sync with latest 0.9.0pre1
[claws.git] / src / imap.c
index ac720e433bfa1bf2a6055ba44ea7491b92adff18..8d7b6c4c6d3fdfb336ff07998dd1c889585a457f 100644 (file)
 #  include <iconv.h>
 #endif
 
+#if USE_OPENSSL
+#  include "ssl.h"
+#endif
+#include "folder.h"
+#include "session.h"
+#include "procmsg.h"
 #include "intl.h"
 #include "imap.h"
 #include "socket.h"
 #include "ssl.h"
 #include "recv.h"
-#include "procmsg.h"
 #include "procheader.h"
-#include "folder.h"
 #include "prefs_account.h"
 #include "codeconv.h"
 #include "utils.h"
 #include "inputdialog.h"
 #include "log.h"
 
+typedef struct _IMAPFolder     IMAPFolder;
+typedef struct _IMAPSession    IMAPSession;
+typedef struct _IMAPNameSpace  IMAPNameSpace;
+typedef struct _IMAPFolderItem IMAPFolderItem;
+
+#include "prefs_account.h"
+
+#define IMAP_FOLDER(obj)       ((IMAPFolder *)obj)
+#define IMAP_SESSION(obj)      ((IMAPSession *)obj)
+
+struct _IMAPFolder
+{
+       RemoteFolder rfolder;
+
+       /* list of IMAPNameSpace */
+       GList *ns_personal;
+       GList *ns_others;
+       GList *ns_shared;
+};
+
+struct _IMAPSession
+{
+       Session session;
+
+       gchar **capability;
+       gchar *mbox;
+       time_t last_access_time;
+       gboolean authenticated;
+       guint cmd_count;
+};
+
+struct _IMAPNameSpace
+{
+       gchar *name;
+       gchar separator;
+};
+
+#define IMAP_SUCCESS   0
+#define IMAP_SOCKET    2
+#define IMAP_AUTHFAIL  3
+#define IMAP_PROTOCOL  4
+#define IMAP_SYNTAX    5
+#define IMAP_IOERR     6
+#define IMAP_ERROR     7
+
+#define IMAPBUFSIZE    8192
+
+typedef enum
+{
+       IMAP_FLAG_SEEN          = 1 << 0,
+       IMAP_FLAG_ANSWERED      = 1 << 1,
+       IMAP_FLAG_FLAGGED       = 1 << 2,
+       IMAP_FLAG_DELETED       = 1 << 3,
+       IMAP_FLAG_DRAFT         = 1 << 4
+} IMAPFlags;
+
+#define IMAP_IS_SEEN(flags)    ((flags & IMAP_FLAG_SEEN) != 0)
+#define IMAP_IS_ANSWERED(flags)        ((flags & IMAP_FLAG_ANSWERED) != 0)
+#define IMAP_IS_FLAGGED(flags) ((flags & IMAP_FLAG_FLAGGED) != 0)
+#define IMAP_IS_DELETED(flags) ((flags & IMAP_FLAG_DELETED) != 0)
+#define IMAP_IS_DRAFT(flags)   ((flags & IMAP_FLAG_DRAFT) != 0)
+
+
 #define IMAP4_PORT     143
 #if USE_OPENSSL
 #define IMAPS_PORT     993
@@ -83,7 +150,7 @@ struct _IMAPFolderItem
 static Folder *imap_folder_new(const gchar * name, const gchar * path);
 static void imap_folder_destroy(Folder * folder);
 
-static Session *imap_session_new(const PrefsAccount * account);
+static IMAPSession *imap_session_new(const PrefsAccount * account);
 static void imap_session_authenticate(IMAPSession * session,
                                      const PrefsAccount * account);
 static void imap_session_destroy(Session * session);
@@ -115,8 +182,6 @@ static gint imap_rename_folder(Folder * folder,
 static gint imap_remove_folder(Folder * folder, FolderItem * item);
 
 
-static gint imap_cmd_count = 0;
-
 static void imap_folder_init           (Folder         *folder,
                                         const gchar    *name,
                                         const gchar    *path);
@@ -211,55 +276,54 @@ static MsgFlags imap_parse_flags  (const gchar    *flag_str);
 static MsgInfo *imap_parse_envelope    (SockInfo       *sock,
                                         FolderItem     *item,
                                         GString        *line_str);
-static gint imap_greeting              (SockInfo       *sock,
-                                        gboolean       *is_preauth);
-static void imap_get_capability                (Session        *session);
+static gint imap_greeting              (IMAPSession    *session);
 static gboolean imap_has_capability    (IMAPSession    *session,
                                         const gchar    *cap);
+void imap_free_capabilities            (IMAPSession    *session);
 static const IMAPSet numberlist_to_imapset(MsgNumberList *list);
 
