1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Tony Nardo of the Johns Hopkins University/Applied Physics Lab. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)net.c 8.4 (Berkeley) 4/28/95 37 * $FreeBSD: src/usr.bin/finger/net.c,v 1.12.2.4 2002/12/16 08:41:28 roam Exp $ 38 * $DragonFly: src/usr.bin/finger/net.c,v 1.5 2004/09/03 19:13:23 dillon Exp $ 39 */ 40 41 #include <sys/param.h> 42 #include <sys/socket.h> 43 #include <sys/uio.h> 44 #include <ctype.h> 45 #include <db.h> 46 #include <err.h> 47 #include <netdb.h> 48 #include <pwd.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 #include <utmp.h> 54 #include "finger.h" 55 56 static void cleanup(int sig); 57 static int do_protocol(const char *name, const struct addrinfo *ai); 58 static void trying(const struct addrinfo *ai); 59 60 void 61 netfinger(char *name) 62 { 63 int error, multi; 64 char *host; 65 struct addrinfo *ai, *ai0; 66 static struct addrinfo hint; 67 68 host = strrchr(name, '@'); 69 if (host == 0) 70 return; 71 *host++ = '\0'; 72 signal(SIGALRM, cleanup); 73 alarm(TIME_LIMIT); 74 75 hint.ai_flags = AI_CANONNAME; 76 hint.ai_family = family; 77 hint.ai_socktype = SOCK_STREAM; 78 79 error = getaddrinfo(host, "finger", &hint, &ai0); 80 if (error) { 81 warnx("%s: %s", host, gai_strerror(error)); 82 return; 83 } 84 85 multi = (ai0->ai_next) != 0; 86 87 /* ai_canonname may not be filled in if the user specified an IP. */ 88 if (ai0->ai_canonname == 0) 89 printf("[%s]\n", host); 90 else 91 printf("[%s]\n", ai0->ai_canonname); 92 93 for (ai = ai0; ai != 0; ai = ai->ai_next) { 94 if (multi) 95 trying(ai); 96 97 error = do_protocol(name, ai); 98 if (!error) 99 break; 100 } 101 alarm(0); 102 freeaddrinfo(ai0); 103 } 104 105 static int 106 do_protocol(const char *name, const struct addrinfo *ai) 107 { 108 int cnt, line_len, s; 109 FILE *fp; 110 int c, lastc; 111 struct iovec iov[3]; 112 struct msghdr msg; 113 static char slash_w[] = "/W "; 114 static char neteol[] = "\r\n"; 115 116 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); 117 if (s < 0) { 118 warn("socket(%d, %d, %d)", ai->ai_family, ai->ai_socktype, 119 ai->ai_protocol); 120 return -1; 121 } 122 123 msg.msg_name = (void *)ai->ai_addr; 124 msg.msg_namelen = ai->ai_addrlen; 125 msg.msg_iov = iov; 126 msg.msg_iovlen = 0; 127 msg.msg_control = 0; 128 msg.msg_controllen = 0; 129 msg.msg_flags = 0; 130 131 /* -l flag for remote fingerd */ 132 if (lflag) { 133 iov[msg.msg_iovlen].iov_base = slash_w; 134 iov[msg.msg_iovlen++].iov_len = 3; 135 } 136 /* send the name followed by <CR><LF> */ 137 iov[msg.msg_iovlen].iov_base = strdup(name); 138 iov[msg.msg_iovlen++].iov_len = strlen(name); 139 iov[msg.msg_iovlen].iov_base = neteol; 140 iov[msg.msg_iovlen++].iov_len = 2; 141 142 /* 143 * -T disables data-on-SYN: compatibility option to finger broken 144 * hosts. Also, the implicit-open API is broken on IPv6, so do 145 * the explicit connect there, too. 146 */ 147 if ((Tflag || ai->ai_addr->sa_family == AF_INET6) 148 && connect(s, ai->ai_addr, ai->ai_addrlen) < 0) { 149 warn("connect"); 150 close(s); 151 return -1; 152 } 153 154 if (sendmsg(s, &msg, 0) < 0) { 155 warn("sendmsg"); 156 close(s); 157 return -1; 158 } 159 160 /* 161 * Read from the remote system; once we're connected, we assume some 162 * data. If none arrives, we hang until the user interrupts. 163 * 164 * If we see a <CR> or a <CR> with the high bit set, treat it as 165 * a newline; if followed by a newline character, only output one 166 * newline. 167 * 168 * Otherwise, all high bits are stripped; if it isn't printable and 169 * it isn't a space, we can simply set the 7th bit. Every ASCII 170 * character with bit 7 set is printable. 171 */ 172 lastc = 0; 173 if ((fp = fdopen(s, "r")) != NULL) { 174 cnt = 0; 175 line_len = 0; 176 while ((c = getc(fp)) != EOF) { 177 if (++cnt > OUTPUT_MAX) { 178 printf("\n\n Output truncated at %d bytes...\n", 179 cnt - 1); 180 break; 181 } 182 if (c == 0x0d) { 183 if (lastc == '\r') /* ^M^M - skip dupes */ 184 continue; 185 c = '\n'; 186 lastc = '\r'; 187 } else { 188 if (!(eightflag || isprint(c) || isspace(c))) { 189 c &= 0x7f; 190 c |= 0x40; 191 } 192 if (lastc != '\r' || c != '\n') 193 lastc = c; 194 else { 195 lastc = '\n'; 196 continue; 197 } 198 } 199 putchar(c); 200 if (c != '\n' && ++line_len > _POSIX2_LINE_MAX) { 201 putchar('\\'); 202 putchar('\n'); 203 lastc = '\r'; 204 } 205 if (lastc == '\n' || lastc == '\r') 206 line_len = 0; 207 } 208 if (ferror(fp)) { 209 /* 210 * Assume that whatever it was set errno... 211 */ 212 warn("reading from network"); 213 } 214 if (lastc != '\n') 215 putchar('\n'); 216 217 fclose(fp); 218 } 219 return 0; 220 } 221 222 static void 223 trying(const struct addrinfo *ai) 224 { 225 char buf[NI_MAXHOST]; 226 227 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, buf, sizeof buf, 228 NULL, 0, NI_NUMERICHOST) != 0) 229 return; /* XXX can't happen */ 230 231 printf("Trying %s...\n", buf); 232 } 233 234 void 235 cleanup(int sig __unused) 236 { 237 #define ERRSTR "Timed out.\n" 238 write(STDERR_FILENO, ERRSTR, sizeof ERRSTR); 239 exit(1); 240 } 241 242