#include <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 <iobuf/iobuf.h>

#include <misc/ucspi.h>

#include <msg/msg.h>

#include <path/path.h>

#include <str/str.h>

#include <unix/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;

}