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#include <bglibs/sysdeps.h>
#include <errno.h>
#include <pwd.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <bglibs/iobuf.h>
#include <bglibs/ucspi.h>
#include <bglibs/msg.h>
#include <bglibs/path.h>
#include <bglibs/str.h>
#include <bglibs/trigger.h>
#include "bcron.h"
const char program[] = "bcron-spool";
const int msg_show_pid = 1;
static str filename;
static const char* username;
static char** fixup_argv;
static void respond(const char* msg)
{
obuf_putnetstring(&outbuf, msg, strlen(msg));
obuf_flush(&outbuf);
switch (msg[0]) {
case 'K':
exit(0);
case 'Z':
die3sys(111, username, ": ", msg + 1);
default:
die3(100, username, ": ", msg + 1);
}
}
static void respond_okstr(const str* s)
{
obuf_putu(&outbuf, s->len + 1);
obuf_putc(&outbuf, ':');
obuf_putc(&outbuf, 'K');
obuf_putstr(&outbuf, s);
obuf_putc(&outbuf, ',');
obuf_flush(&outbuf);
exit(0);
}
static void make_filename(const char* name)
{
if (strchr(name, '/') != 0)
respond("DUsername contains an illegal character");
if (!str_copy2s(&filename, CRONTAB_DIR "/", name))
respond("ZCould not produce filename");
}
static int fixup(int fd)
{
int pid;
int status;
int newfd;
if (fixup_argv != 0) {
if (lseek(fd, 0, SEEK_SET) != 0)
respond("ZCould not seek in temporary file");
if ((newfd = tempfile("tmp/spool")) == -1)
respond("ZCould not create temporary file");
if ((pid = fork()) == -1)
respond("ZCould not fork fixup program");
if (pid == 0) {
dup2(fd, 0);
close(fd);
dup2(newfd, 1);
close(newfd);
execvp(fixup_argv[0], fixup_argv);
die3sys(111, "Could not exec '", fixup_argv[0], "'");
}
if (waitpid(pid, &status, 0) != pid)
respond("ZWaitpid failed");
if (status != 0)
respond("ZFilter failed");
fd = newfd;
}
return fd;
}
static void cmd_store(str* data)
{
int i;
int fd;
if ((i = str_findfirst(data, 0)) <= 0)
respond("DStore command is missing data");
++i;
if ((fd = tempfile("tmp/spool")) == -1)
respond("ZCould not create temporary file");
if (write(fd, data->s + i, data->len - i) != (long)(data->len - i)
|| (fd = fixup(fd)) == -1
|| fchmod(fd, 0400) == -1
|| close(fd) != 0)
respond("ZCould not write temporary file");
if (rename(tempname.s, filename.s) != 0)
respond("ZCould not rename temporary file");
trigger_pull(TRIGGER);
respond("KCrontab successfully written");
}
static void cmd_list(void)
{
str data = {0,0,0};
if (ibuf_openreadclose(filename.s, &data) == 0) {
if (errno == ENOENT)
respond("DCrontab does not exist");
else
respond("ZCould not read crontab");
}
respond_okstr(&data);
}
static void cmd_remove(void)
{
if (unlink(filename.s) != 0 && errno != ENOENT)
respond("ZCould not remove crontab");
trigger_pull(TRIGGER);
respond("KCrontab removed");
}
static void cmd_listsys(void)
{
DIR* dir;
direntry* entry;
str data = {0,0,0};
if ((dir = opendir(CRONTAB_DIR)) == 0)
respond("ZCould not open crontabs directory");
while ((entry = readdir(dir)) != 0) {
if (entry->d_name[0] != ':')
continue;
make_filename(entry->d_name);
if (!str_cat3s(&data, "==> ", entry->d_name, " <==\n"))
respond("ZOut of memory");
if (ibuf_openreadclose(filename.s, &data) == -1)
respond("ZCould not read crontab");
if (!str_catc(&data, '\n'))
respond("ZOut of memory");
}
closedir(dir);
respond_okstr(&data);
}
static void logcmd(char cmd)
{
char cmdstr[3];
cmdstr[0] = cmd;
cmdstr[1] = ' ';
cmdstr[2] = 0;
msg2(cmdstr, username);
}
int main(int argc, char* argv[])
{
str packet = {0,0,0};
const char* s;
uid_t euid = -1;
const struct passwd* pw;
if (chdir_bcron() != 0)
respond("ZCould not change directory");
if (argc > 1)
fixup_argv = argv + 1;
if ((s = ucspi_protocol()) == 0
|| (strcmp(s, "UNIX") != 0 && strcmp(s, "LOCAL") != 0)
|| (s = ucspi_getenv("REMOTEEUID")) == 0
|| (euid = strtoul(s, (char**)&s, 0)) == (unsigned)-1
|| *s != 0)
respond("DConfiguration error: must be run from unixserver");
if (!ibuf_getnetstring(&inbuf, &packet)
|| packet.len < 2)
respond("ZInvalid input data or read error");
/* Look up and validate username */
username = packet.s + 1;
if ((pw = getpwnam(username)) == 0)
respond("DInvalid or unknown username");
if (euid != 0 && euid != pw->pw_uid)
respond("DUsername does not match invoking UID");
if (!str_copy2s(&filename, CRONTAB_DIR "/", pw->pw_name))
respond("ZCould not produce filename");
logcmd(packet.s[0]);
/* Execute the command. */
switch (packet.s[0]) {
case 'S': cmd_store(&packet); break;
case 'L': cmd_list(); break;
case 'R': cmd_remove(); break;
case 'Y':
if (euid != 0 && euid != getuid())
respond("DOnly root or cron can list system crontabs");
cmd_listsys();
break;
}
respond("DInvalid command code");
return 0;
}
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