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Don't directly fetch multi-byte integers from packets.
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Use the EXTRACT_ macros to extract multi-byte integral values from
packets, rather than just dereferencing pointers into the packet; there
is no guarantee that the packet data will be aligned on the right
boundary, and there is no guarantee that, if they're not, a direct
access will work correctly.
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@guyharris
guyharris committed Feb 21, 2010
1 parent b00042a commit e8b5237
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Showing 15 changed files with 61 additions and 55 deletions.
12 changes: 8 additions & 4 deletions print-ap1394.c
View file
Expand Up @@ -33,6 +33,7 @@ static const char rcsid[] _U_ =
#include <pcap.h>

#include "interface.h"
#include "extract.h"
#include "addrtoname.h"
#include "ethertype.h"

Expand All @@ -57,18 +58,21 @@ static inline void
ap1394_hdr_print(register const u_char *bp, u_int length)
{
register const struct firewire_header *fp;
u_int16_t firewire_type;

fp = (const struct firewire_header *)bp;

(void)printf("%s > %s",
linkaddr_string(fp->firewire_dhost, LINKADDR_IEEE1394, FIREWIRE_EUI64_LEN),
linkaddr_string(fp->firewire_shost, LINKADDR_IEEE1394, FIREWIRE_EUI64_LEN));

firewire_type = EXTRACT_16BITS(&fp->firewire_type);
if (!qflag) {
(void)printf(", ethertype %s (0x%04x)",
tok2str(ethertype_values,"Unknown", ntohs(fp->firewire_type)),
ntohs(fp->firewire_type));
tok2str(ethertype_values,"Unknown", firewire_type),
firewire_type);
} else {
(void)printf(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", ntohs(fp->firewire_type)));
(void)printf(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", firewire_type));
}

(void)printf(", length %u: ", length);
Expand Down Expand Up @@ -102,7 +106,7 @@ ap1394_if_print(const struct pcap_pkthdr *h, const u_char *p)
fp = (struct firewire_header *)p;
p += FIREWIRE_HDRLEN;

ether_type = ntohs(fp->firewire_type);
ether_type = EXTRACT_16BITS(&fp->firewire_type);

extracted_ether_type = 0;
if (ether_encap_print(ether_type, p, length, caplen,
Expand Down
5 changes: 3 additions & 2 deletions print-arcnet.c
View file
Expand Up @@ -35,6 +35,7 @@ static const char rcsid[] _U_ =
#include <pcap.h>

#include "interface.h"
#include "extract.h"
#include "arcnet.h"

static int arcnet_encap_print(u_char arctype, const u_char *p,
Expand Down Expand Up @@ -151,11 +152,11 @@ arcnet_if_print(const struct pcap_pkthdr *h, const u_char *p)
return (caplen);
}
flag = ap->arc_flag2;
seqid = ntohs(ap->arc_seqid2);
seqid = EXTRACT_16BITS(&ap->arc_seqid2);
archdrlen = ARC_HDRNEWLEN_EXC;
} else {
flag = ap->arc_flag;
seqid = ntohs(ap->arc_seqid);
seqid = EXTRACT_16BITS(&ap->arc_seqid);
archdrlen = ARC_HDRNEWLEN;
}
}
Expand Down
3 changes: 2 additions & 1 deletion print-bt.c
View file
Expand Up @@ -33,6 +33,7 @@ static const char rcsid[] _U_ =
#include <string.h>

#include "interface.h"
#include "extract.h"
#include "addrtoname.h"

#if defined(DLT_BLUETOOTH_HCI_H4_WITH_PHDR) && defined(HAVE_PCAP_BLUETOOTH_H)
Expand Down Expand Up @@ -60,7 +61,7 @@ bt_if_print(const struct pcap_pkthdr *h, const u_char *p)
length -= BT_HDRLEN;
p += BT_HDRLEN;
if (eflag)
(void)printf("hci length %d, direction %s, ", length, (ntohl(hdr->direction)&0x1)?"in":"out");
(void)printf("hci length %d, direction %s, ", length, (EXTRACT_32BITS(&hdr->direction)&0x1)?"in":"out");

if (!suppress_default_print)
default_print(p, caplen);
Expand Down
26 changes: 8 additions & 18 deletions print-dccp.c
View file
Expand Up @@ -394,9 +394,6 @@ void dccp_print(const u_char *bp, const u_char *data2, u_int len)
static int dccp_print_option(const u_char *option)
{
u_int8_t optlen, i;
u_int32_t *ts;
u_int16_t *var16;
u_int32_t *var32;

