imap.c: Use longer libetpan timeout for STATUS and LIST.

Port the LBBS fix for STATUS/LIST libetpan timeouts from: InterLinked1/lbbs@e842676 We do not need to port this LBBS fix for MOVE/COPY libetpan timeouts, since MOVE/COPY in evergreen only handle one message at a time: InterLinked1/lbbs@22f1615 Simplify parsing of STATUS response using ported LBBS optimization from: InterLinked1/lbbs@ce62d96

Author: InterLinked1

imap.c

@@ -283,44 +283,51 @@ static void parse_status(struct client *client, struct mailbox *mbox, char *rest
 return;
 }
 
-str = strstr(tmp, "MESSAGES ");
-if (str) {
-str += STRLEN("MESSAGES ");
-if (!strlen_zero(str)) {
-mbox->total = (uint32_t) atol(str);
-}
-} else if (expect_full) {
-client_warning("Failed to parse MESSAGES");
+/* Helper macro from LBBS mod_webmail.c */
+/* Note: if var, *var = num doesn't work, because that would could be if NULL, *NULL = num.
+ * Since only messages requires the var argument, that case is just hardcoded to compile.
+ * The other checks should boil down to if (NULL) and be optimized out by the compiler. */
+#define PARSE_STATUS_ITEM(item, respitem) \
+str = strstr(tmp, item " "); \
+if (str) { \
+str += STRLEN(item " "); \
+if (!strlen_zero(str)) { \
+mbox->respitem = (uint32_t) atol(str); \
+} \
+} else if (expect_full) { \
+client_warning("Failed to parse " item ""); \
 }
-str = strstr(tmp, "RECENT ");
-if (str) {
-str += STRLEN("RECENT ");
-if (!strlen_zero(str)) {
-mbox->recent = (uint32_t) atol(str);
-}
-} else if (expect_full) {
-client_warning("Failed to parse RECENT");
+
+PARSE_STATUS_ITEM("MESSAGES", total);
+PARSE_STATUS_ITEM("RECENT", recent);
+PARSE_STATUS_ITEM("UNSEEN", unseen);
+if (IMAP_HAS_CAPABILITY(client, IMAP_CAPABILITY_STATUS_SIZE)) {
+PARSE_STATUS_ITEM("SIZE", size);
 }
-str = strstr(tmp, "UNSEEN ");
-if (str) {
-str += STRLEN("UNSEEN ");
-if (!strlen_zero(str)) {
-mbox->unseen = (uint32_t) atol(str);
-}
-} else if (expect_full) {
-client_warning("Failed to parse UNSEEN");
+#undef PARSE_STATUS_ITEM
+}
+
+/* libetpan timeout handling, from LBBS mod_webmail.c */
+#define COMMAND_READ_LARGE_TIMEOUT 45
+
+/*!
+ * \brief Set the mailstream_low timeout, used to determine how long to wait for another line of the response.
+ * \note By default, this timeout appears to be about 15 seconds, but for some commands (e.g. SIZE/LIST), this can be too short.
+ * \param client
+ * \param timeout Timeout, in seconds
+ * \param[out] If provided, old timeout will be stored here.
+ */
+static void set_command_read_timeout(struct client *client, time_t timeout, time_t *restrict old_timeout)
+{
+time_t current_timeout = mailstream_low_get_timeout(mailstream_get_low(client->imap->imap_stream));
+if (old_timeout) {
+*old_timeout = current_timeout;
 }
-if (IMAP_HAS_CAPABILITY(client, IMAP_CAPABILITY_STATUS_SIZE)) {
-str = strstr(tmp, "SIZE ");
-if (str) {
-str += STRLEN("SIZE ");
-if (!strlen_zero(str)) {
-mbox->size = (size_t) atol(str);
-}
-} else if (expect_full) {
-client_warning("Failed to parse SIZE");
-}
+if (current_timeout == timeout) {
+return; /* No change */
 }
+client_debug(4, "Setting libetpan timeout to %ld", timeout);
+return mailstream_low_set_timeout(mailstream_get_low(client->imap->imap_stream), timeout);
 }
 
 int client_status_command(struct client *client, struct mailbox *mbox, char *restrict list_status_resp)
@@ -329,6 +336,7 @@ int client_status_command(struct client *client, struct mailbox *mbox, char *res
 struct mailimap_status_att_list *att_list;
 struct mailimap_mailbox_data_status *status;
 clistiter *cur;
+time_t old_timeout;
 
 /* If LIST-STATUS is supported, we might not need to make a STATUS request at all */
 if (list_status_resp) {
@@ -374,7 +382,9 @@ int client_status_command(struct client *client, struct mailbox *mbox, char *res
 log_mailimap_error(client, res, "Failed to construct STATUS");
 goto cleanup;
 }
+set_command_read_timeout(client, COMMAND_READ_LARGE_TIMEOUT, &old_timeout);
 res = mailimap_status(client->imap, mbox->name, att_list, &status);
+set_command_read_timeout(client, old_timeout, NULL);
 
 if (res != MAILIMAP_NO_ERROR) {
 log_mailimap_error(client, res, "STATUS failed");
@@ -962,6 +972,7 @@ static int __client_list(struct client *client)
 /* This is a single-threaded application, so there is no concurrency risk to making this static/global,
  * and it's probably better to put such a large buffer in the global segment rather than on the stack. */
 static char list_status_buf[32768]; /* Hopefully big enough to fit the entire LIST-STATUS response */
+time_t old_timeout;
 
 #ifdef TEST_MODE
 if (test_cmp(client)) {
@@ -971,6 +982,7 @@ static int __client_list(struct client *client)
 
 client_status("Querying mailbox list");
 
+set_command_read_timeout(client, COMMAND_READ_LARGE_TIMEOUT, &old_timeout);
 if (IMAP_HAS_CAPABILITY(client, IMAP_CAPABILITY_LIST_STATUS) && IMAP_HAS_CAPABILITY(client, IMAP_CAPABILITY_STATUS_SIZE)) {
 struct list_status_cb cb = {
 .buf = list_status_buf,
@@ -989,13 +1001,14 @@ static int __client_list(struct client *client)
 } else {
 res = mailimap_list(client->imap, "", "*", &imap_list);
 }
+set_command_read_timeout(client, old_timeout, NULL); /* Restore */
 
 if (res != MAILIMAP_NO_ERROR) {
 log_mailimap_error(client, res, "LIST failed");
 return -1;
 }
 if (!clist_begin(imap_list)) {
-client_error("List is empty?");
+client_error("LIST response is empty?");
 mailimap_list_result_free(imap_list);
 return -1;
 }