MINOR: spoe: Use the min of all known max_frame_size to encode messages

The max_frame_size value is negociated between HAProxy and SPOE agents during
the HELLO handshake. It is a per-connection value. Different SPOE agents can
choose to use different max_frame_size values. So, now, we keep the minimum of
all known max_frame_size. This minimum is updated when a new connection to a
SPOE agent is opened and when a connection is closed. We use this value as a
limit to encode messages in NOTIFY frames.

diff --git a/src/flt_spoe.c b/src/flt_spoe.c
index f4da4ddd7caa82b183dd2a3a11f6f96c0916fe7c..f3bdfc3b9b9d7e2328981b93011aa65dec2070da 100644 (file)
--- a/src/flt_spoe.c
+++ b/src/flt_spoe.c
@@ -49,8 +49,16 @@
 #define SPOE_PRINTF(x...)
 #endif
 
-/* Minimal size for a frame */
-#define MIN_FRAME_SIZE 256
+/* Reserved 4 bytes to the frame size. So a frame and its size can be written
+ * together in a buffer */
+#define MAX_FRAME_SIZE     global.tune.bufsize - 4
+
+/* The minimum size for a frame */
+#define MIN_FRAME_SIZE     256
+
+/* Reserved for the metadata and the frame type.  So <MAX_FRAME_SIZE> -
+ * <FRAME_HDR_SIZE> is the maximum payload size */
+#define FRAME_HDR_SIZE     32
 
 /* Flags set on the SPOE agent */
 #define SPOE_FL_CONT_ON_ERR       0x00000001 /* Do not stop events processing when an error occurred */
@@ -219,6 +227,7 @@ struct spoe_agent {
                                               * for each supported events */
 
        /* running info */
+       unsigned int          frame_size;     /* current maximum frame size, only used to encode messages */
        unsigned int          applets_act;    /* # of applets alive at a time */
        unsigned int          applets_idle;   /* # of applets in the state SPOE_APPCTX_ST_IDLE */
        unsigned int          sending_rate;   /* the global sending rate */
@@ -1260,7 +1269,7 @@ prepare_spoe_healthcheck_request(char **req, int *len)
 {
        struct appctx       appctx;
        struct spoe_appctx  spoe_appctx;
-       char               *frame, buf[global.tune.bufsize];
+       char               *frame, buf[MAX_FRAME_SIZE+4];
        unsigned int        framesz;
        int                 idx;
 
@@ -1269,13 +1278,13 @@ prepare_spoe_healthcheck_request(char **req, int *len)
        memset(buf, 0, sizeof(buf));
 
        appctx.ctx.spoe.ptr = &spoe_appctx;
-       SPOE_APPCTX(&appctx)->max_frame_size = global.tune.bufsize-4;
+       SPOE_APPCTX(&appctx)->max_frame_size = MAX_FRAME_SIZE;
 
        frame = buf+4;
-       idx = prepare_spoe_hahello_frame(&appctx, frame, global.tune.bufsize-4);
+       idx = prepare_spoe_hahello_frame(&appctx, frame, MAX_FRAME_SIZE);
        if (idx <= 0)
                return -1;
-       if (idx + SLEN(HEALTHCHECK_KEY) + 1 > global.tune.bufsize-4)
+       if (idx + SLEN(HEALTHCHECK_KEY) + 1 > MAX_FRAME_SIZE)
                return -1;
 
        /* "healthcheck" K/V item */
@@ -1306,7 +1315,7 @@ handle_spoe_healthcheck_response(char *frame, size_t size, char *err, int errlen
        memset(&spoe_appctx, 0, sizeof(spoe_appctx));
 
        appctx.ctx.spoe.ptr = &spoe_appctx;
-       SPOE_APPCTX(&appctx)->max_frame_size = global.tune.bufsize-4;
+       SPOE_APPCTX(&appctx)->max_frame_size = MAX_FRAME_SIZE;
 
        if (handle_spoe_agentdiscon_frame(&appctx, frame, size) != 0)
                goto error;
@@ -1418,6 +1427,7 @@ release_spoe_applet(struct appctx *appctx)
        struct stream_interface *si    = appctx->owner;
        struct spoe_agent       *agent = SPOE_APPCTX(appctx)->agent;
        struct spoe_context     *ctx, *back;
+       struct spoe_appctx      *spoe_appctx;
 
        SPOE_PRINTF(stderr, "%d.%06d [SPOE/%-15s] %s: appctx=%p\n",
                    (int)now.tv_sec, (int)now.tv_usec, agent->id,
@@ -1458,7 +1468,7 @@ release_spoe_applet(struct appctx *appctx)
        pool_free2(pool2_spoe_appctx, SPOE_APPCTX(appctx));
 
        if (!LIST_ISEMPTY(&agent->applets))
-               return;
+               goto end;
 
        list_for_each_entry_safe(ctx, back, &agent->sending_queue, list) {
                LIST_DEL(&ctx->list);
@@ -1475,6 +1485,12 @@ release_spoe_applet(struct appctx *appctx)
                ctx->status_code = (SPOE_APPCTX(appctx)->status_code + 0x100);
                task_wakeup(ctx->strm->task, TASK_WOKEN_MSG);
        }
+
+  end:
+       /* Update runtinme agent info */
+       agent->frame_size = agent->max_frame_size;
+       list_for_each_entry(spoe_appctx, &agent->applets, list)
+               agent->frame_size = MIN(spoe_appctx->max_frame_size, agent->frame_size);
 }
 
 static int
@@ -1592,6 +1608,9 @@ handle_connecting_spoe_applet(struct appctx *appctx)
                        appctx->st0 = SPOE_APPCTX_ST_IDLE;
                        LIST_DEL(&SPOE_APPCTX(appctx)->list);
                        LIST_ADD(&agent->applets, &SPOE_APPCTX(appctx)->list);
+
+                       /* Update runtinme agent info */
+                       agent->frame_size = MIN(SPOE_APPCTX(appctx)->max_frame_size, agent->frame_size);
                        goto next;
        }
 
@@ -2145,8 +2164,7 @@ process_spoe_messages(struct stream *s, struct spoe_context *ctx,
        size_t  max_size;
        int     off, flag, idx = 0;
 
-       /* Reserve 32 bytes from the frame Metadata */
-       max_size = agent->max_frame_size - 32;
+       max_size = agent->frame_size - FRAME_HDR_SIZE;
 
        p = ctx->buffer->p;
 
@@ -3040,13 +3058,14 @@ cfg_parse_spoe_agent(const char *file, int linenum, char **args, int kwm)
                curagent->flags          = 0;
                curagent->cps_max        = 0;
                curagent->eps_max        = 0;
-               curagent->max_frame_size = global.tune.bufsize - 4;
+               curagent->max_frame_size = MAX_FRAME_SIZE;
                curagent->min_applets    = 0;
                curagent->max_fpa        = 100;
 
                for (i = 0; i < SPOE_EV_EVENTS; ++i)
                        LIST_INIT(&curagent->messages[i]);
 
+               curagent->frame_size   = curagent->max_frame_size;
                curagent->applets_act  = 0;
                curagent->applets_idle = 0;
                curagent->sending_rate = 0;