From 21fc9de47aa4b7fa3a4078e8a89778b2246b085b Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Wed, 16 Jan 2013 20:07:35 +0100
Subject: [PATCH] HTTP keep-alive fixed. Network debugging capabilities.

---
 README.md  | 14 +++++++++-----
 anet.h     |  1 +
 dump1090.c | 36 +++++++++++++++++++++++++++++++-----
 3 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index 07aa3ea..b25efe5 100644
--- a/README.md
+++ b/README.md
@@ -208,27 +208,31 @@ before the first peak to provide some context.
 
 It is possible to display different categories of messages:
 
-    --debug 1       Displays all the messages correctly demoudulated.
+  --debug 1         Displays all the messages correctly demoudulated.
                     A correctly demodulated message is just one that
                     makes sense as a Mode S message, the preamble makes
                     sense, and there are no message errors, that is,
                     no adiacet samples describing bits are the same
                     magnitude.
 
-    --debug 2       Only messages with demodulation errors are displayed,
+ --debug 2          Only messages with demodulation errors are displayed,
                     That is, only messages where one or more adiacent
                     samples that should describe bits are the same
                     magnitude.
 
-    --debug 3       Correctly deooded messages with Bad CRC are displayed.
+ --debug 3          Correctly deooded messages with Bad CRC are displayed.
 
-    --debug 4       Correctly deooded messages with good CRC are displayed.
+ --debug 4          Correctly deooded messages with good CRC are displayed.
 
-    --debug 5       Preamble detection failed in some way (specified when
+ --debug 5          Preamble detection failed in some way (specified when
                     dumping the samples) even if the current sample level
                     is greater than MODES_DEBUG_NOPREAMBLE_LEVEL (set to
                     25 by default).
 
+Network related debug modes:
+
+ --debug 6          Log network events (HTTP requests & others)
+
 How this program works?
 ---
 
diff --git a/anet.h b/anet.h
index 062b22c..6d74af5 100644
--- a/anet.h
+++ b/anet.h
@@ -54,5 +54,6 @@ int anetNonBlock(char *err, int fd);
 int anetTcpNoDelay(char *err, int fd);
 int anetTcpKeepAlive(char *err, int fd);
 int anetPeerToString(int fd, char *ip, int *port);
+int anetSetSendBuffer(char *err, int fd, int buffsize);
 
 #endif
diff --git a/dump1090.c b/dump1090.c
index 0a26901..d895cb7 100644
--- a/dump1090.c
+++ b/dump1090.c
@@ -70,6 +70,7 @@
 #define MODES_DEBUG_BADCRC 3
 #define MODES_DEBUG_GOODCRC 4
 #define MODES_DEBUG_NOPREAMBLE 5
+#define MODES_DEBUG_NET 6
 
 /* When debug is set to MODES_DEBUG_NOPREAMBLE, the first sample must be
  * at least greater than a given level for us to dump the signal. */
@@ -84,6 +85,7 @@
 #define MODES_NET_INPUT_RAW_PORT 30001
 #define MODES_NET_HTTP_PORT 8080
 #define MODES_CLIENT_BUF_SIZE 1024
+#define MODES_NET_SNDBUF_SIZE (1024*64)
 
 #define MODES_NOTUSED(V) ((void) V)
 
@@ -1734,9 +1736,13 @@ void modesAcceptClients(void) {
         c->fd = fd;
         c->buflen = 0;
         Modes.clients[fd] = c;
+        anetSetSendBuffer(Modes.aneterr,fd,MODES_NET_SNDBUF_SIZE);
 
         if (Modes.maxfd < fd) Modes.maxfd = fd;
         j--; /* Try again with the same listening port. */
+
+        if (Modes.debug == MODES_DEBUG_NET)
+            printf("Created new client %d\n", fd);
     }
 }
 
@@ -1746,6 +1752,9 @@ void modesFreeClient(int fd) {
     free(Modes.clients[fd]);
     Modes.clients[fd] = NULL;
 
+    if (Modes.debug == MODES_DEBUG_NET)
+        printf("Closing client %d\n", fd);
+
     /* If this was our maxfd, rescan the full clients array to check what's
      * the new max. */
     if (Modes.maxfd == fd) {
@@ -1901,21 +1910,35 @@ char *aircraftsToJson(int *len) {
 int handleHTTPRequest(struct client *c) {
     char hdr[512];
     int clen, hdrlen;
-    int keepalive;
+    int httpver, keepalive;
     char *p, *url, *content;
     char *ctype;
 
-    /* printf("HTTP request: %s\n", c->buf); */
+    if (Modes.debug == MODES_DEBUG_NET)
+        printf("\nHTTP request: %s\n", c->buf);
 
     /* Minimally parse the request. */
-    keepalive = strstr(c->buf, "keep-alive") != NULL;
+    httpver = (strstr(c->buf, "HTTP/1.1") != NULL) ? 11 : 10;
+    if (httpver == 10) {
+        /* HTTP 1.0 defaults to close, unless otherwise specified. */
+        keepalive = strstr(c->buf, "Connection: keep-alive") != NULL;
+    } else if (httpver == 11) {
+        /* HTTP 1.1 defaults to keep-alive, unless close is specified. */
+        keepalive = strstr(c->buf, "Connection: close") == NULL;
+    }
+
+    /* Identify he URL. */
     p = strchr(c->buf,' ');
     if (!p) return 1; /* There should be the method and a space... */
     url = ++p; /* Now this should point to the requested URL. */
     p = strchr(p, ' ');
     if (!p) return 1; /* There should be a space before HTTP/... */
     *p = '\0';
-    /* printf("URL: %s\n", url); */
+
+    if (Modes.debug == MODES_DEBUG_NET) {
+        printf("\nHTTP keep alive: %d\n", keepalive);
+        printf("HTTP requested URL: %s\n\n", url);
+    }
 
     /* Select the content to send, we have just two so far:
      * "/" -> Our google map application.
@@ -1959,6 +1982,9 @@ int handleHTTPRequest(struct client *c) {
         keepalive ? "keep-alive" : "close",
         clen);
 
+    if (Modes.debug == MODES_DEBUG_NET)
+        printf("HTTP Reply header:\n%s", hdr);
+
     /* Send header and content. */
     if (write(c->fd, hdr, hdrlen) == -1 ||
         write(c->fd, content, clen) == -1)
@@ -1968,7 +1994,7 @@ int handleHTTPRequest(struct client *c) {
     }
     free(content);
     Modes.stat_http_requests++;
-    return 0;
+    return !keepalive;
 }
 
 /* This function polls the clients using read() in order to receive new