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