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Use nd_ types, add EXTRACT_, fix a bounds check.
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@guyharris
guyharris committed Dec 30, 2017
1 parent 0d52da1 commit 85078ee
Showing 1 changed file with 45 additions and 40 deletions.
85 changes: 45 additions & 40 deletions print-bootp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -56,22 +56,22 @@ static const char tstr[] = " [|bootp]";
*/

struct bootp {
uint8_t bp_op; /* packet opcode type */
uint8_t bp_htype; /* hardware addr type */
uint8_t bp_hlen; /* hardware addr length */
uint8_t bp_hops; /* gateway hops */
uint32_t bp_xid; /* transaction ID */
uint16_t bp_secs; /* seconds since boot began */
uint16_t bp_flags; /* flags - see bootp_flag_values[]
nd_uint8_t bp_op; /* packet opcode type */
nd_uint8_t bp_htype; /* hardware addr type */
nd_uint8_t bp_hlen; /* hardware addr length */
nd_uint8_t bp_hops; /* gateway hops */
nd_uint32_t bp_xid; /* transaction ID */
nd_uint16_t bp_secs; /* seconds since boot began */
nd_uint16_t bp_flags; /* flags - see bootp_flag_values[]
in print-bootp.c */
struct in_addr bp_ciaddr; /* client IP address */
struct in_addr bp_yiaddr; /* 'your' IP address */
struct in_addr bp_siaddr; /* server IP address */
struct in_addr bp_giaddr; /* gateway IP address */
uint8_t bp_chaddr[16]; /* client hardware address */
uint8_t bp_sname[64]; /* server host name */
uint8_t bp_file[128]; /* boot file name */
uint8_t bp_vend[64]; /* vendor-specific area */
nd_byte bp_chaddr[16]; /* client hardware address */
nd_byte bp_sname[64]; /* server host name */
nd_byte bp_file[128]; /* boot file name */
nd_byte bp_vend[64]; /* vendor-specific area */
} UNALIGNED;

#define BOOTPREPLY 2
Expand Down Expand Up @@ -239,14 +239,14 @@ struct bootp {
*/

struct cmu_vend {
uint8_t v_magic[4]; /* magic number */
uint32_t v_flags; /* flags/opcodes, etc. */
nd_byte v_magic[4]; /* magic number */
nd_uint32_t v_flags; /* flags/opcodes, etc. */
struct in_addr v_smask; /* Subnet mask */
struct in_addr v_dgate; /* Default gateway */
struct in_addr v_dns1, v_dns2; /* Domain name servers */
struct in_addr v_ins1, v_ins2; /* IEN-116 name servers */
struct in_addr v_ts1, v_ts2; /* Time servers */
uint8_t v_unused[24]; /* currently unused */
nd_byte v_unused[24]; /* currently unused */
} UNALIGNED;


Expand Down Expand Up @@ -286,17 +286,20 @@ bootp_print(netdissect_options *ndo,
const struct bootp *bp;
static const u_char vm_cmu[4] = VM_CMU;
static const u_char vm_rfc1048[4] = VM_RFC1048;
uint8_t bp_op, bp_htype, bp_hlen;

bp = (const struct bootp *)cp;
ND_TCHECK(bp->bp_op);

bp_op = EXTRACT_U_1(bp->bp_op);
ND_PRINT((ndo, "BOOTP/DHCP, %s",
tok2str(bootp_op_values, "unknown (0x%02x)", bp->bp_op)));
tok2str(bootp_op_values, "unknown (0x%02x)", bp_op)));

ND_TCHECK(bp->bp_hlen);
if (bp->bp_htype == 1 && bp->bp_hlen == 6 && bp->bp_op == BOOTPREQUEST) {
bp_htype = EXTRACT_U_1(bp->bp_htype);
bp_hlen = EXTRACT_U_1(bp->bp_hlen);
if (bp_htype == 1 && bp_hlen == 6 && bp_op == BOOTPREQUEST) {
ND_TCHECK_LEN(bp->bp_chaddr, 6);
ND_PRINT((ndo, " from %s", etheraddr_string(ndo, bp->bp_chaddr)));
ND_PRINT((ndo, " from %s", etheraddr_string(ndo, bp->bp_chaddr));
}

ND_PRINT((ndo, ", length %u", length));
Expand All @@ -307,49 +310,49 @@ bootp_print(netdissect_options *ndo,
ND_TCHECK(bp->bp_secs);

/* The usual hardware address type is 1 (10Mb Ethernet) */
if (bp->bp_htype != 1)
ND_PRINT((ndo, ", htype %d", bp->bp_htype));
if (bp_htype != 1)
ND_PRINT((ndo, ", htype %d", bp_htype));

/* The usual length for 10Mb Ethernet address is 6 bytes */
if (bp->bp_htype != 1 || bp->bp_hlen != 6)
ND_PRINT((ndo, ", hlen %d", bp->bp_hlen));
if (bp_htype != 1 || bp_hlen != 6)
ND_PRINT((ndo, ", hlen %d", bp_hlen));

