nexmon – Blame information for rev 1

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1 office 1 /*
2 * Stanford Enetfilter subroutines for tcpdump
3 *
4 * Based on the MERIT NNstat etherifrt.c and the Ultrix pcap-pf.c
5 * subroutines.
6 *
7 * Rayan Zachariassen, CA*Net
8 */
9  
10 #ifdef HAVE_CONFIG_H
11 #include "config.h"
12 #endif
13  
14 #include <sys/types.h>
15 #include <sys/time.h>
16 #include <sys/file.h>
17 #include <sys/ioctl.h>
18 #include <sys/socket.h>
19  
20 #include <net/if.h>
21 #include <pcap/bpf.h>
22 #include <net/enet.h>
23  
24 #include <netinet/in.h>
25 #include <netinet/if_ether.h>
26  
27 #include <stdio.h>
28 #include <errno.h>
29  
30 #include "interface.h"
31  
32 struct packet_header {
33 #ifdef IBMRTPC
34 struct LengthWords length;
35 struct tap_header tap;
36 #endif /* IBMRTPC */
37 u_char packet[8]
38 };
39  
40 extern int errno;
41  
42 #define BUFSPACE (4*1024)
43  
44 /* Forwards */
45 static void efReadError(int, char *);
46  
47 void
48 readloop(int cnt, int if_fd, struct bpf_program *fp, printfunc printit)
49 {
50 #ifdef IBMRTPC
51 register struct packet_header *ph;
52 register u_char *bp;
53 register int inc;
54 #else /* !IBMRTPC */
55 static struct timeval tv = { 0 };
56 #endif /* IBMRTPC */
57 register int cc, caplen;
58 register struct bpf_insn *fcode = fp->bf_insns;
59 union {
60 struct packet_header hdr;
61 u_char p[BUFSPACE];
62 u_short s;
63 } buf;
64  
65 while (1) {
66 if ((cc = read(if_fd, (char *)buf.p, sizeof(buf))) < 0)
67 efReadError(if_fd, "reader");
68  
69 #ifdef IBMRTPC
70 /*
71 * Loop through each packet.
72 */
73 bp = buf.p;
74 while (cc > 0) {
75 ph = (struct packet_header *)bp;
76 caplen = ph->tap.th_wirelen > snaplen ? snaplen : ph->tap
77 .th_wirelen ;
78 if (bpf_filter(fcode, (char *)ph->packet,
79 ph->tap.th_wirelen, caplen)) {
80 if (cnt >= 0 && --cnt < 0)
81 goto out;
82 (*printit)((char *)ph->packet,
83 (struct timeval *)ph->tap.th_timestamp,
84 ph->tap.th_wirelen, caplen);
85 }
86 inc = ph->length.PacketOffset;
87 cc -= inc;
88 bp += inc;
89 }
90 #else /* !IBMRTPC */
91 caplen = cc > snaplen ? snaplen : cc ;
92 if (bpf_filter(fcode, buf.hdr.packet, cc, caplen)) {
93 if (cnt >= 0 && --cnt < 0)
94 goto out;
95 (*printit)(buf.hdr.packet, &tv, cc, caplen);
96 }
97 #endif /* IBMRTPC */
98 }
99 out:
100 wrapup(if_fd);
101 }
102  
103 /* Call ONLY if read() has returned an error on packet filter */
104 static void
105 efReadError(int fid, char *msg)
106 {
107 if (errno == EINVAL) { /* read MAXINT bytes already! */
108 if (lseek(fid, 0, 0) < 0) {
109 perror("tcpdump: efReadError/lseek");
110 exit(-1);
111 }
112 else
113 return;
114 }
115 else {
116 (void) fprintf(stderr, "tcpdump: ");
117 perror(msg);
118 exit(-1);
119 }
120 }
121  
122 void
123 wrapup(int fd)