 /* low-level IMAP4rev1 commands */
-static gint imap_cmd_login     (SockInfo       *sock,
+static gint imap_cmd_login     (IMAPSession    *sock,
                                 const gchar    *user,
                                 const gchar    *pass);
-static gint imap_cmd_logout    (SockInfo       *sock);
-static gint imap_cmd_noop      (SockInfo       *sock);
-static gint imap_cmd_starttls  (SockInfo       *sock);
-static gint imap_cmd_namespace (SockInfo       *sock,
+static gint imap_cmd_logout    (IMAPSession    *sock);
+static gint imap_cmd_noop      (IMAPSession    *sock);
+static gint imap_cmd_starttls  (IMAPSession    *sock);
+static gint imap_cmd_namespace (IMAPSession    *sock,
                                 gchar         **ns_str);
-static gint imap_cmd_list      (SockInfo       *sock,
+static gint imap_cmd_list      (IMAPSession    *session,
                                 const gchar    *ref,
                                 const gchar    *mailbox,
                                 GPtrArray      *argbuf);
-static gint imap_cmd_do_select (SockInfo       *sock,
+static gint imap_cmd_do_select (IMAPSession    *sock,
                                 const gchar    *folder,
                                 gboolean        examine,
                                 gint           *exists,
                                 gint           *recent,
                                 gint           *unseen,
                                 guint32        *uid_validity);
-static gint imap_cmd_select    (SockInfo       *sock,
+static gint imap_cmd_select    (IMAPSession    *sock,
                                 const gchar    *folder,
                                 gint           *exists,
                                 gint           *recent,
                                 gint           *unseen,
                                 guint32        *uid_validity);
-static gint imap_cmd_examine   (SockInfo       *sock,
+static gint imap_cmd_examine   (IMAPSession    *sock,
                                 const gchar    *folder,
                                 gint           *exists,
                                 gint           *recent,
                                 gint           *unseen,
                                 guint32        *uid_validity);
-static gint imap_cmd_create    (SockInfo       *sock,
+static gint imap_cmd_create    (IMAPSession    *sock,
                                 const gchar    *folder);
-static gint imap_cmd_rename    (SockInfo       *sock,
+static gint imap_cmd_rename    (IMAPSession    *sock,
                                 const gchar    *oldfolder,
                                 const gchar    *newfolder);
-static gint imap_cmd_delete    (SockInfo       *sock,
+static gint imap_cmd_delete    (IMAPSession    *sock,
                                 const gchar    *folder);
-static gint imap_cmd_envelope  (SockInfo       *sock,
+static gint imap_cmd_envelope  (IMAPSession    *sock,
                                 IMAPSet         set);
-static gint imap_cmd_fetch     (SockInfo       *sock,
+static gint imap_cmd_fetch     (IMAPSession    *sock,
                                 guint32         uid,
                                 const gchar    *filename);
 static gint imap_cmd_append    (IMAPSession    *session,
@@ -270,16 +334,16 @@ static gint imap_cmd_copy (IMAPSession    *session,
                                 gint32         msgnum,
                                 const gchar    *destfolder,
                                 gint32         *new_uid);
-static gint imap_cmd_store     (SockInfo       *sock,
+static gint imap_cmd_store     (IMAPSession    *sock,
                                 IMAPSet         set,
                                 gchar          *sub_cmd);
-static gint imap_cmd_expunge   (SockInfo       *sock);
+static gint imap_cmd_expunge   (IMAPSession    *sock);
 
-static gint imap_cmd_ok                (SockInfo       *sock,
+static gint imap_cmd_ok                (IMAPSession    *session,
                                 GPtrArray      *argbuf);
-static void imap_cmd_gen_send  (SockInfo       *sock,
+static void imap_gen_send      (IMAPSession    *sock,
                                 const gchar    *format, ...);
-static gint imap_cmd_gen_recv  (SockInfo       *sock,
+static gint imap_gen_recv      (IMAPSession    *sock,
                                 gchar         **buf);
 
 /* misc utility functions */
@@ -355,7 +419,7 @@ FolderClass imap_class =
        imap_change_flags,
 };
 
-FolderClass *imap_get_class()
+FolderClass *imap_get_class(void)
 {
        return &imap_class;
 }
@@ -435,7 +499,7 @@ static void imap_reset_uid_lists(Folder *folder)
 static IMAPSession *imap_session_get(Folder *folder)
 {
        RemoteFolder *rfolder = REMOTE_FOLDER(folder);
-       Session *session = NULL;
+       IMAPSession *session = NULL;
        gushort port;
 
        g_return_val_if_fail(folder != NULL, NULL);
@@ -453,7 +517,7 @@ static IMAPSession *imap_session_get(Folder *folder)
 
        /* Make sure we have a session */
        if (rfolder->session != NULL) {
-               session = rfolder->session;
+               session = IMAP_SESSION(rfolder->session);
        } else {
                imap_reset_uid_lists(folder);
                session = imap_session_new(folder->account);
@@ -461,21 +525,18 @@ static IMAPSession *imap_session_get(Folder *folder)
        if(session == NULL)
                return NULL;
 