/* Only print interesting fields */
if (bp->bp_hops)
ND_PRINT((ndo, ", hops %d", bp->bp_hops));
if (EXTRACT_BE_U_4(&bp->bp_xid))
ND_PRINT((ndo, ", xid 0x%x", EXTRACT_BE_U_4(&bp->bp_xid)));
if (EXTRACT_BE_U_2(&bp->bp_secs))
ND_PRINT((ndo, ", secs %d", EXTRACT_BE_U_2(&bp->bp_secs)));
if (EXTRACT_U_1(bp->bp_hops))
ND_PRINT((ndo, ", hops %d", EXTRACT_U_1(bp->bp_hops))));
if (EXTRACT_BE_U_4(bp->bp_xid))
ND_PRINT((ndo, ", xid 0x%x", EXTRACT_BE_U_4(bp->bp_xid)));
if (EXTRACT_BE_U_2(bp->bp_secs))
ND_PRINT((ndo, ", secs %d", EXTRACT_BE_U_2(bp->bp_secs)));

ND_TCHECK(bp->bp_flags);
ND_PRINT((ndo, ", Flags [%s]",
bittok2str(bootp_flag_values, "none", EXTRACT_BE_U_2(&bp->bp_flags))));
bittok2str(bootp_flag_values, "none", EXTRACT_BE_U_2(bp->bp_flags))));
if (ndo->ndo_vflag > 1)
ND_PRINT((ndo, " (0x%04x)", EXTRACT_BE_U_2(&bp->bp_flags)));
ND_PRINT((ndo, " (0x%04x)", EXTRACT_BE_U_2(bp->bp_flags)));

/* Client's ip address */
ND_TCHECK(bp->bp_ciaddr);
if (EXTRACT_BE_U_4(&bp->bp_ciaddr.s_addr))
if (EXTRACT_IPV4_TO_HOST_ORDER(&bp->bp_ciaddr.s_addr))
ND_PRINT((ndo, "\n\t Client-IP %s", ipaddr_string(ndo, &bp->bp_ciaddr)));

/* 'your' ip address (bootp client) */
ND_TCHECK(bp->bp_yiaddr);
if (EXTRACT_BE_U_4(&bp->bp_yiaddr.s_addr))
if (EXTRACT_IPV4_TO_HOST_ORDER(&bp->bp_yiaddr.s_addr))
ND_PRINT((ndo, "\n\t Your-IP %s", ipaddr_string(ndo, &bp->bp_yiaddr)));

/* Server's ip address */
ND_TCHECK(bp->bp_siaddr);
if (EXTRACT_BE_U_4(&bp->bp_siaddr.s_addr))
if (EXTRACT_IPV4_TO_HOST_ORDER(&bp->bp_siaddr.s_addr))
ND_PRINT((ndo, "\n\t Server-IP %s", ipaddr_string(ndo, &bp->bp_siaddr)));

/* Gateway's ip address */
ND_TCHECK(bp->bp_giaddr);
if (EXTRACT_BE_U_4(&bp->bp_giaddr.s_addr))
if (EXTRACT_IPV4_TO_HOST_ORDER(&bp->bp_giaddr.s_addr))
ND_PRINT((ndo, "\n\t Gateway-IP %s", ipaddr_string(ndo, &bp->bp_giaddr)));

/* Client's Ethernet address */
if (bp->bp_htype == 1 && bp->bp_hlen == 6) {
if (bp_htype == 1 && bp_hlen == 6) {
ND_TCHECK_LEN(bp->bp_chaddr, 6);
ND_PRINT((ndo, "\n\t Client-Ethernet-Address %s", etheraddr_string(ndo, bp->bp_chaddr)));
}
Expand Down Expand Up @@ -378,7 +381,7 @@ bootp_print(netdissect_options *ndo,
}

/* Decode the vendor buffer */
ND_TCHECK(bp->bp_vend[0]);
ND_TCHECK_LEN(bp->bp_vend, 4);
if (memcmp((const char *)bp->bp_vend, vm_rfc1048,
sizeof(uint32_t)) == 0)
rfc1048_print(ndo, bp->bp_vend);
Expand All @@ -388,7 +391,7 @@ bootp_print(netdissect_options *ndo,
else {
uint32_t ul;

ul = EXTRACT_BE_U_4(&bp->bp_vend);
ul = EXTRACT_BE_U_4(bp->bp_vend);
if (ul != 0)
ND_PRINT((ndo, "\n\t Vendor-#0x%x", ul));
}
Expand Down Expand Up @@ -1063,6 +1066,7 @@ cmu_print(netdissect_options *ndo,
const u_char *bp)
{
const struct cmu_vend *cmu;
uint8_t v_flags;

#define PRINTCMUADDR(m, s) { ND_TCHECK(cmu->m); \
if (cmu->m.s_addr != 0) \
Expand All @@ -1073,10 +1077,11 @@ cmu_print(netdissect_options *ndo,

/* Only print if there are unknown bits */
ND_TCHECK(cmu->v_flags);
if ((cmu->v_flags & ~(VF_SMASK)) != 0)
ND_PRINT((ndo, " F:0x%x", cmu->v_flags));
v_flags = EXTRACT_U_1(cmu->v_flags);
if ((v_flags & ~(VF_SMASK)) != 0)
ND_PRINT((ndo, " F:0x%x", v_flags));
PRINTCMUADDR(v_dgate, "DG");
PRINTCMUADDR(v_smask, cmu->v_flags & VF_SMASK ? "SM" : "SM*");
PRINTCMUADDR(v_smask, v_flags & VF_SMASK ? "SM" : "SM*");
PRINTCMUADDR(v_dns1, "NS1");
PRINTCMUADDR(v_dns2, "NS2");
PRINTCMUADDR(v_ins1, "IEN1");
Expand Down

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