#include <sys/time.h>
#include <sys/socket.h>
-#define UTCP_INTERNAL
-#include "utcp.h"
-
-#define PREP(l) char pkt[(l) + sizeof struct hdr]; struct hdr *hdr = &pkt;
-
-#define SYN 1
-#define ACK 2
-#define FIN 4
-#define RST 8
-
-struct hdr {
- uint16_t src; // Source port
- uint16_t dst; // Destination port
- uint32_t seq; // Sequence number
- uint32_t ack; // Acknowledgement number
- uint32_t wnd; // Window size
- uint16_t ctl; // Flags (SYN, ACK, FIN, RST)
- uint16_t aux; // other stuff
-};
-
-enum state {
- CLOSED,
- LISTEN,
- SYN_SENT,
- SYN_RECEIVED,
- ESTABLISHED,
- FIN_WAIT_1,
- FIN_WAIT_2,
- CLOSE_WAIT,
- CLOSING,
- LAST_ACK,
- TIME_WAIT
-};
-
-const char *strstate[] = {
- "CLOSED",
- "LISTEN",
- "SYN_SENT",
- "SYN_RECEIVED",
- "ESTABLISHED",
- "FIN_WAIT_1",
- "FIN_WAIT_2",
- "CLOSE_WAIT",
- "CLOSING",
- "LAST_ACK",
- "TIME_WAIT"
-};
-
-struct utcp_connection {
- void *priv;
- struct utcp *utcp;
- bool reapable;
-
- uint16_t src;
- uint16_t dst;
- enum state state;
-
- // The following two structures form the TCB
-
- struct {
- uint32_t una;
- uint32_t nxt;
- uint32_t wnd;
- uint32_t iss;
- } snd;
-
- struct {
- uint32_t nxt;
- uint32_t wnd;
- uint32_t irs;
- } rcv;
-
- utcp_recv_t recv;
-
- struct timeval conn_timeout;
- struct timeval rtrx_timeout;
-
- char *sndbuf;
- uint32_t sndbufsize;
-};
-
-struct utcp {
- void *priv;
-
- utcp_accept_t accept;
- utcp_pre_accept_t pre_accept;
- utcp_send_t send;
-
- uint16_t mtu;
- int timeout;
-
- struct utcp_connection **connections;
- int nconnections;
- int nallocated;
-};
+#include "utcp_priv.h"
static void set_state(struct utcp_connection *c, enum state state) {
c->state = state;
fprintf(stderr, " %u -> %u state %s\n", utcp->connections[i]->src, utcp->connections[i]->dst, strstate[utcp->connections[i]->state]);
}
+static int32_t seqdiff(uint32_t a, uint32_t b) {
+ return a - b;
+}
+
// Connections are stored in a sorted list.
// This gives O(log(N)) lookup time, O(N log(N)) insertion time and O(N) deletion time.
else
utcp->nallocated *= 2;
struct utcp_connection **new_array = realloc(utcp->connections, utcp->nallocated * sizeof *utcp->connections);
- if(!new_array) {
- errno = ENOMEM;
+ if(!new_array)
return NULL;
- }
utcp->connections = new_array;
}
struct utcp_connection *c = calloc(1, sizeof *c);
- if(!c) {
- errno = ENOMEM;
+ if(!c)
+ return NULL;
+
+ c->sndbufsize = DEFAULT_SNDBUFSIZE;
+ c->maxsndbufsize = DEFAULT_MAXSNDBUFSIZE;
+ c->sndbuf = malloc(c->sndbufsize);
+ if(!c->sndbuf) {
+ free(c);
return NULL;
}
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
return -1;
}
- uint32_t bufused = c->snd.nxt - c->snd.una;
+ uint32_t bufused = seqdiff(c->snd.nxt, c->snd.una);
+
+ /* Check our send buffer.
+ * - If it's big enough, just put the data in there.
+ * - If not, decide whether to enlarge if possible.
+ * - Cap len so it doesn't overflow our buffer.
+ */
+
+ if(len > c->sndbufsize - bufused && c->sndbufsize < c->maxsndbufsize) {
+ if(c->sndbufsize > c->maxsndbufsize / 2)
+ c->sndbufsize = c->maxsndbufsize;
+ else
+ c->sndbufsize *= 2;
+ c->sndbuf = realloc(c->sndbuf, c->sndbufsize);
+ }
if(len > c->sndbufsize - bufused)
len = c->sndbufsize - bufused;
- memcpy(c->sndbuf + (c->snd.nxt - c->snd.una), data, len);
+ if(!len) {
+ errno == EWOULDBLOCK;
+ return 0;
+ }
+
+ memcpy(c->sndbuf + bufused, data, len);
// Send segments
hdr->dst = tmp;
}
-static int32_t seqdiff(uint32_t a, uint32_t b) {
- return a - b;
-}
-
int utcp_recv(struct utcp *utcp, const void *data, size_t len) {
if(!utcp) {
errno = EFAULT;
break;
case ESTABLISHED:
+ case FIN_WAIT_1:
pkt.hdr.seq = c->snd.una;
pkt.hdr.ack = c->rcv.nxt;
pkt.hdr.ctl = ACK;
uint32_t len = seqdiff(c->snd.nxt, c->snd.una);
+ if(c->state == FIN_WAIT_1)
+ len--;
if(len > utcp->mtu)
len = utcp->mtu;
+ else {
+ if(c->state == FIN_WAIT_1)
+ pkt.hdr.ctl |= FIN;
+ }
memcpy(pkt.data, c->sndbuf, len);
print_packet(c->utcp, "rtrx", &pkt, sizeof pkt.hdr + len);
utcp->send(utcp, &pkt, sizeof pkt.hdr + len);
free(utcp);
}
-int utcp_set_connection_timeout(struct utcp *u, int timeout) {
- int prev = u->timeout;
+uint16_t utcp_get_mtu(struct utcp *utcp) {
+ return utcp->mtu;
+}
+
+void utcp_set_mtu(struct utcp *utcp, uint16_t mtu) {
+ // TODO: handle overhead of the header
+ utcp->mtu = mtu;
+}
+
+int utcp_get_user_timeout(struct utcp *u) {
+ return u->timeout;
+}
+
+void utcp_set_user_timeout(struct utcp *u, int timeout) {
u->timeout = timeout;
- return prev;
+}
+
+size_t utcp_get_sndbuf(struct utcp_connection *c) {
+ return c->maxsndbufsize;
+}
+
+void utcp_set_sndbuf(struct utcp_connection *c, size_t size) {
+ c->maxsndbufsize = size;
+ if(c->maxsndbufsize != size)
+ c->maxsndbufsize = -1;
+}
+
+bool utcp_get_nodelay(struct utcp_connection *c) {
+ return c->nodelay;
+}
+
+void utcp_set_nodelay(struct utcp_connection *c, bool nodelay) {
+ c->nodelay = nodelay;
+}
+
+bool utcp_get_keepalive(struct utcp_connection *c) {
+ return c->keepalive;
+}
+
+void utcp_set_keepalive(struct utcp_connection *c, bool keepalive) {
+ c->keepalive = keepalive;
+}
+
+size_t utcp_get_outq(struct utcp_connection *c) {
+ return seqdiff(c->snd.nxt, c->snd.una);
}
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