-       if (session->sock->state == CONN_DISCONNECTED) {
+       if (SESSION(session)->sock->state == CONN_DISCONNECTED) {
                debug_print("IMAP server disconnected\n");
-               session_destroy(session);
+               session_destroy(SESSION(session));
                imap_reset_uid_lists(folder);
                session = imap_session_new(folder->account);
-       }               
-
-       /* Get CAPABILITY */
-       imap_get_capability(session); 
+       }
 
        /* Make sure session is authenticated */
        if (!IMAP_SESSION(session)->authenticated)
                imap_session_authenticate(IMAP_SESSION(session), folder->account);
        if (!IMAP_SESSION(session)->authenticated) {
-               session_destroy(session);
+               session_destroy(SESSION(session));
                rfolder->session = NULL;
                return NULL;
        }
@@ -494,37 +555,37 @@ static IMAPSession *imap_session_get(Folder *folder)
         * successfully sent. -- mbp */
        if (time(NULL) - session->last_access_time > SESSION_TIMEOUT) {
                /* verify that the session is still alive */
-               if (imap_cmd_noop(session->sock) != IMAP_SUCCESS) {
+               if (imap_cmd_noop(session) != IMAP_SUCCESS) {
                        /* Check if this is the first try to establish a
                           connection, if yes we don't try to reconnect */
                        if (rfolder->session == NULL) {
                                log_warning(_("Connecting %s:%d failed"),
                                            folder->account->recv_server, port);
-                               session_destroy(session);
+                               session_destroy(SESSION(session));
                                session = NULL;
                        } else {
                                log_warning(_("IMAP4 connection to %s:%d has been"
                                              " disconnected. Reconnecting...\n"),
                                            folder->account->recv_server, port);
-                               session_destroy(session);
+                               session_destroy(SESSION(session));
                                /* Clear folders session to make imap_session_get create
                                   a new session, because of rfolder->session == NULL
                                   it will not try to reconnect again and so avoid an
                                   endless loop */
                                rfolder->session = NULL;
-                               session = SESSION(imap_session_get(folder));
+                               session = imap_session_get(folder);
                        }
                }
        }
 
-       rfolder->session = session;
+       rfolder->session = SESSION(session);
        if (session) {
                session->last_access_time = time(NULL);
        }
        return IMAP_SESSION(session);
 }
 
-Session *imap_session_new(const PrefsAccount *account)
+IMAPSession *imap_session_new(const PrefsAccount *account)
 {
        IMAPSession *session;
        SockInfo *imap_sock;
@@ -569,14 +630,6 @@ Session *imap_session_new(const PrefsAccount *account)
                        return NULL;
        }
 
-       /* Only need to log in if the connection was not PREAUTH */
-       if (imap_greeting(imap_sock, &is_preauth) != IMAP_SUCCESS) {
-               sock_close(imap_sock);
-               return NULL;
-       }
-       log_message("IMAP connection is %s-authenticated\n",
-                   (is_preauth) ? "pre" : "un");
-
        session = g_new0(IMAPSession, 1);
        session_init(SESSION(session));
        SESSION(session)->type             = SESSION_IMAP;
@@ -589,8 +642,43 @@ Session *imap_session_new(const PrefsAccount *account)
 
        session->mbox = NULL;
        session->authenticated = is_preauth;
+       session->cmd_count = 0;
+
+       /* Only need to log in if the connection was not PREAUTH */
+       if (imap_greeting(session) != IMAP_SUCCESS) {
+               session_destroy(SESSION(session));
+               return NULL;
+       }
+
+#if USE_OPENSSL
+       if (account->ssl_imap == SSL_STARTTLS && imap_has_capability(session, "STARTTLS")) {
+               gint ok;
+
+               ok = imap_cmd_starttls(session);
+               if (ok != IMAP_SUCCESS) {
+                       log_warning(_("Can't start TLS session.\n"));
+                       session_destroy(SESSION(session));
+                       return NULL;
+               }
+               if (!ssl_init_socket_with_method(SESSION(session)->sock, SSL_METHOD_TLSv1)) {
+                       session_destroy(SESSION(session));
+                       return NULL;
+               }
+
+               imap_free_capabilities(session);
+               session->authenticated = is_preauth;
+               session->cmd_count = 1;
 
-       return SESSION(session);
+               if (imap_greeting(session) != IMAP_SUCCESS) {
+                       session_destroy(SESSION(session));
+                       return NULL;
+               }               
+       }
+#endif
+       log_message("IMAP connection is %s-authenticated\n",
+                   (is_preauth) ? "pre" : "un");
+
+       return session;
 }
 
 void imap_session_authenticate(IMAPSession *session, const PrefsAccount *account)
@@ -609,8 +697,8 @@ void imap_session_authenticate(IMAPSession *session, const PrefsAccount *account
                g_free(tmp_pass);
        }
 
-       if (imap_cmd_login(SESSION(session)->sock, account->userid, pass) != IMAP_SUCCESS) {
-               imap_cmd_logout(SESSION(session)->sock);
+       if (imap_cmd_login(session, account->userid, pass) != IMAP_SUCCESS) {
+               imap_cmd_logout(session);
                return;
        }
 
