Segmentize outgoing packets.

diff --git a/selftest.c b/selftest.c
index dae05bf37b9d6809451cd5b761e0cd67fa84eca2..6edbc0d4ecf2016a5f2b050b9dd0b2ba0a4cac79 100644 (file)
--- a/selftest.c
+++ b/selftest.c
@@ -56,7 +56,6 @@ int do_send(struct utcp *utcp, void *data, size_t len) {
                return utcp_recv(a, data, len);
 }
 
-
 int main(int argc, char *argv[]) {
        srand(time(NULL));
 
@@ -82,8 +81,23 @@ int main(int argc, char *argv[]) {
        fprintf(stderr, "\nTesting connection with data transfer\n\n");
 
        c = utcp_connect(b, 7, do_recv, NULL);
-       utcp_send(c, "Hello world!\n", 13);
-       utcp_send(c, "This is a test.\n", 16);
+       ssize_t len = utcp_send(c, "Hello world!\n", 13);
+
+       if(len != 13) {
+               if(len < 0)
+                       fprintf(stderr, "Error: %s\n", strerror(errno));
+               else
+                       fprintf(stderr, "Short write %zd!\n", len);
+       }
+       len = utcp_send(c, "This is a test.\n", 16);
+
+       if(len != 16) {
+               if(len < 0)
+                       fprintf(stderr, "Error: %s\n", strerror(errno));
+               else
+                       fprintf(stderr, "Short write %zd!\n", len);
+       }
+
        fprintf(stderr, "closing...\n");
        utcp_close(c);
 

diff --git a/utcp.c b/utcp.c
index 7db7b5e043ed450251d532c8ccbcf4f4d9dbe06e..91aee3ce090f257e2d562b520e3ae59239012f33 100644 (file)
--- a/utcp.c
+++ b/utcp.c
@@ -210,7 +210,7 @@ static void free_connection(struct utcp_connection *c) {
 
 static struct utcp_connection *allocate_connection(struct utcp *utcp, uint16_t src, uint16_t dst) {
        // Check whether this combination of src and dst is free
-       
+
        if(src) {
                if(find_connection(utcp, src, dst)) {
                        errno = EADDRINUSE;
@@ -256,6 +256,10 @@ static struct utcp_connection *allocate_connection(struct utcp *utcp, uint16_t s
        c->snd.nxt = c->snd.iss + 1;
        c->rcv.wnd = utcp->mtu;
        c->utcp = utcp;
+       c->sndbufsize = 65536;
+       c->sndbuf = malloc(c->sndbufsize);
+       if(!c->sndbuf)
+               c->sndbufsize = 0;
 
        // Add it to the sorted list of connections
 
@@ -302,7 +306,7 @@ void utcp_accept(struct utcp_connection *c, utcp_recv_t recv, void *priv) {
        set_state(c, ESTABLISHED);
 }
 
-int utcp_send(struct utcp_connection *c, void *data, size_t len) {
+ssize_t utcp_send(struct utcp_connection *c, void *data, size_t len) {
        if(c->reapable) {
                fprintf(stderr, "Error: send() called on closed connection %p\n", c);
                errno = EBADF;
@@ -330,6 +334,8 @@ int utcp_send(struct utcp_connection *c, void *data, size_t len) {
                return -1;
        }
 
+       // Add data to send buffer
+
        if(!len)
                return 0;
 
@@ -338,30 +344,43 @@ int utcp_send(struct utcp_connection *c, void *data, size_t len) {
                return -1;
        }
 
-       
+       uint32_t bufused = c->snd.nxt - c->snd.una;
+
+       if(len > c->sndbufsize - bufused)
+               len = c->sndbufsize - bufused;
+
+       memcpy(c->sndbuf + (c->snd.nxt - c->snd.una), data, len);
+
+       // Send segments
+
        struct {
                struct hdr hdr;
-               char data[len];
+               char data[c->utcp->mtu];
        } pkt;
 
        pkt.hdr.src = c->src;
        pkt.hdr.dst = c->dst;
-       pkt.hdr.seq = c->snd.nxt;
        pkt.hdr.ack = c->rcv.nxt;
        pkt.hdr.wnd = c->snd.wnd;
        pkt.hdr.ctl = ACK;
 
-       memcpy(pkt.data, data, len);
+       uint32_t left = len;
 
-       c->snd.nxt += len;
+       while(left) {
+               uint32_t seglen = left > c->utcp->mtu ? c->utcp->mtu : left;
+               pkt.hdr.seq = c->snd.nxt;
 
-       c->utcp->send(c->utcp, &pkt, sizeof pkt.hdr + len);
-       //
-       // Can we add it to the send window?
-       
-       // Do we need to kick some timers?
-       
-       return 0;
+               memcpy(pkt.data, data, seglen);
+
+               c->snd.nxt += seglen;
+               data += seglen;
+               left -= seglen;
+
+               c->utcp->send(c->utcp, &pkt, sizeof pkt.hdr + seglen);
+       }
+
+       fprintf(stderr, "len=%u\n", len);
+       return len;
 }
 
 static void swap_ports(struct hdr *hdr) {
@@ -445,7 +464,7 @@ int utcp_recv(struct utcp *utcp, void *data, size_t len) {
        }
 
        // It is for an existing connection.
-       
+
        if(c->state == SYN_SENT) {
                if(hdr.ctl & ACK) {
                        if(seqdiff(hdr.ack, c->snd.iss) <= 0 || seqdiff(hdr.ack, c->snd.nxt) > 0) {
@@ -514,7 +533,7 @@ int utcp_recv(struct utcp *utcp, void *data, size_t len) {
        c->snd.wnd = hdr.wnd;
 
        // TODO: check whether segment really starts at rcv.nxt, otherwise trim it.
-       
+
        if(hdr.ctl & RST) {
                switch(c->state) {
                case SYN_RECEIVED:
@@ -659,7 +678,7 @@ int utcp_recv(struct utcp *utcp, void *data, size_t len) {
        }
 
        // Process the data
-       
+
        if(len && c->recv) {
                c->recv(c, data, len);
                c->rcv.nxt += len;

diff --git a/utcp.h b/utcp.h
index 45cb6f32a9a0a507fcf860cc16f816c7a5a822fe..5729ef228add16126f9bf2b8e102a62b91902b46 100644 (file)
--- a/utcp.h
+++ b/utcp.h
@@ -48,7 +48,7 @@ extern struct utcp *utcp_init(utcp_accept_t accept, utcp_pre_accept_t pre_accept
 extern void utcp_exit(struct utcp *utcp);
 extern struct utcp_connection *utcp_connect(struct utcp *utcp, uint16_t port, utcp_recv_t recv, void *priv);
 extern void utcp_accept(struct utcp_connection *utcp, utcp_recv_t recv, void *priv);
-extern int utcp_send(struct utcp_connection *connection, void *data, size_t len);
+extern ssize_t utcp_send(struct utcp_connection *connection, void *data, size_t len);
 extern int utcp_recv(struct utcp *utcp, void *data, size_t len);
 extern int utcp_close(struct utcp_connection *connection);
 extern int utcp_abort(struct utcp_connection *connection);