xref: /freebsd/contrib/tcpdump/print-ppi.c (revision ee67461e56828dd1f8de165947ba83f6d9148a87)
1 /*
2  * Oracle
3  */
4 
5 /* \summary: Per-Packet Information (DLT_PPI) printer */
6 
7 /* Specification:
8  * Per-Packet Information Header Specification - Version 1.0.7
9  * https://web.archive.org/web/20160328114748/http://www.cacetech.com/documents/PPI%20Header%20format%201.0.7.pdf
10  */
11 
12 #ifdef HAVE_CONFIG_H
13 #include <config.h>
14 #endif
15 
16 #include "netdissect-stdinc.h"
17 
18 #include "netdissect.h"
19 #include "extract.h"
20 
21 
22 typedef struct ppi_header {
23 	nd_uint8_t	ppi_ver;	/* Version.  Currently 0 */
24 	nd_uint8_t	ppi_flags;	/* Flags. */
25 	nd_uint16_t	ppi_len;	/* Length of entire message, including
26 					 * this header and TLV payload. */
27 	nd_uint32_t	ppi_dlt;	/* Data Link Type of the captured
28 					 * packet data. */
29 } ppi_header_t;
30 
31 #define	PPI_HDRLEN	8
32 
33 #ifdef DLT_PPI
34 
35 static void
36 ppi_header_print(netdissect_options *ndo, const u_char *bp, u_int length)
37 {
38 	const ppi_header_t *hdr;
39 	uint16_t len;
40 	uint32_t dlt;
41 	const char *dltname;
42 
43 	hdr = (const ppi_header_t *)bp;
44 
45 	len = GET_LE_U_2(hdr->ppi_len);
46 	dlt = GET_LE_U_4(hdr->ppi_dlt);
47 	dltname = pcap_datalink_val_to_name(dlt);
48 
49 	if (!ndo->ndo_qflag) {
50 		ND_PRINT("V.%u DLT %s (%u) len %u", GET_U_1(hdr->ppi_ver),
51 			  (dltname != NULL ? dltname : "UNKNOWN"), dlt,
52                           len);
53         } else {
54 		ND_PRINT("%s", (dltname != NULL ? dltname : "UNKNOWN"));
55         }
56 
57 	ND_PRINT(", length %u: ", length);
58 }
59 
60 /*
61  * This is the top level routine of the printer.  'p' points
62  * to the ether header of the packet, 'h->ts' is the timestamp,
63  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
64  * is the number of bytes actually captured.
65  */
66 void
67 ppi_if_print(netdissect_options *ndo,
68 	     const struct pcap_pkthdr *h, const u_char *p)
69 {
70 	if_printer printer;
71 	const ppi_header_t *hdr;
72 	u_int caplen = h->caplen;
73 	u_int length = h->len;
74 	uint16_t len;
75 	uint32_t dlt;
76 	uint32_t hdrlen;
77 	struct pcap_pkthdr nhdr;
78 
79 	ndo->ndo_protocol = "ppi";
80 	if (caplen < sizeof(ppi_header_t)) {
81 		nd_print_trunc(ndo);
82 		ndo->ndo_ll_hdr_len += caplen;
83 		return;
84 	}
85 
86 	hdr = (const ppi_header_t *)p;
87 	len = GET_LE_U_2(hdr->ppi_len);
88 	if (len < sizeof(ppi_header_t) || len > 65532) {
89 		/* It MUST be between 8 and 65,532 inclusive (spec 3.1.3) */
90 		ND_PRINT(" [length %u < %zu or > 65532]", len,
91 			 sizeof(ppi_header_t));
92 		nd_print_invalid(ndo);
93 		ndo->ndo_ll_hdr_len += caplen;
94 		return;
95 	}
96 	if (caplen < len) {
97 		/*
98 		 * If we don't have the entire PPI header, don't
99 		 * bother.
100 		 */
101 		nd_print_trunc(ndo);
102 		ndo->ndo_ll_hdr_len += caplen;
103 		return;
104 	}
105 	dlt = GET_LE_U_4(hdr->ppi_dlt);
106 
107 	if (ndo->ndo_eflag)
108 		ppi_header_print(ndo, p, length);
109 
110 	length -= len;
111 	caplen -= len;
112 	p += len;
113 
114 	printer = lookup_printer(dlt);
115 	if (printer != NULL) {
116 		nhdr = *h;
117 		nhdr.caplen = caplen;
118 		nhdr.len = length;
119 		printer(ndo, &nhdr, p);
120 		hdrlen = ndo->ndo_ll_hdr_len;
121 	} else {
122 		if (!ndo->ndo_eflag)
123 			ppi_header_print(ndo, (const u_char *)hdr, length + len);
124 
125 		if (!ndo->ndo_suppress_default_print)
126 			ND_DEFAULTPRINT(p, caplen);
127 		hdrlen = 0;
128 	}
129 	ndo->ndo_ll_hdr_len += len + hdrlen;
130 }
131 #endif /* DLT_PPI */
132