Contents of /tags/mkinitrd-6_2_1/busybox/networking/nc.c
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Sun May 30 12:16:23 2010 UTC (14 years, 4 months ago) by niro
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Sun May 30 12:16:23 2010 UTC (14 years, 4 months ago) by niro
File MIME type: text/plain
File size: 5326 byte(s)
tagged 'mkinitrd-6_2_1'
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 "libbb.h" |
11 | |
12 | #if ENABLE_DESKTOP |
13 | #include "nc_bloaty.c" |
14 | #else |
15 | |
16 | /* Lots of small differences in features |
17 | * when compared to "standard" nc |
18 | */ |
19 | |
20 | static void timeout(int signum UNUSED_PARAM) |
21 | { |
22 | bb_error_msg_and_die("timed out"); |
23 | } |
24 | |
25 | int nc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
26 | int nc_main(int argc, char **argv) |
27 | { |
28 | /* sfd sits _here_ only because of "repeat" option (-l -l). */ |
29 | int sfd = sfd; /* for gcc */ |
30 | int cfd = 0; |
31 | unsigned lport = 0; |
32 | IF_NOT_NC_SERVER(const) unsigned do_listen = 0; |
33 | IF_NOT_NC_EXTRA (const) unsigned wsecs = 0; |
34 | IF_NOT_NC_EXTRA (const) unsigned delay = 0; |
35 | IF_NOT_NC_EXTRA (const int execparam = 0;) |
36 | IF_NC_EXTRA (char **execparam = NULL;) |
37 | fd_set readfds, testfds; |
38 | int opt; /* must be signed (getopt returns -1) */ |
39 | |
40 | if (ENABLE_NC_SERVER || ENABLE_NC_EXTRA) { |
41 | /* getopt32 is _almost_ usable: |
42 | ** it cannot handle "... -e prog -prog-opt" */ |
43 | while ((opt = getopt(argc, argv, |
44 | "" IF_NC_SERVER("lp:") IF_NC_EXTRA("w:i:f:e:") )) > 0 |
45 | ) { |
46 | if (ENABLE_NC_SERVER && opt == 'l') |
47 | IF_NC_SERVER(do_listen++); |
48 | else if (ENABLE_NC_SERVER && opt == 'p') |
49 | IF_NC_SERVER(lport = bb_lookup_port(optarg, "tcp", 0)); |
50 | else if (ENABLE_NC_EXTRA && opt == 'w') |
51 | IF_NC_EXTRA( wsecs = xatou(optarg)); |
52 | else if (ENABLE_NC_EXTRA && opt == 'i') |
53 | IF_NC_EXTRA( delay = xatou(optarg)); |
54 | else if (ENABLE_NC_EXTRA && opt == 'f') |
55 | IF_NC_EXTRA( cfd = xopen(optarg, O_RDWR)); |
56 | else if (ENABLE_NC_EXTRA && opt == 'e' && optind <= argc) { |
57 | /* We cannot just 'break'. We should let getopt finish. |
58 | ** Or else we won't be able to find where |
59 | ** 'host' and 'port' params are |
60 | ** (think "nc -w 60 host port -e prog"). */ |
61 | IF_NC_EXTRA( |
62 | char **p; |
63 | // +2: one for progname (optarg) and one for NULL |
64 | execparam = xzalloc(sizeof(char*) * (argc - optind + 2)); |
65 | p = execparam; |
66 | *p++ = optarg; |
67 | while (optind < argc) { |
68 | *p++ = argv[optind++]; |
69 | } |
70 | ) |
71 | /* optind points to argv[arvc] (NULL) now. |
72 | ** FIXME: we assume that getopt will not count options |
73 | ** possibly present on "-e prog args" and will not |
74 | ** include them into final value of optind |
75 | ** which is to be used ... */ |
76 | } else bb_show_usage(); |
77 | } |
78 | argv += optind; /* ... here! */ |
79 | argc -= optind; |
80 | // -l and -f don't mix |
81 | if (do_listen && cfd) bb_show_usage(); |
82 | // File mode needs need zero arguments, listen mode needs zero or one, |
83 | // client mode needs one or two |
84 | if (cfd) { |
85 | if (argc) bb_show_usage(); |
