/* Run command CMD and return statistics on it.
Put the statistics in *RESP. */
static void run_command(char *const *cmd, resource_t *resp)
{
pid_t pid; /* Pid of child. */
void (*interrupt_signal)(int);
void (*quit_signal)(int);
resp->elapsed_ms = monotonic_ms();
pid = vfork(); /* Run CMD as child process. */
if (pid < 0)
bb_perror_msg_and_die("fork");
if (pid == 0) { /* If child. */
/* Don't cast execvp arguments; that causes errors on some systems,
versus merely warnings if the cast is left off. */
BB_EXECVP(cmd[0], cmd);
xfunc_error_retval = (errno == ENOENT ? 127 : 126);
bb_error_msg_and_die("can't run %s", cmd[0]);
}
/* Have signals kill the child but not self (if possible). */
//TODO: just block all sigs? and reenable them in the very end in main?
interrupt_signal = signal(SIGINT, SIG_IGN);
quit_signal = signal(SIGQUIT, SIG_IGN);
resuse_end(pid, resp);
/* Re-enable signals. */
signal(SIGINT, interrupt_signal);
signal(SIGQUIT, quit_signal);
}
/*
* Check expiration for each timer. If a timer is expired,
* call the expire function for the timer and update the timer.
* Return the next interval for select() call.
*/
struct timeval *dhcp6_timer_check(void)
{
unsigned long long now = monotonic_ms();
struct dhcp6_timer *tm, *tm_next;
client6_config.tm_sentinel = ULLONG_MAX;
for (tm = LIST_FIRST(&client6_config.timer_head); tm; tm = tm_next) {
tm_next = LIST_NEXT(tm, link);
if ((long long)(now - tm->t) >= 0) {
if ((*tm->expire)(tm->expire_data) == NULL)
continue; /* timer has been freed */
}
if (tm->t < client6_config.tm_sentinel)
client6_config.tm_sentinel = tm->t;
}
if (ULLONG_MAX == client6_config.tm_sentinel) {
/* no need to timeout */
return NULL;
} else if (client6_config.tm_sentinel < now) {
/* this may occur when the interval is too small */
client6_config.tm_check.tv_sec = client6_config.tm_check.tv_usec = 0;
} else {
client6_config.tm_check.tv_sec =
(client6_config.tm_sentinel - now) / 1000ULL;
client6_config.tm_check.tv_usec =
((client6_config.tm_sentinel - now) % 1000ULL) * 1000ULL;
}
return (&client6_config.tm_check);
}
void dhcp6_timer_set(unsigned long long t, struct dhcp6_timer *timer)
{
timer->t = monotonic_ms() + t;
/* update the next expiration time */
if (timer->t < client6_config.tm_sentinel)
client6_config.tm_sentinel = timer->t;
}
unsigned long long dhcp6_timer_rest(struct dhcp6_timer *timer)
{
unsigned long long now = monotonic_ms();
if (timer->t - now <= 0) {
log2("a timer must be expired, but not yet");
return 0;
} else {
return (timer->t - now);
}
}
/* pid_t is short on BSDI, so don't try to promote it. */
static void resuse_end(pid_t pid, resource_t *resp)
{
pid_t caught;
/* Ignore signals, but don't ignore the children. When wait3
returns the child process, set the time the command finished. */
while ((caught = wait3(&resp->waitstatus, 0, &resp->ru)) != pid) {
if (caught == -1 && errno != EINTR) {
bb_perror_msg("wait");
return;
}
}
resp->elapsed_ms = monotonic_ms() - resp->elapsed_ms;
}
/* Run command CMD and return statistics on it.
Put the statistics in *RESP. */
static void run_command(char *const *cmd, resource_t *resp)
{
pid_t pid;
void (*interrupt_signal)(int);
void (*quit_signal)(int);
resp->elapsed_ms = monotonic_ms();
pid = xvfork();
if (pid == 0) {
/* Child */
BB_EXECVP_or_die((char**)cmd);
}
/* Have signals kill the child but not self (if possible). */
//TODO: just block all sigs? and reenable them in the very end in main?
interrupt_signal = signal(SIGINT, SIG_IGN);
quit_signal = signal(SIGQUIT, SIG_IGN);
resuse_end(pid, resp);
/* Re-enable signals. */
signal(SIGINT, interrupt_signal);
signal(SIGQUIT, quit_signal);
}
//TODO: use more efficient setvar() which takes a pointer to malloced "VAR=VAL"
//string. hush naturally has it, and ash has setvareq().