@@ -623,8 +711,7 @@ void imap_session_destroy(Session *session)
        session->sock = NULL;
 
        g_free(IMAP_SESSION(session)->mbox);
-
-       g_strfreev(IMAP_SESSION(session)->capability);
+       imap_free_capabilities(IMAP_SESSION(session));
 }
 
 gchar *imap_fetch_msg(Folder *folder, FolderItem *item, gint uid)
@@ -662,7 +749,7 @@ gchar *imap_fetch_msg(Folder *folder, FolderItem *item, gint uid)
        }
 
        debug_print("getting message %d...\n", uid);
-       ok = imap_cmd_fetch(SESSION(session)->sock, (guint32)uid, filename);
+       ok = imap_cmd_fetch(session, (guint32)uid, filename);
 
        if (ok != IMAP_SUCCESS) {
                g_warning("can't fetch message %d\n", uid);
@@ -752,7 +839,7 @@ static gint imap_do_copy(Folder *folder, FolderItem *dest, MsgInfo *msginfo,
                
                imap_set_message_flags(session, &numlist,
                                       IMAP_FLAG_DELETED, TRUE);
-               ok = imap_cmd_expunge(SESSION(session)->sock);
+               ok = imap_cmd_expunge(session);
        }
 
        g_free(destdir);
@@ -816,7 +903,7 @@ gint imap_remove_msg(Folder *folder, FolderItem *item, gint uid)
                return ok;
        }
 
-       ok = imap_cmd_expunge(SESSION(session)->sock);
+       ok = imap_cmd_expunge(session);
        if (ok != IMAP_SUCCESS) {
                log_warning(_("can't expunge\n"));
                return ok;
@@ -851,15 +938,15 @@ gint imap_remove_all_msg(Folder *folder, FolderItem *item)
        if (exists == 0)
                return IMAP_SUCCESS;
 
-       imap_cmd_gen_send(SESSION(session)->sock,
-                         "STORE 1:%d +FLAGS (\\Deleted)", exists);
-       ok = imap_cmd_ok(SESSION(session)->sock, NULL);
+       imap_gen_send(session,
+                     "STORE 1:%d +FLAGS (\\Deleted)", exists);
+       ok = imap_cmd_ok(session, NULL);
        if (ok != IMAP_SUCCESS) {
                log_warning(_("can't set deleted flags: 1:%d\n"), exists);
                return ok;
        }
 
-       ok = imap_cmd_expunge(SESSION(session)->sock);
+       ok = imap_cmd_expunge(session);
        if (ok != IMAP_SUCCESS) {
                log_warning(_("can't expunge\n"));
                return ok;
@@ -979,8 +1066,8 @@ static gint imap_scan_tree_recursive(IMAPSession *session, FolderItem *item)
                  {g_free(real_path); return IMAP_ERROR;});
        QUOTE_IF_REQUIRED(wildcard_path, wildcard_path);
 
-       imap_cmd_gen_send(SESSION(session)->sock, "LIST \"\" %s",
-                         wildcard_path);
+       imap_gen_send(session, "LIST \"\" %s",
+                     wildcard_path);
 
        strtailchomp(real_path, separator);
        item_list = imap_parse_list(folder, session, real_path, NULL);
@@ -1228,7 +1315,7 @@ FolderItem *imap_create_folder(Folder *folder, FolderItem *parent,
                gboolean exist = FALSE;
 
                argbuf = g_ptr_array_new();
-               ok = imap_cmd_list(SESSION(session)->sock, NULL, imap_path,
+               ok = imap_cmd_list(session, NULL, imap_path,
                                   argbuf);
                if (ok != IMAP_SUCCESS) {
                        log_warning(_("can't create mailbox: LIST failed\n"));
@@ -1251,7 +1338,7 @@ FolderItem *imap_create_folder(Folder *folder, FolderItem *parent,
                g_ptr_array_free(argbuf, TRUE);
 
                if (!exist) {
-                       ok = imap_cmd_create(SESSION(session)->sock, imap_path);
+                       ok = imap_cmd_create(session, imap_path);
                        if (ok != IMAP_SUCCESS) {
                                log_warning(_("can't create mailbox\n"));
                                g_free(imap_path);
@@ -1302,7 +1389,7 @@ gint imap_rename_folder(Folder *folder, FolderItem *item, const gchar *name)
 
        g_free(session->mbox);
        session->mbox = NULL;
-       ok = imap_cmd_examine(SESSION(session)->sock, "INBOX",
+       ok = imap_cmd_examine(session, "INBOX",
                              &exists, &recent, &unseen, &uid_validity);
        if (ok != IMAP_SUCCESS) {
                g_free(real_oldpath);
@@ -1320,7 +1407,7 @@ gint imap_rename_folder(Folder *folder, FolderItem *item, const gchar *name)
        real_newpath = imap_locale_to_modified_utf7(newpath);
        imap_path_separator_subst(real_newpath, separator);
 
