opt_state_t *opt_state, struct block *b)
 {
        struct slist *s;
        struct slist *next, *last;
 {
        struct slist *s;
        struct slist *next, *last;

-       int val;
+       bpf_u_int32 val;

 
        s = b->stmts;
        if (s == 0)
 
        s = b->stmts;
        if (s == 0)


@@ -873,7 +1059,7 @@ opt_peep(opt_state_t *opt_state, struct block *b)
        if (b->s.code == (BPF_JMP|BPF_K|BPF_JSET)) {
                if (b->s.k == 0)
                        JT(b) = JF(b);
        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);
        }
        /*
                        JF(b) = JT(b);
        }
        /*


@@ -883,7 +1069,7 @@ opt_peep(opt_state_t *opt_state, struct block *b)
         */
        val = b->val[X_ATOM];
        if (opt_state->vmap[val].is_const && BPF_SRC(b->s.code) == BPF_X) {
         */
        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;
        }
                b->s.code &= ~BPF_X;
                b->s.k = v;
        }


@@ -893,7 +1079,7 @@ opt_peep(opt_state_t *opt_state, struct block *b)
         */
        val = b->val[A_ATOM];
        if (opt_state->vmap[val].is_const && BPF_SRC(b->s.code) == BPF_K) {
         */
        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:
                switch (BPF_OP(b->s.code)) {
 
                case BPF_JEQ:


@@ -901,11 +1087,11 @@ opt_peep(opt_state_t *opt_state, struct block *b)
                        break;
 
                case BPF_JGT:
                        break;
 
                case BPF_JGT:

-                       v = (unsigned)v > (unsigned)b->s.k;
+                       v = v > b->s.k;

                        break;
 
                case BPF_JGE:
                        break;
 
                case BPF_JGE:

-                       v = (unsigned)v >= (unsigned)b->s.k;
+                       v = v >= b->s.k;

                        break;
 
                case BPF_JSET:
                        break;
 
                case BPF_JSET:


@@ -931,11 +1117,10 @@ opt_peep(opt_state_t *opt_state, struct block *b)
  * evaluation and code transformations weren't folded together.
  */
 static void
  * 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 op;

-       int v;
+       bpf_u_int32 v;

 
        switch (s->code) {
 
 
        switch (s->code) {
 


@@ -984,7 +1169,23 @@ opt_stmt(compiler_state_t *cstate, struct icode *ic, opt_state_t *opt_state,
        case BPF_ALU|BPF_NEG:
                if (alter && opt_state->vmap[val[A_ATOM]].is_const) {
                        s->code = BPF_LD|BPF_IMM;
        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
                        val[A_ATOM] = K(s->k);
                }
                else


@@ -1004,9 +1205,17 @@ opt_stmt(compiler_state_t *cstate, struct icode *ic, opt_state_t *opt_state,
                op = BPF_OP(s->code);
                if (alter) {
                        if (s->k == 0) {
                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
                                 * 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) {
                                if (op == BPF_ADD ||
                                    op == BPF_LSH || op == BPF_RSH ||
                                    op == BPF_OR || op == BPF_XOR) {


@@ -1018,9 +1227,15 @@ opt_stmt(compiler_state_t *cstate, struct icode *ic, opt_state_t *opt_state,
                                        val[A_ATOM] = K(s->k);
                                        break;
                                }
                                        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) {
                        }
                        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;
                        }
                                val[A_ATOM] = K(s->k);
                                break;
                        }


@@ -1041,12 +1256,16 @@ opt_stmt(compiler_state_t *cstate, struct icode *ic, opt_state_t *opt_state,
                op = BPF_OP(s->code);
                if (alter && opt_state->vmap[val[X_ATOM]].is_const) {
                        if (opt_state->vmap[val[A_ATOM]].is_const) {
                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;
                                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));
                                opt_state->done = 0;
                                val[A_ATOM] =
                                        F(opt_state, s->code, val[A_ATOM], K(s->k));


@@ -1165,13 +1384,12 @@ opt_deadstores(opt_state_t *opt_state, register struct block *b)
 }
 
 static void
 }
 
 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;
 {
        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)
 
 #if 0
        for (s = b->stmts; s && s->next; s = s->next)


@@ -1216,7 +1434,7 @@ opt_blk(compiler_state_t *cstate, struct icode *ic, opt_state_t *opt_state,
        aval = b->val[A_ATOM];
        xval = b->val[X_ATOM];
        for (s = b->stmts; s; 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
 
