diff options
Diffstat (limited to 'networking/udhcp/signalpipe.c')
| -rw-r--r-- | networking/udhcp/signalpipe.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/networking/udhcp/signalpipe.c b/networking/udhcp/signalpipe.c index 2ff78f0f2..81d1fc01a 100644 --- a/networking/udhcp/signalpipe.c +++ b/networking/udhcp/signalpipe.c @@ -20,14 +20,14 @@ */ #include "common.h" -/* Global variable: we access it from signal handler */ -static struct fd_pair signal_pipe; +#define READ_FD 3 +#define WRITE_FD 4 static void signal_handler(int sig) { int sv = errno; unsigned char ch = sig; /* use char, avoid dealing with partial writes */ - if (write(signal_pipe.wr, &ch, 1) != 1) + if (write(WRITE_FD, &ch, 1) != 1) bb_perror_msg("can't send signal"); errno = sv; } @@ -36,12 +36,25 @@ static void signal_handler(int sig) * and installs the signal handler */ void FAST_FUNC udhcp_sp_setup(void) { + struct fd_pair signal_pipe; + + /* All callers also want this, so... */ + bb_sanitize_stdio(); + /* was socketpair, but it needs AF_UNIX in kernel */ xpiped_pair(signal_pipe); - close_on_exec_on(signal_pipe.rd); - close_on_exec_on(signal_pipe.wr); - ndelay_on(signal_pipe.rd); - ndelay_on(signal_pipe.wr); + + /* usually we get fds 3 and 4, but if we get higher ones... */ + if (signal_pipe.rd != READ_FD) + xmove_fd(signal_pipe.rd, READ_FD); + if (signal_pipe.wr != WRITE_FD) + xmove_fd(signal_pipe.wr, WRITE_FD); + + close_on_exec_on(READ_FD); + close_on_exec_on(WRITE_FD); + ndelay_on(READ_FD); + ndelay_on(WRITE_FD); + bb_signals(0 + (1 << SIGUSR1) + (1 << SIGUSR2) @@ -54,7 +67,7 @@ void FAST_FUNC udhcp_sp_setup(void) */ void FAST_FUNC udhcp_sp_fd_set(struct pollfd pfds[2], int extra_fd) { - pfds[0].fd = signal_pipe.rd; + pfds[0].fd = READ_FD; pfds[0].events = POLLIN; pfds[1].fd = -1; if (extra_fd >= 0) { @@ -74,7 +87,7 @@ int FAST_FUNC udhcp_sp_read(void) unsigned char sig; /* Can't block here, fd is in nonblocking mode */ - if (safe_read(signal_pipe.rd, &sig, 1) != 1) + if (safe_read(READ_FD, &sig, 1) != 1) return 0; return sig; |