-       ok = imap_cmd_rename(SESSION(session)->sock, real_oldpath, real_newpath);
+       ok = imap_cmd_rename(session, real_oldpath, real_newpath);
        if (ok != IMAP_SUCCESS) {
                log_warning(_("can't rename mailbox: %s to %s\n"),
                            real_oldpath, real_newpath);
@@ -1377,14 +1464,14 @@ gint imap_remove_folder(Folder *folder, FolderItem *item)
 
        path = imap_get_real_path(IMAP_FOLDER(folder), item->path);
 
-       ok = imap_cmd_examine(SESSION(session)->sock, "INBOX",
+       ok = imap_cmd_examine(session, "INBOX",
                              &exists, &recent, &unseen, &uid_validity);
        if (ok != IMAP_SUCCESS) {
                g_free(path);
                return -1;
        }
 
-       ok = imap_cmd_delete(SESSION(session)->sock, path);
+       ok = imap_cmd_delete(session, path);
        if (ok != IMAP_SUCCESS) {
                log_warning(_("can't delete mailbox\n"));
                g_free(path);
@@ -1416,7 +1503,7 @@ static GSList *imap_get_uncached_messages(IMAPSession *session,
        g_return_val_if_fail(item->folder != NULL, NULL);
        g_return_val_if_fail(FOLDER_CLASS(item->folder) == &imap_class, NULL);
 
-       if (imap_cmd_envelope(SESSION(session)->sock, numberlist_to_imapset(numlist))
+       if (imap_cmd_envelope(session, numberlist_to_imapset(numlist))
            != IMAP_SUCCESS) {
                log_warning(_("can't get envelope\n"));
                return NULL;
@@ -1536,10 +1623,8 @@ static SockInfo *imap_open(const gchar *server, gushort port)
                sock_close(sock);
                return NULL;
        }
-       return imap_init_sock(sock, ssl_type);
-#else
-       return imap_init_sock(sock);
 #endif
+       return sock;
 }
 
 #if USE_OPENSSL
@@ -1548,23 +1633,6 @@ static SockInfo *imap_init_sock(SockInfo *sock, SSLType ssl_type)
 static SockInfo *imap_init_sock(SockInfo *sock)
 #endif
 {
-       imap_cmd_count = 0;
-#if USE_OPENSSL
-       if (ssl_type == SSL_STARTTLS) {
-               gint ok;
-
-               ok = imap_cmd_starttls(sock);
-               if (ok != IMAP_SUCCESS) {
-                       log_warning(_("Can't start TLS session.\n"));
-                       sock_close(sock);
-                       return NULL;
-               }
-               if (!ssl_init_socket_with_method(sock, SSL_METHOD_TLSv1)) {
-                       sock_close(sock);
-                       return NULL;
-               }
-       }
-#endif
 
        return sock;
 }
@@ -1638,7 +1706,7 @@ static void imap_parse_namespace(IMAPSession *session, IMAPFolder *folder)
                return;
        }
        
-       if (imap_cmd_namespace(SESSION(session)->sock, &ns_str)
+       if (imap_cmd_namespace(session, &ns_str)
            != IMAP_SUCCESS) {
                log_warning(_("can't get namespace\n"));
                return;
@@ -1674,7 +1742,7 @@ static void imap_get_namespace_by_list(IMAPSession *session, IMAPFolder *folder)
            folder->ns_shared   != NULL)
                return;
 
-       imap_cmd_gen_send(SESSION(session)->sock, "LIST \"\" \"\"");
+       imap_gen_send(session, "LIST \"\" \"\"");
        item_list = imap_parse_list(NULL, session, "", &separator);
        for (cur = item_list; cur != NULL; cur = cur->next)
                folder_item_destroy(FOLDER_ITEM(cur->data));
@@ -1791,6 +1859,7 @@ static gchar *imap_parse_atom(SockInfo *sock, gchar *src,
 
                cur_pos = strchr_cpy(cur_pos + 1, '}', buf, sizeof(buf));
                len = atoi(buf);
+               g_return_val_if_fail(len > 0, cur_pos);
 
                g_string_truncate(str, 0);
                cur_pos = str->str;
@@ -1833,6 +1902,7 @@ static gchar *imap_get_header(SockInfo *sock, gchar *cur_pos, gchar **headers,
 
        cur_pos = strchr_cpy(cur_pos + 1, '}', buf, sizeof(buf));
        len = atoi(buf);
+       g_return_val_if_fail(len > 0, cur_pos);
 
        g_string_truncate(str, 0);
        cur_pos = str->str;
@@ -2016,7 +2086,7 @@ static gint imap_set_message_flags(IMAPSession *session,
 
        g_string_append_c(buf, ')');
 
-       ok = imap_cmd_store(SESSION(session)->sock, numberlist_to_imapset(numlist),
+       ok = imap_cmd_store(session, numberlist_to_imapset(numlist),
                            buf->str);
        g_string_free(buf, TRUE);
 
