Contents of /tags/mkinitrd-6_3_1/busybox/networking/nc.c
Parent Directory | Revision Log
Revision 532 -
(show annotations)
(download)
Sat Sep 1 22:45:15 2007 UTC (17 years ago) by niro
Original Path: trunk/mkinitrd-magellan/busybox/networking/nc.c
File MIME type: text/plain
File size: 5343 byte(s)
Sat Sep 1 22:45:15 2007 UTC (17 years ago) by niro
Original Path: trunk/mkinitrd-magellan/busybox/networking/nc.c
File MIME type: text/plain
File size: 5343 byte(s)
-import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
1 | /* vi: set sw=4 ts=4: */ |
2 | /* nc: mini-netcat - built from the ground up for LRP |
3 | * |
4 | * Copyright (C) 1998, 1999 Charles P. Wright |
5 | * Copyright (C) 1998 Dave Cinege |
6 | * |
7 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
8 | */ |
9 | |
10 | #include "busybox.h" |
11 | |
12 | /* Lots of small differences in features |
13 | * when compared to "standard" nc |
14 | */ |
15 | |
16 | static void timeout(int signum) |
17 | { |
18 | bb_error_msg_and_die("timed out"); |
19 | } |
20 | |
21 | int nc_main(int argc, char **argv) |
22 | { |
23 | /* sfd sits _here_ only because of "repeat" option (-l -l). */ |
24 | int sfd = sfd; /* for gcc */ |
25 | int cfd = 0; |
26 | unsigned lport = 0; |
27 | SKIP_NC_SERVER(const) unsigned do_listen = 0; |
28 | SKIP_NC_EXTRA (const) unsigned wsecs = 0; |
29 | SKIP_NC_EXTRA (const) unsigned delay = 0; |
30 | SKIP_NC_EXTRA (const int execparam = 0;) |
31 | USE_NC_EXTRA (char **execparam = NULL;) |
32 | len_and_sockaddr *lsa; |
33 | fd_set readfds, testfds; |
34 | int opt; /* must be signed (getopt returns -1) */ |
35 | |
36 | if (ENABLE_NC_SERVER || ENABLE_NC_EXTRA) { |
37 | /* getopt32 is _almost_ usable: |
38 | ** it cannot handle "... -e prog -prog-opt" */ |
39 | while ((opt = getopt(argc, argv, |
40 | "" USE_NC_SERVER("lp:") USE_NC_EXTRA("w:i:f:e:") )) > 0 |
41 | ) { |
42 | if (ENABLE_NC_SERVER && opt=='l') USE_NC_SERVER(do_listen++); |
43 | else if (ENABLE_NC_SERVER && opt=='p') { |
44 | USE_NC_SERVER(lport = bb_lookup_port(optarg, "tcp", 0)); |
45 | } |
46 | else if (ENABLE_NC_EXTRA && opt=='w') USE_NC_EXTRA( wsecs = xatou(optarg)); |
47 | else if (ENABLE_NC_EXTRA && opt=='i') USE_NC_EXTRA( delay = xatou(optarg)); |
48 | else if (ENABLE_NC_EXTRA && opt=='f') USE_NC_EXTRA( cfd = xopen(optarg, O_RDWR)); |
49 | else if (ENABLE_NC_EXTRA && opt=='e' && optind<=argc) { |
50 | /* We cannot just 'break'. We should let getopt finish. |
51 | ** Or else we won't be able to find where |
52 | ** 'host' and 'port' params are |
53 | ** (think "nc -w 60 host port -e prog"). */ |
54 | USE_NC_EXTRA( |
55 | char **p; |
56 | // +2: one for progname (optarg) and one for NULL |
57 | execparam = xzalloc(sizeof(char*) * (argc - optind + 2)); |
58 | p = execparam; |
59 | *p++ = optarg; |
60 | while (optind < argc) { |
61 | *p++ = argv[optind++]; |
62 | } |
63 | ) |
64 | /* optind points to argv[arvc] (NULL) now. |
65 | ** FIXME: we assume that getopt will not count options |
66 | ** possibly present on "-e prog args" and will not |
67 | ** include them into final value of optind |
68 | ** which is to be used ... */ |
69 | } else bb_show_usage(); |
70 | } |
71 | argv += optind; /* ... here! */ |
72 | argc -= optind; |
73 | // -l and -f don't mix |
74 | if (do_listen && cfd) bb_show_usage(); |
75 | // Listen or file modes need zero arguments, client mode needs 2 |
76 | if (do_listen || cfd) { |