TCHECK(*option);

Expand Down Expand Up @@ -470,22 +467,17 @@ static int dccp_print_option(const u_char *option)
for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
break;
case 41:
ts = (u_int32_t *)(option + 2);
printf("timestamp %u", (u_int32_t)ntohl(*ts));
printf("timestamp %u", EXTRACT_32BITS(option + 2));
break;
case 42:
ts = (u_int32_t *)(option + 2);
printf("timestamp_echo %u", (u_int32_t)ntohl(*ts));
printf("timestamp_echo %u", EXTRACT_32BITS(option + 2));
break;
case 43:
printf("elapsed_time ");
if (optlen == 6){
ts = (u_int32_t *)(option + 2);
printf("%u", (u_int32_t)ntohl(*ts));
} else {
var16 = (u_int16_t *)(option + 2);
printf("%u", ntohs(*var16));
}
if (optlen == 6)
printf("%u", EXTRACT_32BITS(option + 2));
else
printf("%u", EXTRACT_16BITS(option + 2));
break;
case 44:
printf("data_checksum ");
Expand All @@ -496,12 +488,10 @@ static int dccp_print_option(const u_char *option)
printf("CCID option %d",*option);
switch (optlen) {
case 4:
var16 = (u_int16_t *)(option + 2);
printf(" %u",ntohs(*var16));
printf(" %u", EXTRACT_16BITS(option + 2));
break;
case 6:
var32 = (u_int32_t *)(option + 2);
printf(" %u",(u_int32_t)ntohl(*var32));
printf(" %u", EXTRACT_32BITS(option + 2));
break;
default:
break;
Expand Down
3 changes: 2 additions & 1 deletion print-enc.c
View file
Expand Up @@ -35,6 +35,7 @@ static const char rcsid[] _U_ =
#include <pcap.h>

#include "interface.h"
#include "extract.h"
#include "addrtoname.h"

#include "enc.h"
Expand Down Expand Up @@ -67,7 +68,7 @@ enc_if_print(const struct pcap_pkthdr *h, register const u_char *p)
ENC_PRINT_TYPE(flags, M_AUTH, "authentic");
ENC_PRINT_TYPE(flags, M_CONF, "confidential");
/* ENC_PRINT_TYPE(flags, M_TUNNEL, "tunnel"); */
printf("SPI 0x%08x: ", (u_int32_t)ntohl(hdr->spi));
printf("SPI 0x%08x: ", EXTRACT_32BITS(&hdr->spi));

length -= ENC_HDRLEN;
caplen -= ENC_HDRLEN;
Expand Down
4 changes: 2 additions & 2 deletions print-esp.c
View file
Expand Up @@ -600,7 +600,7 @@ esp_print(netdissect_options *ndo,
/* see if we can find the SA, and if so, decode it */
for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&sa->daddr;
if (sa->spi == ntohl(esp->esp_spi) &&
if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) &&
sin6->sin6_family == AF_INET6 &&
memcmp(&sin6->sin6_addr, &ip6->ip6_dst,
sizeof(struct in6_addr)) == 0) {
Expand All @@ -618,7 +618,7 @@ esp_print(netdissect_options *ndo,
/* see if we can find the SA, and if so, decode it */
for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
struct sockaddr_in *sin = (struct sockaddr_in *)&sa->daddr;
if (sa->spi == ntohl(esp->esp_spi) &&
if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) &&
sin->sin_family == AF_INET &&
sin->sin_addr.s_addr == ip->ip_dst.s_addr) {
break;
Expand Down
33 changes: 20 additions & 13 deletions print-ether.c
View file
Expand Up @@ -33,6 +33,7 @@ static const char rcsid[] _U_ =
#include <pcap.h>

#include "interface.h"
#include "extract.h"
#include "addrtoname.h"
#include "ethertype.h"

Expand Down Expand Up @@ -86,24 +87,27 @@ static inline void
ether_hdr_print(register const u_char *bp, u_int length)
{
register const struct ether_header *ep;
u_int16_t ether_type;

ep = (const struct ether_header *)bp;

