commit dba0b8d682e77ac33fbdc6f75dee9ee9f08553f9
Hiltjo Posthuma <hiltjo@codemadness.org>
2018-12-25 20:44:18 +0100
mask signals while using connect(2) in connectto()
This makes sure connect(2) don't return a possible < 0 and errno = EINTR.
POSIX says for connect(2): "
[EINTR] The connection attempt was interrupted by a signal.
The attempt will continue asynchronously as if the
socket was non-blocking."
This was reproducable by launching with st -e sacc bitreich.org . When sacc was
signaled with SIGWINCH while it was connecting the connect(2) would be handled
as a failure and the next interface was tried. This gave a vague message "no
route to host", because the next interfaces could fail.
sacc.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/sacc.c b/sacc.c
index 7a68bb9..72e98fe 100644
--- a/sacc.c
+++ b/sacc.c
@@ -454,6 +454,7 @@ sendselector(int sock, const char *selector)
static int
connectto(const char *host, const char *port)
{
+ sigset_t set, oset;
static const struct addrinfo hints = {
.ai_family = AF_UNSPEC,
.ai_socktype = SOCK_STREAM,
@@ -462,10 +463,13 @@ connectto(const char *host, const char *port)
struct addrinfo *addrs, *addr;
int sock, r;
+ sigfillset(&set);
+ sigprocmask(SIG_BLOCK, &set, &oset);
+
if (r = getaddrinfo(host, port, &hints, &addrs)) {
diag("Can't resolve hostname \"%s\": %s",
host, gai_strerror(r));
- return -1;
+ goto err;
}
for (addr = addrs; addr; addr = addr->ai_next) {
@@ -483,15 +487,20 @@ connectto(const char *host, const char *port)
if (sock < 0) {
diag("Can't open socket: %s", strerror(errno));
- return -1;
+ goto err;
}
if (r < 0) {
diag("Can't connect to: %s:%s: %s",
host, port, strerror(errno));
- return -1;
+ goto err;
}
+ sigprocmask(SIG_SETMASK, &oset, NULL);
return sock;
+
+err:
+ sigprocmask(SIG_SETMASK, &oset, NULL);
+ return -1;
}
static int