        /*
         * This is a special case: if we don't use anything from this


@@ -1290,7 +1508,7 @@ static struct block *
 fold_edge(struct block *child, struct edge *ep)
 {
        int sense;
 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) {
        int code = ep->code;
 
        if (code < 0) {


@@ -1369,8 +1587,8 @@ opt_j(opt_state_t *opt_state, struct edge *ep)
                register bpf_u_int32 x = ep->edom[i];
 
                while (x != 0) {
                register bpf_u_int32 x = ep->edom[i];
 
                while (x != 0) {

-                       k = ffs(x) - 1;
-                       x &=~ (1 << k);
+                       k = lowest_set_bit(x);
+                       x &=~ ((bpf_u_int32)1 << k);

                        k += i * BITS_PER_WORD;
 
                        target = fold_edge(ep->succ, opt_state->edges[k]);
                        k += i * BITS_PER_WORD;
 
                        target = fold_edge(ep->succ, opt_state->edges[k]);


@@ -1396,7 +1614,8 @@ opt_j(opt_state_t *opt_state, struct edge *ep)
 static void
 or_pullup(opt_state_t *opt_state, struct block *b)
 {
 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;
        struct block *pull;
        struct block **diffp, **samep;
        struct edge *ep;


@@ -1420,7 +1639,7 @@ or_pullup(opt_state_t *opt_state, struct block *b)
                diffp = &JF(b->in_edges->pred);
 
        at_top = 1;
                diffp = &JF(b->in_edges->pred);
 
        at_top = 1;

-       while (1) {
+       for (;;) {

                if (*diffp == 0)
                        return;
 
                if (*diffp == 0)
                        return;
 


@@ -1437,7 +1656,7 @@ or_pullup(opt_state_t *opt_state, struct block *b)
                at_top = 0;
        }
        samep = &JF(*diffp);
                at_top = 0;
        }
        samep = &JF(*diffp);

-       while (1) {
+       for (;;) {

                if (*samep == 0)
                        return;
 
                if (*samep == 0)
                        return;
 


@@ -1488,7 +1707,8 @@ or_pullup(opt_state_t *opt_state, struct block *b)
 static void
 and_pullup(opt_state_t *opt_state, struct block *b)
 {
 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;
        struct block *pull;
        struct block **diffp, **samep;
        struct edge *ep;


@@ -1511,7 +1731,7 @@ and_pullup(opt_state_t *opt_state, struct block *b)
                diffp = &JF(b->in_edges->pred);
 
        at_top = 1;
                diffp = &JF(b->in_edges->pred);
 
        at_top = 1;

-       while (1) {
+       for (;;) {

                if (*diffp == 0)
                        return;
 
                if (*diffp == 0)
                        return;
 


@@ -1528,7 +1748,7 @@ and_pullup(opt_state_t *opt_state, struct block *b)
                at_top = 0;
        }
        samep = &JT(*diffp);
                at_top = 0;
        }
        samep = &JT(*diffp);

-       while (1) {
+       for (;;) {

                if (*samep == 0)
                        return;
 
                if (*samep == 0)
                        return;
 


@@ -1577,8 +1797,7 @@ and_pullup(opt_state_t *opt_state, struct block *b)
 }
 
 static void
 }
 
 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;
 {
        int i, maxlevel;
        struct block *p;


@@ -1589,7 +1808,7 @@ opt_blks(compiler_state_t *cstate, opt_state_t *opt_state, struct icode *ic,
        find_inedges(opt_state, ic->root);
        for (i = maxlevel; i >= 0; --i)
                for (p = opt_state->levels[i]; p; p = p->link)
        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)
                /*
 
        if (do_stmts)
                /*


@@ -1667,14 +1886,13 @@ opt_root(struct block **b)
 }
 
 static void
 }
 
 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
 {
 
 #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);
                printf("opt_loop(root, %d) begin\n", do_stmts);

-               opt_dump(cstate, ic);
+               opt_dump(opt_state, ic);

        }
 #endif
        do {
        }
 #endif
        do {


@@ -1684,11 +1902,11 @@ opt_loop(compiler_state_t *cstate, opt_state_t *opt_state, struct icode *ic,
                find_closure(opt_state, ic->root);
                find_ud(opt_state, ic->root);
                find_edom(opt_state, ic->root);
                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
 #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);
                        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);
                }
 #endif
        } while (!opt_state->done);


@@ -1696,30 +1914,38 @@ opt_loop(compiler_state_t *cstate, opt_state_t *opt_state, struct icode *ic,
 
 /*
  * Optimize the filter code in its dag representation.
 
