1 files changed, 42 insertions, 21 deletions

diff --git a/ot_http.c b/ot_http.c
index d4c7363..bb6ff24 100644
--- a/ot_http.c
+++ b/ot_http.c
@@ -6,6 +6,7 @@
 /* System */
 #define _GNU_SOURCE
 #include <arpa/inet.h>
+#include <errno.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -38,9 +39,25 @@ ssize_t      g_stats_path_len;
 
 enum { SUCCESS_HTTP_HEADER_LENGTH = 80, SUCCESS_HTTP_SIZE_OFF = 17 };
 
-/* Give up a connection: the one place that knows everything hanging off it.
-   The slot is released before anything is freed, so that a late event or the
-   expiry sweep finds a closed descriptor rather than a freed cookie. */
+int http_adopt(const int64_t sock, struct http_data *cookie) {
+  struct http_data *heap = malloc(sizeof(*heap));
+
+  if (!heap)
+    return -1;
+
+  *heap = *cookie;
+  heap->flag &= ~STRUCT_HTTP_FLAG_ONSTACK;
+  fdstate_set_cookie((int)sock, heap);
+
+  if (event_add((int)sock, heap->interest, fdstate_generation((int)sock)) == -1) {
+    fdstate_set_cookie((int)sock, cookie);
+    free(heap);
+    return -1;
+  }
+  return 0;
+}
+
+/* Give up a connection: the one place that knows everything hanging off it. */
 void http_close(const int64_t sock) {
   struct http_data *cookie = fdstate_cookie(sock);
 
@@ -53,7 +70,8 @@ void http_close(const int64_t sock) {
     buf_reset(&cookie->request);
     if (cookie->flag & (STRUCT_HTTP_FLAG_WAITINGFORTASK | STRUCT_HTTP_FLAG_CHUNKED_IN_TRANSFER))
       mutex_workqueue_canceltask(sock);
-    free(cookie);
+    if (!(cookie->flag & STRUCT_HTTP_FLAG_ONSTACK))
+      free(cookie);
   }
 
   event_close((int)sock);
@@ -85,6 +103,12 @@ static void http_senddata(const int64_t sock, struct ot_workstruct *ws) {
     buf_reset(&cookie->request);
 
   written_size = write(sock, ws->reply, ws->reply_size);
+  /* A send buffer with no room in it is not a failure: nothing went out, so
+     the whole reply goes into the batch below and leaves when the socket
+     drains. Only a real error ends the connection here. */
+  if (written_size < 0 && (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR))
+    written_size = 0;
+
   if ((written_size < 0) || ((written_size == ws->reply_size) && !ws->keep_alive)) {
     http_close(sock);
     return;
@@ -111,11 +135,9 @@ static void http_senddata(const int64_t sock, struct ot_workstruct *ws) {
     batch_add(cookie->batch, outbuf, ws->reply_size - written_size);
 
     /* writeable short data sockets just have a tcp timeout */
-    if (!ws->keep_alive) {
+    if (!ws->keep_alive)
       fdstate_set_expiry(sock, 0);
-      http_interest_drop(sock, cookie, EVENT_IN);
-    }
-    http_interest_add(sock, cookie, EVENT_OUT);
+    http_interest_set(sock, cookie, EVENT_OUT);
   }
 }
 
@@ -128,21 +150,20 @@ static void http_senddata(const int64_t sock, struct ot_workstruct *ws) {
 #define HTTPERROR_403_IP         return http_issue_error(sock, ws, CODE_HTTPERROR_403_IP)
 #define HTTPERROR_404            return http_issue_error(sock, ws, CODE_HTTPERROR_404)
 #define HTTPERROR_500            return http_issue_error(sock, ws, CODE_HTTPERROR_500)
-static void http_interest(const int64_t sock, struct http_data *cookie, int what) {
+/* A connection is either being read or being written, never both, so what it
+   waits for is set outright rather than added to and taken away again. The
+   event layer only hears about it when the answer changes. */
+void http_interest_set(const int64_t sock, struct http_data *cookie, int what) {
   if (cookie->interest == what)
     return;
   cookie->interest = what;
+  /* Still on a stack, so not in the event loop yet: whoever adopts this
+     connection registers whatever it asked for last */
+  if (cookie->flag & STRUCT_HTTP_FLAG_ONSTACK)
+    return;
   event_modify((int)sock, what, fdstate_generation((int)sock));
 }
 
-void http_interest_add(const int64_t sock, struct http_data *cookie, int what) {
-  http_interest(sock, cookie, cookie->interest | what);
-}
-
-void http_interest_drop(const int64_t sock, struct http_data *cookie, int what) {
-  http_interest(sock, cookie, cookie->interest & ~what);
-}
-
 ssize_t http_issue_error(const int64_t sock, struct ot_workstruct *ws, int code) {
   const char *error_code[] = {"302 Found",      "400 Invalid Request", "400 Invalid Request", "400 Invalid Request",      "402 Payment Required",
                         "403 Not Modest", "403 Access Denied",   "404 Not Found",       "500 Internal Server Error"};
@@ -187,7 +208,7 @@ ssize_t http_sendiovecdata(const int64_t sock, struct ot_workstruct *ws, size_t
 
   /* If we came here, wait for the answer is over */
   if (cookie->flag & STRUCT_HTTP_FLAG_WAITINGFORTASK) {
-    http_interest_drop(sock, cookie, EVENT_IN);
+    http_interest_set(sock, cookie, 0);
     cookie->flag &= ~STRUCT_HTTP_FLAG_WAITINGFORTASK;
   }
 
@@ -238,7 +259,7 @@ ssize_t http_sendiovecdata(const int64_t sock, struct ot_workstruct *ws, size_t
   }
 
   fdstate_set_expiry(sock, time_future_seconds(OT_CLIENT_TIMEOUT_SEND));
-  http_interest_add(sock, cookie, EVENT_OUT);
+  http_interest_set(sock, cookie, EVENT_OUT);
   return 0;
 }
 
@@ -333,7 +354,7 @@ static ssize_t http_handle_stats(const int64_t sock, struct ot_workstruct *ws, c
     /* Clients waiting for us should not easily timeout */
     fdstate_set_expiry(sock, 0);
     fullscrape_deliver(sock, format);
-    http_interest_drop(sock, cookie, EVENT_IN);
+    http_interest_set(sock, cookie, 0);
     return ws->reply_size = -2;
   }
 #endif
@@ -428,7 +449,7 @@ static ssize_t http_handle_fullscrape(const int64_t sock, struct ot_workstruct *
   /* Clients waiting for us should not easily timeout */
   fdstate_set_expiry(sock, 0);
   fullscrape_deliver(sock, format);
-  http_interest_drop(sock, cookie, EVENT_IN);
+  http_interest_set(sock, cookie, 0);
   return ws->reply_size = -2;
 }
 #endif