BUG/MEDIUM: ssl/crt-list: Rework 'add ssl crt-list' to handle full buffer cases

'add ssl crt-list' command is also concerned. This patch is similar to the
previous ones. Full buffer cases when we try to push the reply are not
properly handled. To fix the issue, the functions responsible to add a
crt-list entry were reworked.

First, the error message is now part of the service context. This way, if we
cannot push the error message in the reponse buffer, we may retry later. To
do so, a dedicated state was created (ADDCRT_ST_ERROR,). Then, the success
message is also handled in a dedicated state (ADDCRT_ST_SUCCESS). This way
we are able to retry to push it if necessary. Finally, the dot displayed for
each new instance is now immediatly pushed in the response buffer, and
before the update. This way, we are able to retry too if necessary.

This patch should fix the issue #1724. It must be backported as far as
2.2. But a massive refactoring was performed in 2.6. So, for the 2.5 and
below, the patch will have to be adapted.

src/ssl_crtlist.c

@@ -43,10 +43,13 @@ struct add_crtlist_ctx {
 	struct crtlist *crtlist;
 	struct crtlist_entry *entry;
 	struct bind_conf_list *bind_conf_node;
+	char *err;
 	enum {
 		ADDCRT_ST_INIT = 0,
 		ADDCRT_ST_GEN,
 		ADDCRT_ST_INSERT,
+		ADDCRT_ST_SUCCESS,
+		ADDCRT_ST_ERROR,
 		ADDCRT_ST_FIN,
 	} state;
 };
@@ -1031,8 +1034,9 @@ static void cli_release_add_crtlist(struct appctx *appctx)
 	struct add_crtlist_ctx *ctx = appctx->svcctx;
 	struct crtlist_entry *entry = ctx->entry;
 
-	if (ctx->state != ADDCRT_ST_FIN) {
+	if (entry) {
 		struct ckch_inst *inst, *inst_s;
+
 		/* upon error free the ckch_inst and everything inside */
 		ebpt_delete(&entry->node);
 		LIST_DELETE(&entry->by_crtlist);
@@ -1046,8 +1050,8 @@ static void cli_release_add_crtlist(struct appctx *appctx)
 		free(entry->ssl_conf);
 		free(entry);
 	}
-
 	HA_SPIN_UNLOCK(CKCH_LOCK, &ckch_lock);
+	ha_free(&ctx->err);
 }
 
 
@@ -1067,26 +1071,21 @@ static int cli_io_handler_add_crtlist(struct appctx *appctx)
 	struct crtlist *crtlist = ctx->crtlist;
 	struct crtlist_entry *entry = ctx->entry;
 	struct ckch_store *store = entry->node.key;
-	struct buffer *trash = alloc_trash_chunk();
 	struct ckch_inst *new_inst;
-	char *err = NULL;
 	int i = 0;
 	int errcode = 0;
 
-	if (trash == NULL)
-		goto error;
-
 	/* for each bind_conf which use the crt-list, a new ckch_inst must be
 	 * created.
 	 */
 	if (unlikely(sc_ic(sc)->flags & (CF_WRITE_ERROR|CF_SHUTW)))
-		goto error;
+		goto end;
 
 	switch (ctx->state) {
 	case ADDCRT_ST_INIT:
 		/* This state just print the update message */
-		chunk_printf(trash, "Inserting certificate '%s' in crt-list '%s'", store->path, crtlist->node.key);
+		chunk_printf(&trash, "Inserting certificate '%s' in crt-list '%s'", store->path, crtlist->node.key);
-		if (applet_putchk(appctx, trash) == -1)
+		if (applet_putchk(appctx, &trash) == -1)
 			goto yield;
 		ctx->state = ADDCRT_ST_GEN;
 		/* fallthrough */
@@ -1098,28 +1097,39 @@ static int cli_io_handler_add_crtlist(struct appctx *appctx)
 			struct bind_conf *bind_conf = bind_conf_node->bind_conf;
 			struct sni_ctx *sni;
 
+			ctx->bind_conf_node = bind_conf_node;
+
 			/* yield every 10 generations */
 			if (i > 10) {
-				ctx->bind_conf_node = bind_conf_node;
+				applet_have_more_data(appctx); /* let's come back later */
 				goto yield;
 			}
 