@@ -2045,7 +2115,7 @@ static gint imap_select(IMAPSession *session, IMAPFolder *folder,
        session->mbox = NULL;
 
        real_path = imap_get_real_path(folder, path);
-       ok = imap_cmd_select(SESSION(session)->sock, real_path,
+       ok = imap_cmd_select(session, real_path,
                             exists, recent, unseen, uid_validity);
        if (ok != IMAP_SUCCESS)
                log_warning(_("can't select folder: %s\n"), real_path);
@@ -2076,11 +2146,11 @@ static gint imap_status(IMAPSession *session, IMAPFolder *folder,
 
        real_path = imap_get_real_path(folder, path);
        QUOTE_IF_REQUIRED(real_path_, real_path);
-       imap_cmd_gen_send(SESSION(session)->sock, "STATUS %s "
-                         "(MESSAGES RECENT UIDNEXT UIDVALIDITY UNSEEN)",
-                         real_path_);
+       imap_gen_send(session, "STATUS %s "
+                     "(MESSAGES RECENT UIDNEXT UIDVALIDITY UNSEEN)",
+                     real_path_);
 
-       ok = imap_cmd_ok(SESSION(session)->sock, argbuf);
+       ok = imap_cmd_ok(session, argbuf);
        if (ok != IMAP_SUCCESS) THROW(ok);
 
        str = search_array_str(argbuf, "STATUS");
@@ -2126,7 +2196,7 @@ catch:
 
 /* low-level IMAP4rev1 commands */
 
-static gint imap_cmd_login(SockInfo *sock,
+static gint imap_cmd_login(IMAPSession *session,
                           const gchar *user, const gchar *pass)
 {
        gchar *user_, *pass_;
@@ -2134,57 +2204,40 @@ static gint imap_cmd_login(SockInfo *sock,
 
        QUOTE_IF_REQUIRED(user_, user);
        QUOTE_IF_REQUIRED(pass_, pass);
-       imap_cmd_gen_send(sock, "LOGIN %s %s", user_, pass_);
+       imap_gen_send(session, "LOGIN %s %s", user_, pass_);
 
-       ok = imap_cmd_ok(sock, NULL);
+       ok = imap_cmd_ok(session, NULL);
        if (ok != IMAP_SUCCESS)
                log_warning(_("IMAP4 login failed.\n"));
 
        return ok;
 }
 
-static gint imap_cmd_logout(SockInfo *sock)
-{
-       imap_cmd_gen_send(sock, "LOGOUT");
-       return imap_cmd_ok(sock, NULL);
-}
-
-/* Send a NOOP, and examine the server's response to see whether this
- * connection is pre-authenticated or not. */
-static gint imap_greeting(SockInfo *sock, gboolean *is_preauth)
+static gint imap_cmd_logout(IMAPSession *session)
 {
-       GPtrArray *argbuf;
-       gint r;
-
-       imap_cmd_gen_send(sock, "NOOP");
-       argbuf = g_ptr_array_new(); /* will hold messages sent back */
-       r = imap_cmd_ok(sock, argbuf);
-       *is_preauth = search_array_str(argbuf, "PREAUTH") != NULL;
-
-       ptr_array_free_strings(argbuf);
-       g_ptr_array_free(argbuf, TRUE);
-       
-       return r;
+       imap_gen_send(session, "LOGOUT");
+       return imap_cmd_ok(session, NULL);
 }
 
-static void imap_get_capability(Session *session)
+/* Send CAPABILITY, and examine the server's response to see whether this
+ * connection is pre-authenticated or not and build a list of CAPABILITIES. */
+static gint imap_greeting(IMAPSession *session)
 {
        gchar *capstr;
        GPtrArray *argbuf;
 
-       if (IMAP_SESSION(session)->capability != NULL)
-               return;
-
-       imap_cmd_gen_send(session->sock, "CAPABILITY");
+       imap_gen_send(session, "CAPABILITY");
        
        argbuf = g_ptr_array_new();
 
-       if (imap_cmd_ok(session->sock, argbuf) != IMAP_SUCCESS ||
+       if (imap_cmd_ok(session, argbuf) != IMAP_SUCCESS ||
            ((capstr = search_array_str(argbuf, "CAPABILITY ")) == NULL)) {
                ptr_array_free_strings(argbuf);
                g_ptr_array_free(argbuf, TRUE);
-               return;
+               return -1;
        }
+
+       session->authenticated = search_array_str(argbuf, "PREAUTH") != NULL;
        
        capstr += strlen("CAPABILITY ");
 
@@ -2192,6 +2245,8 @@ static void imap_get_capability(Session *session)
        
        ptr_array_free_strings(argbuf);
        g_ptr_array_free(argbuf, TRUE);
+
+       return 0;
 }
 
 static gboolean imap_has_capability(IMAPSession *session, const gchar *cap)
@@ -2205,6 +2260,12 @@ static gboolean imap_has_capability(IMAPSession *session, const gchar *cap)
        return FALSE;
 }
 