77 | if (argc) bb_show_usage(); |
78 | } else { |
79 | if (!argc || argc > 2) bb_show_usage(); |
80 | } |
81 | } else { |
82 | if (argc != 3) bb_show_usage(); |
83 | argc--; |
84 | argv++; |
85 | } |
86 | |
87 | if (wsecs) { |
88 | signal(SIGALRM, timeout); |
89 | alarm(wsecs); |
90 | } |
91 | |
92 | if (!cfd) { |
93 | if (do_listen) { |
94 | socklen_t addrlen; |
95 | |
96 | /* create_and_bind_stream_or_die(NULL, lport) |
97 | * would've work wonderfully, but we need |
98 | * to know lsa */ |
99 | sfd = xsocket_stream(&lsa); |
100 | if (lport) |
101 | set_nport(lsa, htons(lport)); |
102 | setsockopt_reuseaddr(sfd); |
103 | xbind(sfd, &lsa->sa, lsa->len); |
104 | xlisten(sfd, do_listen); /* can be > 1 */ |
105 | /* If we didn't specify a port number, |
106 | * query and print it after listen() */ |
107 | if (!lport) { |
108 | addrlen = lsa->len; |
109 | getsockname(sfd, &lsa->sa, &addrlen); |
110 | lport = get_nport(lsa); |
111 | fdprintf(2, "%d\n", ntohs(lport)); |
112 | } |
113 | fcntl(sfd, F_SETFD, FD_CLOEXEC); |
114 | accept_again: |
115 | addrlen = lsa->len; |
116 | cfd = accept(sfd, NULL, 0); /* &lsa->sa, &addrlen); */ |
117 | if (cfd < 0) |
118 | bb_perror_msg_and_die("accept"); |
119 | if (!execparam) |
120 | close(sfd); |
121 | } else { |
122 | cfd = create_and_connect_stream_or_die(argv[0], |
123 | argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 0); |
124 | } |
125 | } |
126 | |
127 | if (wsecs) { |
128 | alarm(0); |
129 | signal(SIGALRM, SIG_DFL); |
130 | } |
131 | |
132 | /* -e given? */ |
133 | if (execparam) { |
134 | signal(SIGCHLD, SIG_IGN); |
135 | // With more than one -l, repeatedly act as server. |
136 | if (do_listen > 1 && vfork()) { |
137 | /* parent */ |
138 | // This is a bit weird as cleanup goes, since we wind up with no |
139 | // stdin/stdout/stderr. But it's small and shouldn't hurt anything. |
140 | // We check for cfd == 0 above. |
141 | logmode = LOGMODE_NONE; |
142 | close(0); |
143 | close(1); |
144 | close(2); |
145 | goto accept_again; |
146 | } |
147 | /* child (or main thread if no multiple -l) */ |
148 | if (cfd) { |
149 | dup2(cfd, 0); |
150 | close(cfd); |
151 | } |
152 | dup2(0, 1); |
153 | dup2(0, 2); |
154 | USE_NC_EXTRA(execvp(execparam[0], execparam);) |
155 | /* Don't print stuff or it will go over the wire.... */ |
156 | _exit(127); |
157 | } |
158 | |
159 | // Select loop copying stdin to cfd, and cfd to stdout. |
160 | |
161 | FD_ZERO(&readfds); |
162 | FD_SET(cfd, &readfds); |
163 | FD_SET(STDIN_FILENO, &readfds); |
164 | |
165 | for (;;) { |
166 | int fd; |
167 | int ofd; |
168 | int nread; |
169 | |
170 | testfds = readfds; |
171 | |
172 | if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0) |
173 | bb_perror_msg_and_die("select"); |
174 | |
175 | for (fd = 0; fd < FD_SETSIZE; fd++) { |
176 | if (FD_ISSET(fd, &testfds)) { |
177 | nread = safe_read(fd, bb_common_bufsiz1, |
178 | sizeof(bb_common_bufsiz1)); |
179 | |
180 | if (fd == cfd) { |
181 | if (nread < 1) |
182 | exit(0); |
183 | ofd = STDOUT_FILENO; |
184 | } else { |
185 | if (nread<1) { |
186 | // Close outgoing half-connection so they get EOF, but |
187 | // leave incoming alone so we can see response. |
188 | shutdown(cfd, 1); |
189 | FD_CLR(STDIN_FILENO, &readfds); |
190 | } |
191 | ofd = cfd; |
192 | } |
193 | |
194 | xwrite(ofd, bb_common_bufsiz1, nread); |
195 | if (delay > 0) sleep(delay); |
196 | } |
197 | } |
198 | } |
199 | } |