 /*
  * 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_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
        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");
                printf("after intern_blocks()\n");

-               opt_dump(cstate, ic);
+               opt_dump(&opt_state, ic);

        }
 #endif
        opt_root(&ic->root);
 #ifdef BDEBUG
        }
 #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");
                printf("after opt_root()\n");

-               opt_dump(cstate, ic);
+               opt_dump(&opt_state, ic);

        }
 #endif
        opt_cleanup(&opt_state);
        }
 #endif
        opt_cleanup(&opt_state);

+       return 0;

 }
 
 static void
 }
 
 static void


@@ -1752,7 +1978,7 @@ mark_code(struct icode *ic)
 static int
 eq_slist(struct slist *x, struct slist *y)
 {
 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)
                while (x && x->s.code == NOP)
                        x = x->next;
                while (y && y->s.code == NOP)


@@ -1833,6 +2059,24 @@ opt_cleanup(opt_state_t *opt_state)
        free((void *)opt_state->blocks);
 }
 
        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'.
  */
 /*
  * Return the number of stmts in 's'.
  */


@@ -1917,7 +2161,7 @@ count_stmts(struct icode *ic, struct block *p)
  * from the total number of blocks and/or statements.
  */
 static void
  * 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;
 {
        bpf_u_int32 *p;
        int i, n, max_stmts;


@@ -1930,22 +2174,24 @@ opt_init(compiler_state_t *cstate, opt_state_t *opt_state, struct icode *ic)
        n = count_blocks(ic, ic->root);
        opt_state->blocks = (struct block **)calloc(n, sizeof(*opt_state->blocks));
        if (opt_state->blocks == NULL)
        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));
        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));
 
        /*
         * 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;
 
        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;


@@ -1953,8 +2199,9 @@ opt_init(compiler_state_t *cstate, opt_state_t *opt_state, struct icode *ic)
        /* 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));
        /* 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) {
        p = opt_state->space;
        opt_state->all_dom_sets = p;
        for (i = 0; i < n; ++i) {


@@ -1991,9 +2238,13 @@ opt_init(compiler_state_t *cstate, opt_state_t *opt_state, struct icode *ic)
         */
        opt_state->maxval = 3 * max_stmts;
        opt_state->vmap = (struct vmapinfo *)calloc(opt_state->maxval, sizeof(*opt_state->vmap));
         */
        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));
        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");
+       }

 }
 
 /*
 }
 
 /*


@@ -2002,9 +2253,12 @@ opt_init(compiler_state_t *cstate, opt_state_t *opt_state, struct icode *ic)
  * and expect it to provide meaningful information.
  */
 #ifdef BDEBUG
  * and expect it to provide meaningful information.
  */
 #ifdef BDEBUG

-int bids[1000];
+int bids[NBIDS];

 #endif
 
 #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
 /*
  * Returns true if successful.  Returns false if a branch has
  * an offset that is too large.  If so, we have marked that


@@ -2012,23 +2266,22 @@ int bids[1000];
  * properly.
  */
 static int
  * 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;
 {
        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);
 
        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);
                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);
                return (0);
 
        slen = slength(p->stmts);


@@ -2041,7 +2294,7 @@ convert_code_r(compiler_state_t *cstate, conv_state_t *conv_state,
        if (slen) {
                offset = (struct slist **)calloc(slen, sizeof(struct slist *));
                if (!offset) {
        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*/
                }
        }
                        /*NOTREACHED*/
                }
        }


@@ -2065,7 +2318,8 @@ convert_code_r(compiler_state_t *cstate, conv_state_t *conv_state,
                if (BPF_CLASS(src->s.code) != BPF_JMP || src->s.code == (BPF_JMP|BPF_JA)) {
 #if 0
                        if (src->s.jt || src->s.jf) {
                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
                                /*NOTREACHED*/
                        }
 #endif


@@ -2077,7 +2331,7 @@ convert_code_r(compiler_state_t *cstate, conv_state_t *conv_state,
            {
                u_int i;
                int jt, jf;
            {
                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,
 