124 {
125 #ifdef IBMRTPC
126 struct enstats es;
127  
128 if (ioctl(fd, EIOSTATS, &es) == -1) {
129 perror("tcpdump: enet ioctl EIOSTATS error");
130 exit(-1);
131 }
132  
133 fprintf(stderr, "%d packets queued", es.enStat_Rcnt);
134 if (es.enStat_Rdrops > 0)
135 fprintf(stderr, ", %d dropped", es.enStat_Rdrops);
136 if (es.enStat_Reads > 0)
137 fprintf(stderr, ", %d tcpdump %s", es.enStat_Reads,
138 es.enStat_Reads > 1 ? "reads" : "read");
139 if (es.enStat_MaxRead > 1)
140 fprintf(stderr, ", %d packets in largest read",
141 es.enStat_MaxRead);
142 putc('\n', stderr);
143 #endif /* IBMRTPC */
144 close(fd);
145 }
146  
147 int
148 initdevice(char *device, int pflag, int *linktype)
149 {
150 struct eniocb ctl;
151 struct enfilter filter;
152 u_int maxwaiting;
153 int if_fd;
154  
155 #ifdef IBMRTPC
156 GETENETDEVICE(0, O_RDONLY, &if_fd);
157 #else /* !IBMRTPC */
158 if_fd = open("/dev/enet", O_RDONLY, 0);
159 #endif /* IBMRTPC */
160  
161 if (if_fd == -1) {
162 perror("tcpdump: enet open error");
163 error(
164 "your system may not be properly configured; see \"man enet(4)\"");
165 exit(-1);
166 }
167  
168 /* Get operating parameters. */
169  
170 if (ioctl(if_fd, EIOCGETP, (char *)&ctl) == -1) {
171 perror("tcpdump: enet ioctl EIOCGETP error");
172 exit(-1);
173 }
174  
175 /* Set operating parameters. */
176  
177 #ifdef IBMRTPC
178 ctl.en_rtout = 1 * ctl.en_hz;
179 ctl.en_tr_etherhead = 1;
180 ctl.en_tap_network = 1;
181 ctl.en_multi_packet = 1;
182 ctl.en_maxlen = BUFSPACE;
183 #else /* !IBMRTPC */
184 ctl.en_rtout = 64; /* randomly picked value for HZ */
185 #endif /* IBMRTPC */
186 if (ioctl(if_fd, EIOCSETP, &ctl) == -1) {
187 perror("tcpdump: enet ioctl EIOCSETP error");
188 exit(-1);
189 }
190  
191 /* Flush the receive queue, since we've changed
192 the operating parameters and we otherwise might
193 receive data without headers. */
194  
195 if (ioctl(if_fd, EIOCFLUSH) == -1) {
196 perror("tcpdump: enet ioctl EIOCFLUSH error");
197 exit(-1);
198 }
199  
200 /* Set the receive queue depth to its maximum. */
201  
202 maxwaiting = ctl.en_maxwaiting;
203 if (ioctl(if_fd, EIOCSETW, &maxwaiting) == -1) {
204 perror("tcpdump: enet ioctl EIOCSETW error");
205 exit(-1);
206 }
207  
208 #ifdef IBMRTPC
209 /* Clear statistics. */
210  
211 if (ioctl(if_fd, EIOCLRSTAT, 0) == -1) {
212 perror("tcpdump: enet ioctl EIOCLRSTAT error");
213 exit(-1);
214 }
215 #endif /* IBMRTPC */
216  
217 /* Set the filter (accept all packets). */
218  
219 filter.enf_Priority = 3;
220 filter.enf_FilterLen = 0;
221 if (ioctl(if_fd, EIOCSETF, &filter) == -1) {
222 perror("tcpdump: enet ioctl EIOCSETF error");
223 exit(-1);
224 }
225 /*
226 * "enetfilter" supports only ethernets.
227 */
228 *linktype = DLT_EN10MB;
229  
230 return(if_fd);
231 }