1: /*
2: * $Id: libnet_build_cdp.c,v 1.1.1.3 2023/09/27 11:11:38 misho Exp $
3: *
4: * libnet
5: * libnet_build_cdp.c - CDP packet assembler
6: *
7: * Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>
8: * All rights reserved.
9: *
10: * Redistribution and use in source and binary forms, with or without
11: * modification, are permitted provided that the following conditions
12: * are met:
13: * 1. Redistributions of source code must retain the above copyright
14: * notice, this list of conditions and the following disclaimer.
15: * 2. Redistributions in binary form must reproduce the above copyright
16: * notice, this list of conditions and the following disclaimer in the
17: * documentation and/or other materials provided with the distribution.
18: *
19: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29: * SUCH DAMAGE.
30: *
31: */
32:
33: #include "common.h"
34:
35: libnet_ptag_t
36: libnet_build_cdp(uint8_t version, uint8_t ttl, uint16_t sum, uint16_t type,
37: uint16_t len, const uint8_t *value, const uint8_t *payload, uint32_t payload_s,
38: libnet_t *l, libnet_ptag_t ptag)
39: {
40: uint32_t n,h;
41: libnet_pblock_t *p;
42: struct libnet_cdp_hdr cdp_hdr;
43:
44: if (l == NULL)
45: {
46: return (-1);
47: }
48:
49: n = LIBNET_CDP_H + LIBNET_CDP_H + len + payload_s;
50: h = LIBNET_CDP_H + LIBNET_CDP_H + len + payload_s;
51:
52: /*
53: * Find the existing protocol block if a ptag is specified, or create
54: * a new one.
55: */
56: p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_CDP_H);
57: if (p == NULL)
58: {
59: return (-1);
60: }
61:
62: memset(&cdp_hdr, 0, sizeof(cdp_hdr));
63: cdp_hdr.cdp_version = version;
64: cdp_hdr.cdp_ttl = ttl;
65: cdp_hdr.cdp_sum = (sum ? htons(sum) : 0);
66: cdp_hdr.cdp_type = htons(type);
67: cdp_hdr.cdp_len = htons(len + 4); /* 4 bytes for len and type */
68:
69: n = libnet_pblock_append(l, p, (uint8_t *)&cdp_hdr, LIBNET_CDP_H);
70: if (n == -1)
71: {
72: goto bad;
73: }
74:
75: n = libnet_pblock_append(l, p, value, len);
76: if (n == -1)
77: {
78: /* err msg set in libnet_pblock_append() */
79: goto bad;
80: }
81:
82: /* boilerplate payload sanity check / append macro */
83: LIBNET_DO_PAYLOAD(l, p);
84:
85: if (sum == 0)
86: {
87: /*
88: * If checksum is zero, by default libnet will compute a checksum
89: * for the user. The programmer can override this by calling
90: * libnet_toggle_checksum(l, ptag, 1);
91: */
92: libnet_pblock_setflags(p, LIBNET_PBLOCK_DO_CHECKSUM);
93: }
94: return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_CDP_H));
95: bad:
96: libnet_pblock_delete(l, p);
97: return (-1);
98: }
99:
100:
101: int
102: /* Not Yet Implemented */
103: libnet_build_cdp_value(uint16_t type, uint16_t len, uint8_t *value, libnet_t *l,
104: libnet_ptag_t ptag)
105: {
106: uint32_t n;
107: libnet_pblock_t *p;
108: struct libnet_cdp_value_hdr cdp_value_hdr;
109:
110: if (l == NULL)
111: {
112: return (-1);
113: }
114:
115: /*
116: * Find the existing protocol block.
117: */
118: p = libnet_pblock_find(l, ptag);
119: if (p == NULL)
120: {
121: /* err msg set in libnet_pblock_find */
122: return (-1);
123: }
124: if (p->type != LIBNET_PBLOCK_CDP_H)
125: {
126: snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
127: "libnet_build_cdp_value: ptag references different type than expected");
128: return (-1);
129: }
130:
131: memset(&cdp_value_hdr, 0, sizeof(cdp_value_hdr));
132: cdp_value_hdr.cdp_type = htons(type);
133: cdp_value_hdr.cdp_len = htons(len + LIBNET_CDP_VALUE_H); /* 4 bytes for len and type */
134:
135: switch (type)
136: {
137: case LIBNET_CDP_DEVID:
138: break;
139: case LIBNET_CDP_ADDRESS:
140: break;
141: case LIBNET_CDP_PORTID:
142: break;
143: case LIBNET_CDP_CAPABIL:
144: break;
145: case LIBNET_CDP_VERSION:
146: break;
147: case LIBNET_CDP_PLATFORM:
148: break;
149: case LIBNET_CDP_IPPREFIX:
150: break;
151: default:
152: break;
153: }
154:
155: n = libnet_pblock_append(l, p, (uint8_t *)&cdp_value_hdr, LIBNET_CDP_VALUE_H);
156: if (n == -1)
157: {
158: return (-1);
159: }
160:
161: n = libnet_pblock_append(l, p, value, len);
162: if (n == -1)
163: {
164: /* err msg set in libnet_pblock_append() */
165: return (-1);
166: }
167:
168: return (1);
169: }
170:
171: /**
172: * Local Variables:
173: * indent-tabs-mode: nil
174: * c-file-style: "stroustrup"
175: * End:
176: */
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