Change the way we dissect some structures entries.

This should fix Coverity CIDs 1427590 and 1427592.

diff --git a/print-lwres.c b/print-lwres.c
index 532d5d5c17c4fea427dbbe8c4141faea5cae937c..e9d3e83fc6605807b01b5943bcd6f08cf01c5be7 100644 (file)
--- a/print-lwres.c
+++ b/print-lwres.c
@@ -97,6 +97,7 @@ struct lwres_addr {
        lwres_uint16_t                  length;
        /* address folows */
 };
+#define LWRES_ADDR_LEN                 6
 
 typedef struct {
        /* public */
@@ -105,6 +106,7 @@ typedef struct {
        lwres_uint16_t                  namelen;
        /* name follows */
 } lwres_gabnrequest_t;
+#define LWRES_GABNREQUEST_LEN          10
 
 typedef struct {
        /* public */
@@ -116,6 +118,7 @@ typedef struct {
        /* addrs follows */
        /* realname follows */
 } lwres_gabnresponse_t;
+#define LWRES_GABNRESPONSE_LEN         10
 
 /*
  * get name by address
@@ -124,9 +127,9 @@ typedef struct {
 typedef struct {
        /* public */
        lwres_uint32_t                  flags;
-       lwres_addr_t                    addr;
-       /* addr body follows */
+       /* addr follows */
 } lwres_gnbarequest_t;
+#define LWRES_GNBAREQUEST_LEN          4
 
 typedef struct {
        /* public */
@@ -136,6 +139,7 @@ typedef struct {
        /* aliases follows */
        /* realname follows */
 } lwres_gnbaresponse_t;
+#define LWRES_GNBARESPONSE_LEN         8
 
 /*
  * get rdata by name
@@ -150,6 +154,7 @@ typedef struct {
        lwres_uint16_t                  namelen;
        /* name follows */
 } lwres_grbnrequest_t;
+#define LWRES_GRBNREQUEST_LEN          10
 
 typedef struct {
        /* public */
@@ -163,6 +168,7 @@ typedef struct {
        /* rdata here (len + name) */
        /* signatures here (len + name) */
 } lwres_grbnresponse_t;
+#define LWRES_GRBNRESPONSE_LEN         16
 
 #define LWRDATA_VALIDATED      0x00000001
 
@@ -186,14 +192,14 @@ extern const struct tok ns_class2str[];
 
 static int
 lwres_printname(netdissect_options *ndo,
-                size_t l, const char *p0)
+                size_t l, const u_char *p0)
 {
-       const char *p;
+       const u_char *p;
        size_t i;
 
        p = p0;
        /* + 1 for terminating \0 */
-       if (p + l + 1 > (const char *)ndo->ndo_snapend)
+       if (p + l + 1 > ndo->ndo_snapend)
                goto trunc;
 
        ND_PRINT(" ");
@@ -209,12 +215,12 @@ lwres_printname(netdissect_options *ndo,
 
 static int
 lwres_printnamelen(netdissect_options *ndo,
-                   const char *p)
+                   const u_char *p)
 {
        uint16_t l;
        int advance;
 
-       if (p + 2 > (const char *)ndo->ndo_snapend)
+       if (p + 2 > ndo->ndo_snapend)
                goto trunc;
        l = EXTRACT_BE_U_2(p);
        advance = lwres_printname(ndo, l, p + 2);
@@ -228,17 +234,17 @@ lwres_printnamelen(netdissect_options *ndo,
 
 static int
 lwres_printbinlen(netdissect_options *ndo,
-                  const char *p0)
+                  const u_char *p0)
 {
-       const char *p;
+       const u_char *p;
        uint16_t l;
        int i;
 
        p = p0;
-       if (p + 2 > (const char *)ndo->ndo_snapend)
+       if (p + 2 > ndo->ndo_snapend)
                goto trunc;
        l = EXTRACT_BE_U_2(p);
-       if (p + 2 + l > (const char *)ndo->ndo_snapend)
+       if (p + 2 + l > ndo->ndo_snapend)
                goto trunc;
        p += 2;
        for (i = 0; i < l; i++)
@@ -251,16 +257,18 @@ lwres_printbinlen(netdissect_options *ndo,
 
 static int
 lwres_printaddr(netdissect_options *ndo,
-                const lwres_addr_t *ap)
+                const u_char *p0)
 {
+       const u_char *p;
+       const lwres_addr_t *ap;
        uint16_t l;
-       const char *p;
        int i;
 