//Here we can simply store "VAR=" at buffer start and store read data directly
//after "=", then pass buffer to setvar() to consume.
const char* FAST_FUNC
shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
char **argv,
const char *ifs,
int read_flags,
const char *opt_n,
const char *opt_p,
const char *opt_t,
const char *opt_u
)
{
unsigned end_ms; /* -t TIMEOUT */
int fd; /* -u FD */
int nchars; /* -n NUM */
char **pp;
char *buffer;
struct termios tty, old_tty;
const char *retval;
int bufpos; /* need to be able to hold -1 */
int startword;
smallint backslash;
pp = argv;
while (*pp) {
if (!is_well_formed_var_name(*pp, '\0')) {
/* Mimic bash message */
bb_error_msg("read: '%s': not a valid identifier", *pp);
return (const char *)(uintptr_t)1;
}
pp++;
}
nchars = 0; /* if != 0, -n is in effect */
if (opt_n) {
nchars = bb_strtou(opt_n, NULL, 10);
if (nchars < 0 || errno)
return "invalid count";
/* note: "-n 0": off (bash 3.2 does this too) */
}
end_ms = 0;
if (opt_t) {
end_ms = bb_strtou(opt_t, NULL, 10);
if (errno || end_ms > UINT_MAX / 2048)
return "invalid timeout";
end_ms *= 1000;
#if 0 /* even bash has no -t N.NNN support */
ts.tv_sec = bb_strtou(opt_t, &p, 10);
ts.tv_usec = 0;
/* EINVAL means number is ok, but not terminated by NUL */
if (*p == '.' && errno == EINVAL) {
char *p2;
if (*++p) {
int scale;
ts.tv_usec = bb_strtou(p, &p2, 10);
if (errno)
return "invalid timeout";
scale = p2 - p;
/* normalize to usec */
if (scale > 6)
return "invalid timeout";
while (scale++ < 6)
ts.tv_usec *= 10;
}
} else if (ts.tv_sec < 0 || errno) {
return "invalid timeout";
}
if (!(ts.tv_sec | ts.tv_usec)) { /* both are 0? */
return "invalid timeout";
}
#endif /* if 0 */
}
fd = STDIN_FILENO;
if (opt_u) {
fd = bb_strtou(opt_u, NULL, 10);
if (fd < 0 || errno)
return "invalid file descriptor";
}
if (opt_p && isatty(fd)) {
fputs(opt_p, stderr);
fflush_all();
}
if (ifs == NULL)
ifs = defifs;
if (nchars || (read_flags & BUILTIN_READ_SILENT)) {
tcgetattr(fd, &tty);
old_tty = tty;
if (nchars) {
tty.c_lflag &= ~ICANON;
tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
}
if (read_flags & BUILTIN_READ_SILENT) {
tty.c_lflag &= ~(ECHO | ECHOK | ECHONL);
}
/* This forces execution of "restoring" tcgetattr later */
read_flags |= BUILTIN_READ_SILENT;
/* if tcgetattr failed, tcsetattr will fail too.
* Ignoring, it's harmless. */
tcsetattr(fd, TCSANOW, &tty);
}
retval = (const char *)(uintptr_t)0;
startword = 1;
backslash = 0;
if (end_ms) /* NB: end_ms stays nonzero: */
end_ms = ((unsigned)monotonic_ms() + end_ms) | 1;
buffer = NULL;
bufpos = 0;
do {
char c;
if (end_ms) {
int timeout;
struct pollfd pfd[1];
pfd[0].fd = fd;
pfd[0].events = POLLIN;
timeout = end_ms - (unsigned)monotonic_ms();
if (timeout <= 0 /* already late? */
|| safe_poll(pfd, 1, timeout) != 1 /* no? wait... */
) { /* timed out! */
retval = (const char *)(uintptr_t)1;
goto ret;
}
}
if ((bufpos & 0xff) == 0)
buffer = xrealloc(buffer, bufpos + 0x100);
if (nonblock_safe_read(fd, &buffer[bufpos], 1) != 1) {
retval = (const char *)(uintptr_t)1;
break;
}
c = buffer[bufpos];
if (c == '\0')
continue;
if (backslash) {
backslash = 0;
if (c != '\n')
goto put;
continue;
}
if (!(read_flags & BUILTIN_READ_RAW) && c == '\\') {
backslash = 1;
continue;
}
if (c == '\n')
break;
/* $IFS splitting. NOT done if we run "read"
* without variable names (bash compat).
* Thus, "read" and "read REPLY" are not the same.
