fd: Improve error handling of write_nonblock().
[paraslash.git] / dccp_send.c
index 7d8967c..fa2a163 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2012 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -13,7 +13,6 @@
 
 #include <regex.h>
 #include <sys/types.h>
-#include <dirent.h>
 #include <osl.h>
 
 #include "para.h"
 #include "server.h"
 #include "net.h"
 #include "list.h"
-#include "vss.h"
 #include "send.h"
+#include "sched.h"
+#include "vss.h"
 #include "fd.h"
 #include "close_on_fork.h"
 #include "chunk_queue.h"
 #include "server.cmdline.h"
 #include "acl.h"
 
-/** Do not write more than that many bytes at once. */
-#define DCCP_MAX_BYTES_PER_WRITE 1024
-
 static struct sender_status dccp_sender_status, *dss = &dccp_sender_status;
 
+struct dccp_fec_client {
+       struct fec_client_parms fcp;
+       struct fec_client *fc;
+};
+
 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
                __a_unused fd_set *wfds)
 {
@@ -65,14 +67,56 @@ static int dccp_get_tx_ccid(int sockfd)
        return tx_ccid;
 }
 
+static void dccp_shutdown_client(struct sender_client *sc)
+{
+       struct dccp_fec_client *dfc = sc->private_data;
+
+       vss_del_fec_client(dfc->fc);
+       shutdown_client(sc, dss);
+}
+
+static void dccp_shutdown_clients(void)
+{
+       struct sender_client *sc, *tmp;
+
+       list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
+               dccp_shutdown_client(sc);
+}
+
+/** * Obtain current MPS according to RFC 4340, sec. 14. */
+static int dccp_init_fec(struct sender_client *sc)
+{
+       int mps, ret;
+       socklen_t ml = sizeof(mps);
+
+       /* If call fails, return some sensible minimum value */
+       ret = getsockopt(sc->fd, SOL_DCCP, DCCP_SOCKOPT_GET_CUR_MPS, &mps, &ml);
+       if (ret < 0) {
+               PARA_NOTICE_LOG("can not determine MPS: %s\n", strerror(errno));
+               mps = generic_max_transport_msg_size(sc->fd) - DCCP_MAX_HEADER;
+       }
+       PARA_INFO_LOG("current MPS = %d bytes\n", mps);
+       assert(mps > 0);
+       if (conf.dccp_max_slice_size_arg > 0)
+               mps = PARA_MIN(mps, conf.dccp_max_slice_size_arg);
+       return mps;
+}
+
+static void dccp_send_fec(struct sender_client *sc, char *buf, size_t len)
+{
+       int ret = write_nonblock(sc->fd, buf, len);
+
+       if (ret < 0)
+               dccp_shutdown_client(sc);
+}
+
 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
 {
        struct sender_client *sc;
+       struct dccp_fec_client *dfc;
        int tx_ccid;
 
-       if (dss->listen_fd < 0 || !FD_ISSET(dss->listen_fd, rfds))
-               return;
-       sc = accept_sender_client(dss);
+       sc = accept_sender_client(dss, rfds);
        if (!sc)
                return;
 
@@ -89,26 +133,19 @@ static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
         * from the client; by shutting down this unused communication path we can
         * reduce processing costs a bit. See analogous comment in dccp_recv.c.
         */
-       if (shutdown(sc->fd, SHUT_RD) >= 0)
+       if (shutdown(sc->fd, SHUT_RD) < 0) {
+               PARA_WARNING_LOG("%s\n", strerror(errno));
+               shutdown_client(sc, dss);
                return;
-       PARA_WARNING_LOG("%s\n", strerror(errno));
-       shutdown_client(sc, dss);
-}
-
-static void dccp_send(long unsigned current_chunk,
-               __a_unused long unsigned chunks_sent, const char *buf,
-               size_t len, const char *header_buf, size_t header_len)
-{
-       struct sender_client *sc, *tmp;
-
-       list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
-               send_chunk(sc, dss, DCCP_MAX_BYTES_PER_WRITE, current_chunk, buf,
-                       len, header_buf, header_len);
-}
-
-static void dccp_shutdown_clients(void)
-{
-       shutdown_clients(dss);
+       }
+       dfc = para_calloc(sizeof(*dfc));
+       sc->private_data = dfc;
+       dfc->fcp.data_slices_per_group  = conf.dccp_data_slices_per_group_arg;
+       dfc->fcp.slices_per_group       = conf.dccp_slices_per_group_arg;
+       dfc->fcp.init_fec               = dccp_init_fec;
+       dfc->fcp.send_fec               = dccp_send_fec;
+       dfc->fcp.need_periodic_header   = false;
+       dfc->fc = vss_add_fec_client(sc, &dfc->fcp);
 }
 
 static int dccp_com_on(__a_unused struct sender_command_data *scd)
@@ -118,6 +155,7 @@ static int dccp_com_on(__a_unused struct sender_command_data *scd)
 
 static int dccp_com_off(__a_unused struct sender_command_data *scd)
 {
+       dccp_shutdown_clients();
        generic_com_off(dss);
        return 1;
 }
@@ -140,12 +178,13 @@ static int dccp_com_allow(struct sender_command_data *scd)
  */
 static const char *dccp_list_available_ccids(void)
 {
-       uint8_t ccids[DCCP_MAX_HOST_CCIDS];
-       uint8_t nccids = sizeof(ccids), i, len;
        /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
        static char list[DCCP_MAX_HOST_CCIDS * 4];
+       uint8_t *ccids;
+       int i, len, nccids;
 
-       if (dccp_available_ccids(ccids, &nccids) == NULL) {
+       nccids = dccp_available_ccids(&ccids);
+       if (nccids < 0) {
                snprintf(list, sizeof(list), "Unable to query available CCIDs");
        } else {
                for (i = len = 0; i < nccids; i++)
@@ -174,13 +213,14 @@ static char *dccp_info(void)
  */
 void dccp_send_init(struct sender *s)
 {
-       int ret;
+       int ret, k, n;
 
        s->info = dccp_info;
-       s->send = dccp_send;
+       s->send = NULL;
        s->pre_select = dccp_pre_select;
        s->post_select = dccp_post_select;
        s->shutdown_clients = dccp_shutdown_clients;
+       s->resolve_target = NULL;
        s->help = generic_sender_help;
        s->client_cmds[SENDER_ON] = dccp_com_on;
        s->client_cmds[SENDER_OFF] = dccp_com_off;
@@ -189,6 +229,15 @@ void dccp_send_init(struct sender *s)
        s->client_cmds[SENDER_ADD] = NULL;
        s->client_cmds[SENDER_DELETE] = NULL;
 
+       k = conf.dccp_data_slices_per_group_arg;
+       n = conf.dccp_slices_per_group_arg;
+
+       if (k <= 0 || n <= 0 || k >= n) {
+               PARA_WARNING_LOG("invalid FEC parameters, using defaults\n");
+               conf.dccp_data_slices_per_group_arg = 3;
+               conf.dccp_slices_per_group_arg = 4;
+       }
+
        init_sender_status(dss, conf.dccp_access_arg, conf.dccp_access_given,
                conf.dccp_port_arg, conf.dccp_max_clients_arg,
                conf.dccp_default_deny_given);