+			/* display one dot for each new instance */
+			if (applet_putstr(appctx, ".") == -1)
+				goto yield;
+
 			/* we don't support multi-cert bundles, only simple ones */
-			errcode |= ckch_inst_new_load_store(store->path, store, bind_conf, entry->ssl_conf, entry->filters, entry->fcount, &new_inst, &err);
+			ctx->err = NULL;
-			if (errcode & ERR_CODE)
+			errcode |= ckch_inst_new_load_store(store->path, store, bind_conf, entry->ssl_conf, entry->filters, entry->fcount, &new_inst, &ctx->err);
+			if (errcode & ERR_CODE) {
+				ctx->state = ADDCRT_ST_ERROR;
 				goto error;
+			}
 
 			/* we need to initialize the SSL_CTX generated */
 			/* this iterate on the newly generated SNIs in the new instance to prepare their SSL_CTX */
 			list_for_each_entry(sni, &new_inst->sni_ctx, by_ckch_inst) {
 				if (!sni->order) { /* we initialized only the first SSL_CTX because it's the same in the other sni_ctx's */
-					errcode |= ssl_sock_prep_ctx_and_inst(bind_conf, new_inst->ssl_conf, sni->ctx, sni->ckch_inst, &err);
+					ctx->err = NULL;
-					if (errcode & ERR_CODE)
+					errcode |= ssl_sock_prep_ctx_and_inst(bind_conf, new_inst->ssl_conf, sni->ctx, sni->ckch_inst, &ctx->err);
+					if (errcode & ERR_CODE) {
+						ctx->state = ADDCRT_ST_ERROR;
 						goto error;
+					}
 				}
 			}
-			/* display one dot for each new instance */
+
-			chunk_appendf(trash, ".");
 			i++;
 			LIST_APPEND(&store->ckch_inst, &new_inst->by_ckchs);
 			LIST_APPEND(&entry->ckch_inst, &new_inst->by_crtlist_entry);
@@ -1135,36 +1145,36 @@ static int cli_io_handler_add_crtlist(struct appctx *appctx)
 			HA_RWLOCK_WRUNLOCK(SNI_LOCK, &new_inst->bind_conf->sni_lock);
 		}
 		entry->linenum = ++crtlist->linecount;
-		ctx->state = ADDCRT_ST_FIN;
+		ctx->entry = NULL;
+		ctx->state = ADDCRT_ST_SUCCESS;
 		/* fallthrough */
+	case ADDCRT_ST_SUCCESS:
+		chunk_reset(&trash);
+		chunk_appendf(&trash, "\n");
+		if (ctx->err)
+			chunk_appendf(&trash, "%s", ctx->err);
+		chunk_appendf(&trash, "Success!\n");
+		if (applet_putchk(appctx, &trash) == -1)
+			goto yield;
+		ctx->state = ADDCRT_ST_FIN;
+		break;
+
+	case ADDCRT_ST_ERROR:
+	  error:
+		chunk_printf(&trash, "\n%sFailed!\n", ctx->err);
+		if (applet_putchk(appctx, &trash) == -1)
+			goto yield;
+		break;
+
 	default:
 		break;
 	}
 
-	chunk_appendf(trash, "\n");
+end:
-	if (errcode & ERR_WARN)
-		chunk_appendf(trash, "%s", err);
-	chunk_appendf(trash, "Success!\n");
-	applet_putchk(appctx, trash);
-	free_trash_chunk(trash);
 	/* success: call the release function and don't come back */
 	return 1;
 yield:
-	/* store the state */
-	applet_putchk(appctx, trash);
-	free_trash_chunk(trash);
-	applet_have_more_data(appctx); /* let's come back later */
 	return 0; /* should come back */
-
-error:
-	/* spin unlock and free are done in the release function */
-	if (trash) {
-		chunk_appendf(trash, "\n%sFailed!\n", err);
-		applet_putchk(appctx, trash);
-		free_trash_chunk(trash);
-	}
-	/* error: call the release function and don't come back */
-	return 1;
 }