+void imap_free_capabilities(IMAPSession *session)
+{
+       g_strfreev(session->capability);
+       session->capability = NULL;
+}
+
 static const IMAPSet numberlist_to_imapset(MsgNumberList *list)
 {
        static GString *imapset = NULL;
@@ -2247,21 +2308,21 @@ static const IMAPSet numberlist_to_imapset(MsgNumberList *list)
        return imapset->str;
 }
 
-static gint imap_cmd_noop(SockInfo *sock)
+static gint imap_cmd_noop(IMAPSession *session)
 {
-       imap_cmd_gen_send(sock, "NOOP");
-       return imap_cmd_ok(sock, NULL);
+       imap_gen_send(session, "NOOP");
+       return imap_cmd_ok(session, NULL);
 }
 
-static gint imap_cmd_starttls(SockInfo *sock)
+static gint imap_cmd_starttls(IMAPSession *session)
 {
-       imap_cmd_gen_send(sock, "STARTTLS");
-       return imap_cmd_ok(sock, NULL);
+       imap_gen_send(session, "STARTTLS");
+       return imap_cmd_ok(session, NULL);
 }
 
 #define THROW(err) { ok = err; goto catch; }
 
-static gint imap_cmd_namespace(SockInfo *sock, gchar **ns_str)
+static gint imap_cmd_namespace(IMAPSession *session, gchar **ns_str)
 {
        gint ok;
        GPtrArray *argbuf;
@@ -2269,8 +2330,8 @@ static gint imap_cmd_namespace(SockInfo *sock, gchar **ns_str)
 
        argbuf = g_ptr_array_new();
 
-       imap_cmd_gen_send(sock, "NAMESPACE");
-       if ((ok = imap_cmd_ok(sock, argbuf)) != IMAP_SUCCESS) THROW(ok);
+       imap_gen_send(session, "NAMESPACE");
+       if ((ok = imap_cmd_ok(session, argbuf)) != IMAP_SUCCESS) THROW(ok);
 
        str = search_array_str(argbuf, "NAMESPACE");
        if (!str) THROW(IMAP_ERROR);
@@ -2286,7 +2347,7 @@ catch:
 
 #undef THROW
 
-static gint imap_cmd_list(SockInfo *sock, const gchar *ref,
+static gint imap_cmd_list(IMAPSession *session, const gchar *ref,
                          const gchar *mailbox, GPtrArray *argbuf)
 {
        gchar *ref_, *mailbox_;
@@ -2296,14 +2357,14 @@ static gint imap_cmd_list(SockInfo *sock, const gchar *ref,
 
        QUOTE_IF_REQUIRED(ref_, ref);
        QUOTE_IF_REQUIRED(mailbox_, mailbox);
-       imap_cmd_gen_send(sock, "LIST %s %s", ref_, mailbox_);
+       imap_gen_send(session, "LIST %s %s", ref_, mailbox_);
 
-       return imap_cmd_ok(sock, argbuf);
+       return imap_cmd_ok(session, argbuf);
 }
 
 #define THROW goto catch
 
-static gint imap_cmd_do_select(SockInfo *sock, const gchar *folder,
+static gint imap_cmd_do_select(IMAPSession *session, const gchar *folder,
                               gboolean examine,
                               gint *exists, gint *recent, gint *unseen,
                               guint32 *uid_validity)
@@ -2323,9 +2384,9 @@ static gint imap_cmd_do_select(SockInfo *sock, const gchar *folder,
                select_cmd = "SELECT";
 
        QUOTE_IF_REQUIRED(folder_, folder);
-       imap_cmd_gen_send(sock, "%s %s", select_cmd, folder_);
+       imap_gen_send(session, "%s %s", select_cmd, folder_);
 
-       if ((ok = imap_cmd_ok(sock, argbuf)) != IMAP_SUCCESS) THROW;
+       if ((ok = imap_cmd_ok(session, argbuf)) != IMAP_SUCCESS) THROW;
 
        resp_str = search_array_contain_str(argbuf, "EXISTS");
        if (resp_str) {
@@ -2367,57 +2428,57 @@ catch:
        return ok;
 }
 
-static gint imap_cmd_select(SockInfo *sock, const gchar *folder,
+static gint imap_cmd_select(IMAPSession *session, const gchar *folder,
                            gint *exists, gint *recent, gint *unseen,
                            guint32 *uid_validity)
 {
-       return imap_cmd_do_select(sock, folder, FALSE,
+       return imap_cmd_do_select(session, folder, FALSE,
                                  exists, recent, unseen, uid_validity);
 }
 
-static gint imap_cmd_examine(SockInfo *sock, const gchar *folder,
+static gint imap_cmd_examine(IMAPSession *session, const gchar *folder,
                             gint *exists, gint *recent, gint *unseen,
                             guint32 *uid_validity)
 {
-       return imap_cmd_do_select(sock, folder, TRUE,
+       return imap_cmd_do_select(session, folder, TRUE,
                                  exists, recent, unseen, uid_validity);
 }
 