*/
if (argv[0]) {
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 */
const char *is_ifs = strchr(ifs, c);
if (startword && is_ifs) {
if (isspace(c))
continue;
/* it is a non-space ifs char */
startword--;
if (startword == 1) /* first one? */
continue; /* yes, it is not next word yet */
}
startword = 0;
if (argv[1] != NULL && is_ifs) {
buffer[bufpos] = '\0';
bufpos = 0;
setvar(*argv, buffer);
argv++;
/* can we skip one non-space ifs char? (2: yes) */
startword = isspace(c) ? 2 : 1;
continue;
}
}
put:
bufpos++;
} while (--nchars);
if (argv[0]) {
/* Remove trailing space $IFS chars */
while (--bufpos >= 0 && isspace(buffer[bufpos]) && strchr(ifs, buffer[bufpos]) != NULL)
continue;
buffer[bufpos + 1] = '\0';
/* Use the remainder as a value for the next variable */
setvar(*argv, buffer);
/* Set the rest to "" */
while (*++argv)
setvar(*argv, "");
} else {
/* Note: no $IFS removal */
buffer[bufpos] = '\0';
setvar("REPLY", buffer);
}
ret:
free(buffer);
if (read_flags & BUILTIN_READ_SILENT)
tcsetattr(fd, TCSANOW, &old_tty);
return retval;
}
/* Returns 1 if no reply received */
int FAST_FUNC arpping(uint32_t test_nip,
const uint8_t *safe_mac,
uint32_t from_ip,
uint8_t *from_mac,
const char *interface,
unsigned timeo)
{
int timeout_ms;
struct pollfd pfd[1];
#define s (pfd[0].fd) /* socket */
int rv = 1; /* "no reply received" yet */
struct sockaddr addr; /* for interface name */
struct arpMsg arp;
if (!timeo)
return 1;
s = socket(PF_PACKET, SOCK_PACKET, htons(ETH_P_ARP));
if (s == -1) {
bb_perror_msg(bb_msg_can_not_create_raw_socket);
return -1;
}
if (setsockopt_broadcast(s) == -1) {
bb_perror_msg("can't enable bcast on raw socket");
goto ret;
}
/* send arp request */
memset(&arp, 0, sizeof(arp));
memset(arp.h_dest, 0xff, 6); /* MAC DA */
memcpy(arp.h_source, from_mac, 6); /* MAC SA */
arp.h_proto = htons(ETH_P_ARP); /* protocol type (Ethernet) */
arp.htype = htons(ARPHRD_ETHER); /* hardware type */
arp.ptype = htons(ETH_P_IP); /* protocol type (ARP message) */
arp.hlen = 6; /* hardware address length */
arp.plen = 4; /* protocol address length */
arp.operation = htons(ARPOP_REQUEST); /* ARP op code */
memcpy(arp.sHaddr, from_mac, 6); /* source hardware address */
memcpy(arp.sInaddr, &from_ip, sizeof(from_ip)); /* source IP address */
/* tHaddr is zero-filled */ /* target hardware address */
memcpy(arp.tInaddr, &test_nip, sizeof(test_nip));/* target IP address */
memset(&addr, 0, sizeof(addr));
safe_strncpy(addr.sa_data, interface, sizeof(addr.sa_data));
if (sendto(s, &arp, sizeof(arp), 0, &addr, sizeof(addr)) < 0) {
// TODO: error message? caller didn't expect us to fail,
// just returning 1 "no reply received" misleads it.
goto ret;
}
/* wait for arp reply, and check it */
timeout_ms = (int)timeo;
do {
typedef uint32_t aliased_uint32_t FIX_ALIASING;
int r;
unsigned prevTime = monotonic_ms();
pfd[0].events = POLLIN;
r = safe_poll(pfd, 1, timeout_ms);
if (r < 0)
break;
if (r) {
r = safe_read(s, &arp, sizeof(arp));
if (r < 0)
break;
//log3("sHaddr %02x:%02x:%02x:%02x:%02x:%02x",
// arp.sHaddr[0], arp.sHaddr[1], arp.sHaddr[2],
// arp.sHaddr[3], arp.sHaddr[4], arp.sHaddr[5]);
if (r >= ARP_MSG_SIZE
&& arp.operation == htons(ARPOP_REPLY)
/* don't check it: Linux doesn't return proper tHaddr (fixed in 2.6.24?) */
/* && memcmp(arp.tHaddr, from_mac, 6) == 0 */
&& *(aliased_uint32_t*)arp.sInaddr == test_nip
) {
/* if ARP source MAC matches safe_mac
* (which is client's MAC), then it's not a conflict
* (client simply already has this IP and replies to ARPs!)
*/
if (!safe_mac || memcmp(safe_mac, arp.sHaddr, 6) != 0)
rv = 0;
//else log2("sHaddr == safe_mac");
break;
}
}
timeout_ms -= (unsigned)monotonic_ms() - prevTime + 1;
/* We used to check "timeout_ms > 0", but
* this is more under/overflow-resistant
* (people did see overflows here when system time jumps):
*/
} while ((unsigned)timeout_ms <= timeo);
ret:
close(s);
log1("%srp reply received for this address", rv ? "no a" : "A");
return rv;
}