(void)printf("%s > %s",
etheraddr_string(ESRC(ep)),
etheraddr_string(EDST(ep)));

ether_type = EXTRACT_16BITS(&ep->ether_type);
if (!qflag) {
if (ntohs(ep->ether_type) <= ETHERMTU)
if (ether_type <= ETHERMTU)
(void)printf(", 802.3");
else
(void)printf(", ethertype %s (0x%04x)",
tok2str(ethertype_values,"Unknown", ntohs(ep->ether_type)),
ntohs(ep->ether_type));
tok2str(ethertype_values,"Unknown", ether_type),
ether_type);
} else {
if (ntohs(ep->ether_type) <= ETHERMTU)
if (ether_type <= ETHERMTU)
(void)printf(", 802.3");
else
(void)printf(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", ntohs(ep->ether_type)));
(void)printf(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", ether_type));
}

(void)printf(", length %u: ", length);
Expand All @@ -129,7 +133,7 @@ ether_print(const u_char *p, u_int length, u_int caplen)
ep = (struct ether_header *)p;
p += ETHER_HDRLEN;

ether_type = ntohs(ep->ether_type);
ether_type = EXTRACT_16BITS(&ep->ether_type);

/*
* Is it (gag) an 802.3 encapsulation?
Expand Down Expand Up @@ -226,13 +230,16 @@ ether_encap_print(u_short ether_type, const u_char *p,
return (1);

case ETHERTYPE_8021Q:
if (eflag)
printf("vlan %u, p %u%s, ",
ntohs(*(u_int16_t *)p) & 0xfff,
ntohs(*(u_int16_t *)p) >> 13,
(ntohs(*(u_int16_t *)p) & 0x1000) ? ", CFI" : "");
if (eflag) {
u_int16_t tag = EXTRACT_16BITS(p);

printf("vlan %u, p %u%s, ",
tag & 0xfff,
tag >> 13,
(tag & 0x1000) ? ", CFI" : "");
}

ether_type = ntohs(*(u_int16_t *)(p + 2));
ether_type = EXTRACT_16BITS(p + 2);
p += 4;
length -= 4;
caplen -= 4;
Expand All @@ -259,7 +266,7 @@ ether_encap_print(u_short ether_type, const u_char *p,
return (1);

case ETHERTYPE_JUMBO:
ether_type = ntohs(*(u_int16_t *)(p));
ether_type = EXTRACT_16BITS(p);
p += 2;
length -= 2;
caplen -= 2;
Expand Down
6 changes: 3 additions & 3 deletions print-icmp6.c
View file
Expand Up @@ -853,7 +853,7 @@ mldv2_report_print(const u_char *bp, u_int len)
}

TCHECK(icp->icmp6_data16[1]);
ngroups = ntohs(icp->icmp6_data16[1]);
ngroups = EXTRACT_16BITS(&icp->icmp6_data16[1]);
printf(", %d group record(s)", ngroups);
if (vflag > 0) {
/* Print the group records */
Expand Down Expand Up @@ -912,7 +912,7 @@ mldv2_query_print(const u_char *bp, u_int len)
return;
}
TCHECK(icp->icmp6_data16[0]);
mrc = ntohs(icp->icmp6_data16[0]);
mrc = EXTRACT_16BITS(&icp->icmp6_data16[0]);
if (mrc < 32768) {
mrt = mrc;
} else {
Expand Down Expand Up @@ -941,7 +941,7 @@ mldv2_query_print(const u_char *bp, u_int len)
}

TCHECK2(bp[26], 2);
nsrcs = ntohs(*(u_short *)&bp[26]);
nsrcs = EXTRACT_16BITS(&bp[26]);
if (nsrcs > 0) {
if (len < 28 + nsrcs * sizeof(struct in6_addr))
printf(" [invalid number of sources]");
Expand Down
2 changes: 1 addition & 1 deletion print-ospf.c
View file
Expand Up @@ -982,7 +982,7 @@ ospf_decode_v2(register const struct ospfhdr *op,
bittok2str(ospf_dd_flag_values,"none",op->ospf_db.db_flags));
TCHECK(op->ospf_db.db_ifmtu);
if (op->ospf_db.db_ifmtu) {
printf(", MTU: %u", ntohs(op->ospf_db.db_ifmtu));
printf(", MTU: %u", EXTRACT_16BITS(&op->ospf_db.db_ifmtu));
}
TCHECK(op->ospf_db.db_seq);
printf(", Sequence: 0x%08x", EXTRACT_32BITS(&op->ospf_db.db_seq));
Expand Down
4 changes: 2 additions & 2 deletions print-pflog.c
View file
Expand Up @@ -94,8 +94,8 @@ pflog_print(const struct pfloghdr *hdr)
{
u_int32_t rulenr, subrulenr;