86 | } else if (do_listen) { |
87 | if (argc > 1) bb_show_usage(); |
88 | } else { |
89 | if (!argc || argc > 2) bb_show_usage(); |
90 | } |
91 | } else { |
92 | if (argc != 3) bb_show_usage(); |
93 | argc--; |
94 | argv++; |
95 | } |
96 | |
97 | if (wsecs) { |
98 | signal(SIGALRM, timeout); |
99 | alarm(wsecs); |
100 | } |
101 | |
102 | if (!cfd) { |
103 | if (do_listen) { |
104 | sfd = create_and_bind_stream_or_die(argv[0], lport); |
105 | xlisten(sfd, do_listen); /* can be > 1 */ |
106 | #if 0 /* nc-1.10 does not do this (without -v) */ |
107 | /* If we didn't specify a port number, |
108 | * query and print it after listen() */ |
109 | if (!lport) { |
110 | len_and_sockaddr lsa; |
111 | lsa.len = LSA_SIZEOF_SA; |
112 | getsockname(sfd, &lsa.u.sa, &lsa.len); |
113 | lport = get_nport(&lsa.u.sa); |
114 | fdprintf(2, "%d\n", ntohs(lport)); |
115 | } |
116 | #endif |
117 | close_on_exec_on(sfd); |
118 | accept_again: |
119 | cfd = accept(sfd, NULL, 0); |
120 | if (cfd < 0) |
121 | bb_perror_msg_and_die("accept"); |
122 | if (!execparam) |
123 | close(sfd); |
124 | } else { |
125 | cfd = create_and_connect_stream_or_die(argv[0], |
126 | argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 0); |
127 | } |
128 | } |
129 | |
130 | if (wsecs) { |
131 | alarm(0); |
132 | /* Non-ignored signals revert to SIG_DFL on exec anyway */ |
133 | /*signal(SIGALRM, SIG_DFL);*/ |
134 | } |
135 | |
136 | /* -e given? */ |
137 | if (execparam) { |
138 | pid_t pid; |
139 | /* With more than one -l, repeatedly act as server */ |
140 | if (do_listen > 1 && (pid = vfork()) != 0) { |
141 | /* parent or error */ |
142 | if (pid < 0) |
143 | bb_perror_msg_and_die("vfork"); |
144 | /* prevent zombies */ |
145 | signal(SIGCHLD, SIG_IGN); |
146 | close(cfd); |
147 | goto accept_again; |
148 | } |
149 | /* child, or main thread if only one -l */ |
150 | xmove_fd(cfd, 0); |
151 | xdup2(0, 1); |
152 | xdup2(0, 2); |
153 | IF_NC_EXTRA(BB_EXECVP(execparam[0], execparam);) |
154 | /* Don't print stuff or it will go over the wire... */ |
155 | _exit(127); |
156 | } |
157 | |
158 | /* Select loop copying stdin to cfd, and cfd to stdout */ |
159 | |
160 | FD_ZERO(&readfds); |
161 | FD_SET(cfd, &readfds); |
162 | FD_SET(STDIN_FILENO, &readfds); |
163 | |
164 | for (;;) { |
165 | int fd; |
166 | int ofd; |
167 | int nread; |
168 | |
169 | testfds = readfds; |
170 | |
171 | if (select(cfd + 1, &testfds, NULL, NULL, NULL) < 0) |
172 | bb_perror_msg_and_die("select"); |
173 | |
174 | #define iobuf bb_common_bufsiz1 |
175 | fd = STDIN_FILENO; |
176 | while (1) { |
177 | if (FD_ISSET(fd, &testfds)) { |
178 | nread = safe_read(fd, iobuf, sizeof(iobuf)); |
179 | if (fd == cfd) { |
180 | if (nread < 1) |
181 | exit(EXIT_SUCCESS); |
182 | ofd = STDOUT_FILENO; |
183 | } else { |
184 | if (nread < 1) { |
185 | /* Close outgoing half-connection so they get EOF, |
186 | * but leave incoming alone so we can see response */ |
187 | shutdown(cfd, 1); |
188 | FD_CLR(STDIN_FILENO, &readfds); |
189 | } |
190 | ofd = cfd; |
191 | } |
192 | xwrite(ofd, iobuf, nread); |
193 | if (delay > 0) |
194 | sleep(delay); |
195 | } |
196 | if (fd == cfd) |
197 | break; |
198 | fd = cfd; |
199 | } |
200 | } |
201 | } |
202 | #endif |