 #if 0
                printf("code=%x off=%d %x %x\n", src->s.code,


@@ -2085,7 +2339,8 @@ convert_code_r(compiler_state_t *cstate, conv_state_t *conv_state,
 #endif
 
                if (!src->s.jt || !src->s.jf) {
 #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*/
                }
 
                        /*NOTREACHED*/
                }
 


@@ -2093,24 +2348,37 @@ convert_code_r(compiler_state_t *cstate, conv_state_t *conv_state,
                for (i = 0; i < slen; i++) {
                        if (offset[i] == src->s.jt) {
                                if (jt) {
                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*/
                                }
 
                                        /*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) {
                                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*/
                                }
                                        /*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) {
                                jf++;
                        }
                }
                if (!jt || !jf) {

-                       bpf_error(cstate, ljerr, "no destination found", off);
+                       free(offset);
+                       conv_error(conv_state, ljerr, "no destination found", off);

                        /*NOTREACHED*/
                }
            }
                        /*NOTREACHED*/
                }
            }


@@ -2122,7 +2390,8 @@ filled:
                free(offset);
 
 #ifdef BDEBUG
                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;
 #endif
        dst->code = (u_short)p->s.code;
        dst->k = p->s.k;


@@ -2137,13 +2406,17 @@ filled:
                        return(0);
                    }
                    /* branch if T to following jump */
                        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
                    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 */
                off = JF(p)->offset - (p->offset + slen) - 1;
                if (off >= 256) {
                    /* offset too large for branch, must add a jump */


@@ -2154,13 +2427,17 @@ filled:
                    }
                    /* branch if F to following jump */
                    /* if two jumps are inserted, F goes to second one */
                    }
                    /* 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
                    extrajmps++;
                    dst[extrajmps].code = BPF_JMP|BPF_JA;
                    dst[extrajmps].k = off - extrajmps;
                }
                else

-                   dst->jf = off;
+                   dst->jf = (u_char)off;

        }
        return (1);
 }
        }
        return (1);
 }


@@ -2185,30 +2462,41 @@ filled:
  * done with the filter program.  See the pcap man page.
  */
 struct bpf_insn *
  * 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;
 
 {
        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.
         */
        /*
         * 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);
            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);
            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);
        }
                break;
            free(fp);
        }


@@ -2216,6 +2504,22 @@ icode_to_fcode(compiler_state_t *cstate, struct icode *ic,
        return 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".
 /*
  * Make a copy of a BPF program and put it in the "fcode" member of
  * a "pcap_t".


@@ -2232,8 +2536,8 @@ install_bpf_program(pcap_t *p, struct bpf_program *fp)
        /*
         * Validate the program.
         */
        /*
         * 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);
        }
                        "BPF program is not valid");
                return (-1);
        }


@@ -2247,8 +2551,8 @@ install_bpf_program(pcap_t *p, struct bpf_program *fp)
        p->fcode.bf_len = fp->bf_len;
        p->fcode.bf_insns = (struct bpf_insn *)malloc(prog_size);
        if (p->fcode.bf_insns == NULL) {
        p->fcode.bf_len = fp->bf_len;
        p->fcode.bf_insns = (struct bpf_insn *)malloc(prog_size);
        if (p->fcode.bf_insns == NULL) {

-               pcap_snprintf(p->errbuf, sizeof(p->errbuf),
-                        "malloc: %s", pcap_strerror(errno));
+               pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
+                   errno, "malloc");

                return (-1);
        }
        memcpy(p->fcode.bf_insns, fp->bf_insns, prog_size);
                return (-1);
        }
        memcpy(p->fcode.bf_insns, fp->bf_insns, prog_size);


@@ -2325,14 +2629,16 @@ dot_dump_edge(struct icode *ic, struct block *block, FILE *out)
  *  After install graphviz on http://www.graphviz.org/, save it as bpf.dot
  *  and run `dot -Tpng -O bpf.dot' to draw the graph.
  */
  *  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);
 {
        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, "digraph BPF {\n");
        unMarkAll(ic);


@@ -2342,30 +2648,39 @@ dot_dump(compiler_state_t *cstate, struct icode *ic)
        fprintf(out, "}\n");
 
        free((char *)f.bf_insns);
        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);
 {
        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);
        bpf_dump(&f, 1);
        putchar('\n');
        free((char *)f.bf_insns);

+       return 0;

 }
 
 static void
 }
 
 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
        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
 }
 #endif