rulenr = ntohl(hdr->rulenr);
subrulenr = ntohl(hdr->subrulenr);
rulenr = EXTRACT_32BITS(&hdr->rulenr);
subrulenr = EXTRACT_32BITS(&hdr->subrulenr);
if (subrulenr == (u_int32_t)-1)
printf("rule %u/", rulenr);
else
Expand Down
4 changes: 2 additions & 2 deletions print-ppp.c
View file
Expand Up @@ -1629,7 +1629,7 @@ ppp_bsdos_if_print(const struct pcap_pkthdr *h _U_, register const u_char *p _U_
hdrlength += 1;
} else {
/* Un-compressed protocol field */
ptype = ntohs(*(u_int16_t *)p);
ptype = EXTRACT_16BITS(p);
if (eflag)
printf("%04x ", ptype);
p += 2;
Expand All @@ -1649,7 +1649,7 @@ ppp_bsdos_if_print(const struct pcap_pkthdr *h _U_, register const u_char *p _U_
&& ph->phdr_ctl == PPP_CONTROL) {
if (eflag)
printf("%02x %02x ", q[0], q[1]);
ptype = ntohs(ph->phdr_type);
ptype = EXTRACT_16BITS(&ph->phdr_type);
if (eflag && (ptype == PPP_VJC || ptype == PPP_VJNC)) {
printf("%s ", tok2str(ppptype2str,
"proto-#%d", ptype));
Expand Down
2 changes: 1 addition & 1 deletion print-sll.c
View file
Expand Up @@ -142,7 +142,7 @@ sll_if_print(const struct pcap_pkthdr *h, const u_char *p)
caplen -= SLL_HDR_LEN;
p += SLL_HDR_LEN;

ether_type = ntohs(sllp->sll_protocol);
ether_type = EXTRACT_16BITS(&sllp->sll_protocol);

/*
* Is it (gag) an 802.3 encapsulation, or some non-Ethernet
Expand Down
5 changes: 3 additions & 2 deletions print-symantec.c
View file
Expand Up @@ -33,6 +33,7 @@ static const char rcsid[] _U_ =
#include <pcap.h>

#include "interface.h"
#include "extract.h"
#include "addrtoname.h"
#include "ethertype.h"

Expand All @@ -52,7 +53,7 @@ symantec_hdr_print(register const u_char *bp, u_int length)

sp = (const struct symantec_header *)bp;

etype = ntohs(sp->ether_type);
etype = EXTRACT_16BITS(&sp->ether_type);
if (!qflag) {
if (etype <= ETHERMTU)
(void)printf("invalid ethertype %u", etype);
Expand Down Expand Up @@ -98,7 +99,7 @@ symantec_if_print(const struct pcap_pkthdr *h, const u_char *p)
sp = (struct symantec_header *)p;
p += sizeof (struct symantec_header);

ether_type = ntohs(sp->ether_type);
ether_type = EXTRACT_16BITS(&sp->ether_type);

if (ether_type <= ETHERMTU) {
/* ether_type not known, print raw packet */
Expand Down
2 changes: 1 addition & 1 deletion print-tcp.c
View file
Expand Up @@ -759,7 +759,7 @@ tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
ip6 = (struct ip6_hdr *)ip;
MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
len32 = htonl(ntohs(ip6->ip6_plen));
len32 = htonl(EXTRACT_16BITS(&ip6->ip6_plen));
MD5_Update(&ctx, (char *)&len32, sizeof(len32));
nxt = 0;
MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
Expand Down
5 changes: 3 additions & 2 deletions print-token.c
View file
Expand Up @@ -39,6 +39,7 @@ static const char rcsid[] _U_ =
#include <string.h>

#include "interface.h"
#include "extract.h"
#include "addrtoname.h"
#include "ethertype.h"

Expand Down Expand Up @@ -135,10 +136,10 @@ token_print(const u_char *p, u_int length, u_int caplen)
printf(" [%d:%d]", RING_NUMBER(trp, seg),
BRIDGE_NUMBER(trp, seg));
} else {
printf("rt = %x", ntohs(trp->token_rcf));
printf("rt = %x", EXTRACT_16BITS(&trp->token_rcf));

for (seg = 0; seg < SEGMENT_COUNT(trp); seg++)
printf(":%x", ntohs(trp->token_rseg[seg]));
printf(":%x", EXTRACT_16BITS(&trp->token_rseg[seg]));
}
printf(" (%s) ", largest_frame[LARGEST_FRAME(trp)]);
} else {
Expand Down

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