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Diffstat (limited to 'term-utils/wall.c')
| -rw-r--r-- | term-utils/wall.c | 448 |
1 files changed, 448 insertions, 0 deletions
diff --git a/term-utils/wall.c b/term-utils/wall.c new file mode 100644 index 0000000..48e654a --- /dev/null +++ b/term-utils/wall.c @@ -0,0 +1,448 @@ +/* + * Copyright (c) 1988, 1990, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * Modified Sun Mar 12 10:34:34 1995, faith@cs.unc.edu, for Linux + */ + +/* + * This program is not related to David Wall, whose Stanford Ph.D. thesis + * is entitled "Mechanisms for Broadcast and Selective Broadcast". + * + * 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL> + * - added Native Language Support + * + */ + +#include <sys/param.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/uio.h> + +#include <errno.h> +#include <paths.h> +#include <ctype.h> +#include <pwd.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <unistd.h> +#include <utmpx.h> +#include <getopt.h> +#include <sys/types.h> +#include <grp.h> + +#include "nls.h" +#include "xalloc.h" +#include "strutils.h" +#include "ttymsg.h" +#include "pathnames.h" +#include "carefulputc.h" +#include "c.h" +#include "fileutils.h" +#include "closestream.h" + +#define TERM_WIDTH 79 +#define WRITE_TIME_OUT 300 /* in seconds */ + +/* Function prototypes */ +static char *makemsg(char *fname, char **mvec, int mvecsz, + size_t *mbufsize, int print_banner); + +static void __attribute__((__noreturn__)) usage(void) +{ + FILE *out = stdout; + fputs(USAGE_HEADER, out); + fprintf(out, + _(" %s [options] [<file> | <message>]\n"), program_invocation_short_name); + + fputs(USAGE_SEPARATOR, out); + fputs(_("Write a message to all users.\n"), out); + + fputs(USAGE_OPTIONS, out); + fputs(_(" -g, --group <group> only send message to group\n"), out); + fputs(_(" -n, --nobanner do not print banner, works only for root\n"), out); + fputs(_(" -t, --timeout <timeout> write timeout in seconds\n"), out); + fputs(USAGE_SEPARATOR, out); + printf(USAGE_HELP_OPTIONS(25)); + printf(USAGE_MAN_TAIL("wall(1)")); + + exit(EXIT_SUCCESS); +} + +struct group_workspace { + gid_t requested_group; + int ngroups; + +/* getgrouplist() on OSX takes int* not gid_t* */ +#ifdef __APPLE__ + int *groups; +#else + gid_t *groups; +#endif +}; + +static gid_t get_group_gid(const char *optarg) +{ + struct group *gr; + gid_t gid; + + if ((gr = getgrnam(optarg))) + return gr->gr_gid; + + gid = strtou32_or_err(optarg, _("invalid group argument")); + if (!getgrgid(gid)) + errx(EXIT_FAILURE, _("%s: unknown gid"), optarg); + + return gid; +} + +static struct group_workspace *init_group_workspace(const char *optarg) +{ + struct group_workspace *buf = xmalloc(sizeof(struct group_workspace)); + + buf->requested_group = get_group_gid(optarg); + buf->ngroups = sysconf(_SC_NGROUPS_MAX) + 1; /* room for the primary gid */ + buf->groups = xcalloc(sizeof(*buf->groups), buf->ngroups); + + return buf; +} + +static void free_group_workspace(struct group_workspace *buf) +{ + if (!buf) + return; + + free(buf->groups); + free(buf); +} + +static int is_gr_member(const char *login, const struct group_workspace *buf) +{ + struct passwd *pw; + int ngroups = buf->ngroups; + int rc; + + pw = getpwnam(login); + if (!pw) + return 0; + + if (buf->requested_group == pw->pw_gid) + return 1; + + rc = getgrouplist(login, pw->pw_gid, buf->groups, &ngroups); + if (rc < 0) { + /* buffer too small, not sure how this can happen, since + we used sysconf to get the size... */ + errx(EXIT_FAILURE, + _("getgrouplist found more groups than sysconf allows")); + } + + for (; ngroups >= 0; --ngroups) { + if (buf->requested_group == (gid_t) buf->groups[ngroups]) + return 1; + } + + return 0; +} + +int main(int argc, char **argv) +{ + int ch; + struct iovec iov; + struct utmpx *utmpptr; + char *p; + char line[sizeof(utmpptr->ut_line) + 1]; + int print_banner = TRUE; + struct group_workspace *group_buf = NULL; + char *mbuf, *fname = NULL; + size_t mbufsize; + unsigned timeout = WRITE_TIME_OUT; + char **mvec = NULL; + int mvecsz = 0; + + static const struct option longopts[] = { + { "nobanner", no_argument, NULL, 'n' }, + { "timeout", required_argument, NULL, 't' }, + { "group", required_argument, NULL, 'g' }, + { "version", no_argument, NULL, 'V' }, + { "help", no_argument, NULL, 'h' }, + { NULL, 0, NULL, 0 } + }; + + setlocale(LC_ALL, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + atexit(close_stdout); + + while ((ch = getopt_long(argc, argv, "nt:g:Vh", longopts, NULL)) != -1) { + switch (ch) { + case 'n': + if (geteuid() == 0) + print_banner = FALSE; + else + warnx(_("--nobanner is available only for root")); + break; + case 't': + timeout = strtou32_or_err(optarg, _("invalid timeout argument")); + if (timeout < 1) + errx(EXIT_FAILURE, _("invalid timeout argument: %s"), optarg); + break; + case 'g': + group_buf = init_group_workspace(optarg); + break; + case 'V': + printf(UTIL_LINUX_VERSION); + exit(EXIT_SUCCESS); + case 'h': + usage(); + default: + errtryhelp(EXIT_FAILURE); + } + } + argc -= optind; + argv += optind; + + if (argc == 1 && access(argv[0], F_OK) == 0) + fname = argv[0]; + else if (argc >= 1) { + mvec = argv; + mvecsz = argc; + } + + mbuf = makemsg(fname, mvec, mvecsz, &mbufsize, print_banner); + + iov.iov_base = mbuf; + iov.iov_len = mbufsize; + while((utmpptr = getutxent())) { + if (!utmpptr->ut_user[0]) + continue; +#ifdef USER_PROCESS + if (utmpptr->ut_type != USER_PROCESS) + continue; +#endif + /* Joey Hess reports that use-sessreg in /etc/X11/wdm/ + produces ut_line entries like :0, and a write + to /dev/:0 fails. */ + if (utmpptr->ut_line[0] == ':') + continue; + + if (group_buf && !is_gr_member(utmpptr->ut_user, group_buf)) + continue; + + mem2strcpy(line, utmpptr->ut_line, sizeof(utmpptr->ut_line), sizeof(line)); + if ((p = ttymsg(&iov, 1, line, timeout)) != NULL) + warnx("%s", p); + } + endutxent(); + free(mbuf); + free_group_workspace(group_buf); + exit(EXIT_SUCCESS); +} + +struct buffer { + size_t sz; + size_t used; + char *data; +}; + +static void buf_enlarge(struct buffer *bs, size_t len) +{ + if (bs->sz == 0 || len > bs->sz - bs->used) { + bs->sz += len < 128 ? 128 : len; + bs->data = xrealloc(bs->data, bs->sz); + } +} + +static void buf_puts(struct buffer *bs, const char *s) +{ + size_t len = strlen(s); + + buf_enlarge(bs, len + 1); + memcpy(bs->data + bs->used, s, len + 1); + bs->used += len; +} + +static void buf_printf(struct buffer *bs, const char *fmt, ...) +{ + int rc; + va_list ap; + size_t limit; + + buf_enlarge(bs, 0); /* default size */ + limit = bs->sz - bs->used; + + va_start(ap, fmt); + rc = vsnprintf(bs->data + bs->used, limit, fmt, ap); + va_end(ap); + + if (rc >= 0 && (size_t) rc >= limit) { /* not enough, enlarge */ + buf_enlarge(bs, (size_t)rc + 1); + limit = bs->sz - bs->used; + va_start(ap, fmt); + rc = vsnprintf(bs->data + bs->used, limit, fmt, ap); + va_end(ap); + } + + if (rc > 0) + bs->used += rc; +} + +static void buf_putc_careful(struct buffer *bs, int c) +{ + if (isprint(c) || c == '\a' || c == '\t' || c == '\r' || c == '\n') { + buf_enlarge(bs, 1); + bs->data[bs->used++] = c; + } else if (!isascii(c)) + buf_printf(bs, "\\%3o", (unsigned char)c); + else { + char tmp[] = { '^', c ^ 0x40, '\0' }; + buf_puts(bs, tmp); + } +} + +static char *makemsg(char *fname, char **mvec, int mvecsz, + size_t *mbufsize, int print_banner) +{ + struct buffer _bs = {.used = 0}, *bs = &_bs; + register int ch, cnt; + char *p, *lbuf; + long line_max; + + line_max = sysconf(_SC_LINE_MAX); + if (line_max <= 0) + line_max = 512; + + lbuf = xmalloc(line_max); + + if (print_banner == TRUE) { + char *hostname = xgethostname(); + char *whom, *where, *date; + struct passwd *pw; + time_t now; + + if (!(whom = getlogin()) || !*whom) + whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; + if (!whom) { + whom = "someone"; + warn(_("cannot get passwd uid")); + } + where = ttyname(STDOUT_FILENO); + if (!where) { + where = "somewhere"; + warn(_("cannot get tty name")); + } else if (strncmp(where, "/dev/", 5) == 0) + where += 5; + + time(&now); + date = xstrdup(ctime(&now)); + date[strlen(date) - 1] = '\0'; + + /* + * all this stuff is to blank out a square for the message; + * we wrap message lines at column 79, not 80, because some + * terminals wrap after 79, some do not, and we can't tell. + * Which means that we may leave a non-blank character + * in column 80, but that can't be helped. + */ + /* snprintf is not always available, but the sprintf's here + will not overflow as long as %d takes at most 100 chars */ + buf_printf(bs, "\r%*s\r\n", TERM_WIDTH, " "); + + snprintf(lbuf, line_max, + _("Broadcast message from %s@%s (%s) (%s):"), + whom, hostname, where, date); + buf_printf(bs, "%-*.*s\007\007\r\n", TERM_WIDTH, TERM_WIDTH, lbuf); + free(hostname); + free(date); + } + buf_printf(bs, "%*s\r\n", TERM_WIDTH, " "); + + if (mvec) { + /* + * Read message from argv[] + */ + int i; + + for (i = 0; i < mvecsz; i++) { + buf_puts(bs, mvec[i]); + if (i < mvecsz - 1) + buf_puts(bs, " "); + } + buf_puts(bs, "\r\n"); + } else { + /* + * read message from <file> + */ + if (fname) { + /* + * When we are not root, but suid or sgid, refuse to read files + * (e.g. device files) that the user may not have access to. + * After all, our invoker can easily do "wall < file" + * instead of "wall file". + */ + uid_t uid = getuid(); + if (uid && (uid != geteuid() || getgid() != getegid())) + errx(EXIT_FAILURE, _("will not read %s - use stdin."), + fname); + + if (!freopen(fname, "r", stdin)) + err(EXIT_FAILURE, _("cannot open %s"), fname); + + } + + /* + * Read message from stdin. + */ + while (fgets(lbuf, line_max, stdin)) { + for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { + if (cnt == TERM_WIDTH || ch == '\n') { + for (; cnt < TERM_WIDTH; ++cnt) + buf_puts(bs, " "); + buf_puts(bs, "\r\n"); + cnt = 0; + } + if (ch == '\t') + cnt += (7 - (cnt % 8)); + if (ch != '\n') + buf_putc_careful(bs, ch); + } + } + } + buf_printf(bs, "%*s\r\n", TERM_WIDTH, " "); + + free(lbuf); + + bs->data[bs->used] = '\0'; /* be paranoid */ + *mbufsize = bs->used; + return bs->data; +} |