+       p = p0;
+       ap = (const lwres_addr_t *)p;
        ND_TCHECK(ap->length);
        l = EXTRACT_BE_U_2(ap->length);
-       /* XXX ap points to packed struct */
-       p = (const char *)&ap->length + sizeof(ap->length);
+       p += LWRES_ADDR_LEN;
        ND_TCHECK_LEN(p, l);
 
        switch (EXTRACT_BE_U_4(ap->family)) {
@@ -282,7 +290,7 @@ lwres_printaddr(netdissect_options *ndo,
                        ND_PRINT("%02x", *p++);
        }
 
-       return p - (const char *)ap;
+       return p - p0;
 
   trunc:
        return -1;
@@ -292,9 +300,10 @@ void
 lwres_print(netdissect_options *ndo,
             const u_char *bp, u_int length)
 {
+       const u_char *p;
        const struct lwres_lwpacket *np;
        uint32_t v;
-       const char *s;
+       const u_char *s;
        int response;
        int advance;
        int unsupported = 0;
@@ -307,7 +316,7 @@ lwres_print(netdissect_options *ndo,
        if (ndo->ndo_vflag || v != LWRES_LWPACKETVERSION_0)
                ND_PRINT(" v%u", v);
        if (v != LWRES_LWPACKETVERSION_0) {
-               s = (const char *)np + EXTRACT_BE_U_4(np->length);
+               s = bp + EXTRACT_BE_U_4(np->length);
                goto tail;
        }
 
@@ -315,8 +324,7 @@ lwres_print(netdissect_options *ndo,
 
        /* opcode and pktflags */
        v = EXTRACT_BE_U_4(np->opcode);
-       s = tok2str(opcode, "#0x%x", v);
-       ND_PRINT(" %s%s", s, response ? "" : "?");
+       ND_PRINT(" %s%s", tok2str(opcode, "#0x%x", v), response ? "" : "?");
 
        /* pktflags */
        v = EXTRACT_BE_U_2(np->pktflags);
@@ -351,16 +359,13 @@ lwres_print(netdissect_options *ndo,
                gnba = NULL;
                grbn = NULL;
 
+               p = (const u_char *)(np + 1);
                switch (EXTRACT_BE_U_4(np->opcode)) {
                case LWRES_OPCODE_NOOP:
                        break;
                case LWRES_OPCODE_GETADDRSBYNAME:
-                       gabn = (const lwres_gabnrequest_t *)(np + 1);
+                       gabn = (const lwres_gabnrequest_t *)p;
                        ND_TCHECK(gabn->namelen);
-                       /* XXX gabn points to packed struct */
-                       s = (const char *)&gabn->namelen +
-                           sizeof(gabn->namelen);
-                       l = EXTRACT_BE_U_2(gabn->namelen);
 
                        /* BIND910: not used */
                        if (ndo->ndo_vflag > 2) {
@@ -383,14 +388,16 @@ lwres_print(netdissect_options *ndo,
                        if (v & ~(LWRES_ADDRTYPE_V4 | LWRES_ADDRTYPE_V6))
                                ND_PRINT("[0x%x]", v);
 
+                       s = p + LWRES_GABNREQUEST_LEN;
+                       l = EXTRACT_BE_U_2(gabn->namelen);
                        advance = lwres_printname(ndo, l, s);
                        if (advance < 0)
                                goto trunc;
                        s += advance;
                        break;
                case LWRES_OPCODE_GETNAMEBYADDR:
-                       gnba = (const lwres_gnbarequest_t *)(np + 1);
-                       ND_TCHECK(gnba->addr);
+                       gnba = (const lwres_gnbarequest_t *)p;
+                       ND_TCHECK(gnba->flags);
 
                        /* BIND910: not used */
                        if (ndo->ndo_vflag > 2) {
@@ -398,16 +405,15 @@ lwres_print(netdissect_options *ndo,
                                    EXTRACT_BE_U_4(gnba->flags));
                        }
 
-                       s = (const char *)&gnba->addr;
-
-                       advance = lwres_printaddr(ndo, &gnba->addr);
+                       s = p + LWRES_GNBAREQUEST_LEN;
+                       advance = lwres_printaddr(ndo, s);
                        if (advance < 0)
                                goto trunc;
                        s += advance;
                        break;
                case LWRES_OPCODE_GETRDATABYNAME:
                        /* XXX no trace, not tested */
-                       grbn = (const lwres_grbnrequest_t *)(np + 1);
+                       grbn = (const lwres_grbnrequest_t *)p;
                        ND_TCHECK(grbn->namelen);
 
                        /* BIND910: not used */
@@ -423,11 +429,8 @@ lwres_print(netdissect_options *ndo,
                                    EXTRACT_BE_U_2(grbn->rdclass)));
                        }
 
