: sizeof(struct sockaddr_in);
}
+/** True if @ss holds a v6-mapped-v4 address (RFC 4291, 2.5.5.2) */
+static bool SS_IS_ADDR_V4MAPPED(const struct sockaddr_storage *ss)
+{
+ const struct sockaddr_in6 *ia6 = (const struct sockaddr_in6 *)ss;
+
+ return ss->ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&ia6->sin6_addr);
+}
+
/**
* Process IPv4/v6 address, turn v6-mapped-v4 address into normal IPv4 address.
* \param ss Container of IPv4/6 address.
static const struct sockaddr *
normalize_ip_address(const struct sockaddr_storage *ss)
{
- const struct sockaddr_in6 *ia6 = (const struct sockaddr_in6 *)ss;
-
assert(ss->ss_family == AF_INET || ss->ss_family == AF_INET6);
- if (ss->ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&ia6->sin6_addr)) {
+ if (SS_IS_ADDR_V4MAPPED(ss)) {
+ const struct sockaddr_in6 *ia6 = (const struct sockaddr_in6 *)ss;
static struct sockaddr_in ia;
ia.sin_family = AF_INET;
return (const struct sockaddr *)ss;
}
+/**
+ * Generic/fallback MTU values
+ *
+ * These are taken from RFC 1122, RFC 2460, and RFC 5405.
+ * - RFC 1122, 3.3.3 defines EMTU_S ("Effective MTU for sending") and recommends
+ * to use an EMTU_S size of of 576 bytes if the IPv4 path MTU is unknown;
+ * - RFC 2460, 5. requires a minimum IPv6 MTU of 1280 bytes;
+ * - RFC 5405, 3.2 recommends that if path MTU discovery is not done,
+ * UDP senders should use the respective minimum values of EMTU_S.
+ */
+static inline int generic_mtu(const int af_type)
+{
+ return af_type == AF_INET6 ? 1280 : 576;
+}
+
+/** Crude approximation of IP header overhead - neglecting options. */
+static inline int estimated_header_overhead(const int af_type)
+{
+ return af_type == AF_INET6 ? 40 : 20;
+}
+
+/**
+ * Maximum transport-layer message size (MMS_S) as per RFC 1122, 3.3.3
+ * Socket must be connected.
+ */
+int generic_max_transport_msg_size(int sockfd)
+{
+ struct sockaddr_storage ss;
+ socklen_t sslen = sizeof(ss);
+ int af_type = AF_INET;
+
+ if (getpeername(sockfd, (struct sockaddr *)&ss, &sslen) < 0) {
+ PARA_ERROR_LOG("can not determine remote address type: %s\n",
+ strerror(errno));
+ } else if (!SS_IS_ADDR_V4MAPPED(&ss)) {
+ af_type = ss.ss_family;
+ }
+ return generic_mtu(af_type) - estimated_header_overhead(af_type);
+}
+
/**
* Print numeric host and port number (beware - uses static char).
*
* \param sa The IPv4/IPv6 socket address to use.
*
+ * \return Host string in numeric host:port format, \sa parse_url().
* \sa getnameinfo(3), services(5), nsswitch.conf(5)
*/
static char *host_and_port(const struct sockaddr_storage *ss)
{
const struct sockaddr *sa = normalize_ip_address(ss);
char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
- static char output[sizeof(hbuf) + sizeof(sbuf) + 2];
+ static char output[sizeof(hbuf) + sizeof(sbuf) + 4];
int ret;
ret = getnameinfo(sa, salen(sa),
hbuf, sizeof(hbuf),
sbuf, sizeof(sbuf),
- NI_NUMERICHOST);
- if (ret == 0) {
- snprintf(output, sizeof(output), "%s#%s", hbuf, sbuf);
- } else {
+ NI_NUMERICHOST | NI_NUMERICSERV);
+ if (ret) {
snprintf(output, sizeof(output), "(unknown)");
PARA_WARNING_LOG("hostname lookup error (%s).\n",
gai_strerror(ret));
+ } else if (sa->sa_family == AF_INET6) {
+ snprintf(output, sizeof(output), "[%s]:%s", hbuf, sbuf);
+ } else {
+ snprintf(output, sizeof(output), "%s:%s", hbuf, sbuf);
}
return output;
}
* Wrapper around the accept system call.
*
* \param fd The listening socket.
+ * \param rfds An optional fd_set pointer.
* \param addr Structure which is filled in with the address of the peer socket.
* \param size Should contain the size of the structure pointed to by \a addr.
+ * \param new_fd Result pointer.
*
- * Accept incoming connections on \a addr. Retry if interrupted.
+ * Accept incoming connections on \a addr, retry if interrupted. If \a rfds is
+ * not \p NULL, return 0 if \a fd is not set in \a rfds without calling accept().
*
- * \return The new file descriptor on success, negative on errors.
+ * \return Negative on errors, zero if no connections are present to be accepted,
+ * one otherwise.
*
* \sa accept(2).
*/
-int para_accept(int fd, void *addr, socklen_t size)
+int para_accept(int fd, fd_set *rfds, void *addr, socklen_t size, int *new_fd)
{
- int new_fd;
+ int ret;
+ if (rfds && !FD_ISSET(fd, rfds))
+ return 0;
do
- new_fd = accept(fd, (struct sockaddr *) addr, &size);
- while (new_fd < 0 && errno == EINTR);
- return new_fd < 0? -ERRNO_TO_PARA_ERROR(errno) : new_fd;
+ ret = accept(fd, (struct sockaddr *) addr, &size);
+ while (ret < 0 && errno == EINTR);
+
+ if (ret >= 0) {
+ *new_fd = ret;
+ return 1;
+ }
+ if (errno == EAGAIN || errno == EWOULDBLOCK)
+ return 0;
+ return -ERRNO_TO_PARA_ERROR(errno);
}
/**
return result;
}
#endif /* HAVE_UCRED */
-
-/**
- * Receive a buffer and check for a pattern.
- *
- * \param fd The file descriptor to receive from.
- * \param pattern The expected pattern.
- * \param bufsize The size of the internal buffer.
- *
- * \return Positive if \a pattern was received, negative otherwise.
- *
- * This function tries to receive at most \a bufsize bytes from file descriptor
- * \a fd. If at least \p strlen(\a pattern) bytes were received, the beginning
- * of the received buffer is compared with \a pattern, ignoring case.
- *
- * \sa recv_buffer(), \sa strncasecmp(3).
- */
-int recv_pattern(int fd, const char *pattern, size_t bufsize)
-{
- size_t len = strlen(pattern);
- char *buf = para_malloc(bufsize + 1);
- int ret = -E_RECV_PATTERN, n = recv_buffer(fd, buf, bufsize + 1);
-
- if (n < len)
- goto out;
- if (strncasecmp(buf, pattern, len))
- goto out;
- ret = 1;
-out:
- if (ret < 0) {
- PARA_NOTICE_LOG("did not receive pattern '%s'\n", pattern);
- if (n > 0)
- PARA_NOTICE_LOG("recvd %d bytes: %s\n", n, buf);
- else if (n < 0)
- PARA_NOTICE_LOG("%s\n", para_strerror(-n));
- }
- free(buf);
- return ret;
-}