slirp: improve TFTP performance

When transferring a file, keep it open during the whole transfer,
instead of opening/closing it for each block.

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

2 files changed, 13 insertions, 8 deletions

diff --git a/tftp.c b/tftp.c
index 0a9bba6..7009675 100644
--- a/tftp.c
+++ b/tftp.c
@@ -37,6 +37,10 @@ static inline void tftp_session_update(struct tftp_session *spt)
 
 static void tftp_session_terminate(struct tftp_session *spt)
 {
+    if (spt->fd >= 0) {
+        close(spt->fd);
+        spt->fd = -1;
+    }
     g_free(spt->filename);
     spt->slirp = NULL;
 }
@@ -54,7 +58,7 @@ static int tftp_session_allocate(Slirp *slirp, struct tftp_t *tp)
 
         /* sessions time out after 5 inactive seconds */
         if ((int)(curtime - spt->timestamp) > 5000) {
-            g_free(spt->filename);
+            tftp_session_terminate(spt);
             goto found;
         }
     }
@@ -64,6 +68,7 @@ static int tftp_session_allocate(Slirp *slirp, struct tftp_t *tp)
 found:
     memset(spt, 0, sizeof(*spt));
     memcpy(&spt->client_ip, &tp->ip.ip_src, sizeof(spt->client_ip));
+    spt->fd = -1;
     spt->client_port = tp->udp.uh_sport;
     spt->slirp = slirp;
 
@@ -96,23 +101,22 @@ static int tftp_session_find(Slirp *slirp, struct tftp_t *tp)
 static int tftp_read_data(struct tftp_session *spt, uint16_t block_nr,
                           uint8_t *buf, int len)
 {
-    int fd;
     int bytes_read = 0;
 
-    fd = open(spt->filename, O_RDONLY | O_BINARY);
+    if (spt->fd < 0) {
+        spt->fd = open(spt->filename, O_RDONLY | O_BINARY);
+    }
 
-    if (fd < 0) {
+    if (spt->fd < 0) {
         return -1;
     }
 
     if (len) {
-        lseek(fd, block_nr * 512, SEEK_SET);
+        lseek(spt->fd, block_nr * 512, SEEK_SET);
 
-        bytes_read = read(fd, buf, len);
+        bytes_read = read(spt->fd, buf, len);
     }
 
-    close(fd);
-
     return bytes_read;
 }
 
diff --git a/tftp.h b/tftp.h
index 3412e81..b0952e2 100644
--- a/tftp.h
+++ b/tftp.h
@@ -33,6 +33,7 @@ struct tftp_t {
 struct tftp_session {
     Slirp *slirp;
     char *filename;
+    int fd;
 
     struct in_addr client_ip;
     uint16_t client_port;