-                       /* XXX grbn points to packed struct */
-                       s = (const char *)&grbn->namelen +
-                           sizeof(grbn->namelen);
+                       s = p + LWRES_GRBNREQUEST_LEN;
                        l = EXTRACT_BE_U_2(grbn->namelen);
-
                        advance = lwres_printname(ndo, l, s);
                        if (advance < 0)
                                goto trunc;
@@ -451,16 +454,13 @@ lwres_print(netdissect_options *ndo,
                gnba = NULL;
                grbn = NULL;
 
+               p = (const u_char *)(np + 1);
                switch (EXTRACT_BE_U_4(np->opcode)) {
                case LWRES_OPCODE_NOOP:
                        break;
                case LWRES_OPCODE_GETADDRSBYNAME:
-                       gabn = (const lwres_gabnresponse_t *)(np + 1);
+                       gabn = (const lwres_gabnresponse_t *)p;
                        ND_TCHECK(gabn->realnamelen);
-                       /* XXX gabn points to packed struct */
-                       s = (const char *)&gabn->realnamelen +
-                           sizeof(gabn->realnamelen);
-                       l = EXTRACT_BE_U_2(gabn->realnamelen);
 
                        /* BIND910: not used */
                        if (ndo->ndo_vflag > 2) {
@@ -471,6 +471,8 @@ lwres_print(netdissect_options *ndo,
                        ND_PRINT(" %u/%u", EXTRACT_BE_U_2(gabn->naliases),
                                  EXTRACT_BE_U_2(gabn->naddrs));
 
+                       s = p + LWRES_GABNRESPONSE_LEN;
+                       l = EXTRACT_BE_U_2(gabn->realnamelen);
                        advance = lwres_printname(ndo, l, s);
                        if (advance < 0)
                                goto trunc;
@@ -488,19 +490,15 @@ lwres_print(netdissect_options *ndo,
                        /* addrs */
                        na = EXTRACT_BE_U_2(gabn->naddrs);
                        for (i = 0; i < na; i++) {
-                               advance = lwres_printaddr(ndo, (const lwres_addr_t *)s);
+                               advance = lwres_printaddr(ndo, s);
                                if (advance < 0)
                                        goto trunc;
                                s += advance;
                        }
                        break;
                case LWRES_OPCODE_GETNAMEBYADDR:
-                       gnba = (const lwres_gnbaresponse_t *)(np + 1);
+                       gnba = (const lwres_gnbaresponse_t *)p;
                        ND_TCHECK(gnba->realnamelen);
-                       /* XXX gnba points to packed struct */
-                       s = (const char *)&gnba->realnamelen +
-                           sizeof(gnba->realnamelen);
-                       l = EXTRACT_BE_U_2(gnba->realnamelen);
 
                        /* BIND910: not used */
                        if (ndo->ndo_vflag > 2) {
@@ -510,6 +508,8 @@ lwres_print(netdissect_options *ndo,
 
                        ND_PRINT(" %u", EXTRACT_BE_U_2(gnba->naliases));
 
+                       s = p + LWRES_GNBARESPONSE_LEN;
+                       l = EXTRACT_BE_U_2(gnba->realnamelen);
                        advance = lwres_printname(ndo, l, s);
                        if (advance < 0)
                                goto trunc;
@@ -526,7 +526,7 @@ lwres_print(netdissect_options *ndo,
                        break;
                case LWRES_OPCODE_GETRDATABYNAME:
                        /* XXX no trace, not tested */
-                       grbn = (const lwres_grbnresponse_t *)(np + 1);
+                       grbn = (const lwres_grbnresponse_t *)p;
                        ND_TCHECK(grbn->nsigs);
 
                        /* BIND910: not used */
@@ -547,9 +547,7 @@ lwres_print(netdissect_options *ndo,
                        ND_PRINT(" %u/%u", EXTRACT_BE_U_2(grbn->nrdatas),
                                  EXTRACT_BE_U_2(grbn->nsigs));
 
-                       /* XXX grbn points to packed struct */
-                       s = (const char *)&grbn->nsigs+ sizeof(grbn->nsigs);
-
+                       s = p + LWRES_GRBNRESPONSE_LEN;
                        advance = lwres_printnamelen(ndo, s);
                        if (advance < 0)
                                goto trunc;
@@ -587,7 +585,7 @@ lwres_print(netdissect_options *ndo,
                ND_PRINT(" [len: %u != %u]", EXTRACT_BE_U_4(np->length),
                          length);
        }
-       if (!unsupported && s < (const char *)np + EXTRACT_BE_U_4(np->length))
+       if (!unsupported && s < bp + EXTRACT_BE_U_4(np->length))
                ND_PRINT("[extra]");
        return;