 #undef THROW
 
-static gint imap_cmd_create(SockInfo *sock, const gchar *folder)
+static gint imap_cmd_create(IMAPSession *session, const gchar *folder)
 {
        gchar *folder_;
 
        QUOTE_IF_REQUIRED(folder_, folder);
-       imap_cmd_gen_send(sock, "CREATE %s", folder_);
+       imap_gen_send(session, "CREATE %s", folder_);
 
-       return imap_cmd_ok(sock, NULL);
+       return imap_cmd_ok(session, NULL);
 }
 
-static gint imap_cmd_rename(SockInfo *sock, const gchar *old_folder,
+static gint imap_cmd_rename(IMAPSession *session, const gchar *old_folder,
                            const gchar *new_folder)
 {
        gchar *old_folder_, *new_folder_;
 
        QUOTE_IF_REQUIRED(old_folder_, old_folder);
        QUOTE_IF_REQUIRED(new_folder_, new_folder);
-       imap_cmd_gen_send(sock, "RENAME %s %s", old_folder_, new_folder_);
+       imap_gen_send(session, "RENAME %s %s", old_folder_, new_folder_);
 
-       return imap_cmd_ok(sock, NULL);
+       return imap_cmd_ok(session, NULL);
 }
 
-static gint imap_cmd_delete(SockInfo *sock, const gchar *folder)
+static gint imap_cmd_delete(IMAPSession *session, const gchar *folder)
 {
        gchar *folder_;
 
        QUOTE_IF_REQUIRED(folder_, folder);
-       imap_cmd_gen_send(sock, "DELETE %s", folder_);
+       imap_gen_send(session, "DELETE %s", folder_);
 
-       return imap_cmd_ok(sock, NULL);
+       return imap_cmd_ok(session, NULL);
 }
 
-static gint imap_cmd_search(SockInfo *sock, const gchar *criteria, GSList **list)
+static gint imap_cmd_search(IMAPSession *session, const gchar *criteria, GSList **list)
 {
        gint ok;
        gchar *uidlist;
@@ -2429,9 +2490,9 @@ static gint imap_cmd_search(SockInfo *sock, const gchar *criteria, GSList **list
        *list = NULL;
        
        argbuf = g_ptr_array_new();
-       imap_cmd_gen_send(sock, "UID SEARCH %s", criteria);
+       imap_gen_send(session, "UID SEARCH %s", criteria);
 
-       ok = imap_cmd_ok(sock, argbuf);
+       ok = imap_cmd_ok(session, argbuf);
        if (ok != IMAP_SUCCESS) {
                ptr_array_free_strings(argbuf);
                g_ptr_array_free(argbuf, TRUE);
@@ -2456,7 +2517,7 @@ static gint imap_cmd_search(SockInfo *sock, const gchar *criteria, GSList **list
        return IMAP_SUCCESS;
 }
 
-static gint imap_cmd_fetch(SockInfo *sock, guint32 uid, const gchar *filename)
+static gint imap_cmd_fetch(IMAPSession *session, guint32 uid, const gchar *filename)
 {
        gint ok;
        gchar *buf;
@@ -2466,9 +2527,9 @@ static gint imap_cmd_fetch(SockInfo *sock, guint32 uid, const gchar *filename)
 
        g_return_val_if_fail(filename != NULL, IMAP_ERROR);
 
-       imap_cmd_gen_send(sock, "UID FETCH %d BODY.PEEK[]", uid);
+       imap_gen_send(session, "UID FETCH %d BODY.PEEK[]", uid);
 
-       while ((ok = imap_cmd_gen_recv(sock, &buf))
+       while ((ok = imap_gen_recv(session, &buf))
               == IMAP_SUCCESS) {
                if (buf[0] != '*' || buf[1] != ' ') {
                        g_free(buf);
@@ -2491,18 +2552,19 @@ static gint imap_cmd_fetch(SockInfo *sock, guint32 uid, const gchar *filename)
                return IMAP_ERROR;
        }
        size_num = atol(size_str);
+       g_return_val_if_fail(size_num > 0, IMAP_ERROR);
 
        if (*cur_pos != '\0') {
                g_free(buf);
                return IMAP_ERROR;
        }
 
-       if (recv_bytes_write_to_file(sock, size_num, filename) != 0) {
+       if (recv_bytes_write_to_file(SESSION(session)->sock, size_num, filename) != 0) {
                g_free(buf);
                return IMAP_ERROR;
        }
 
-       if (imap_cmd_gen_recv(sock, &buf) != IMAP_SUCCESS) {
+       if (imap_gen_recv(session, &buf) != IMAP_SUCCESS) {
                g_free(buf);
                return IMAP_ERROR;
        }
@@ -2513,7 +2575,7 @@ static gint imap_cmd_fetch(SockInfo *sock, guint32 uid, const gchar *filename)
        }
 
        g_free(buf);
-       ok = imap_cmd_ok(sock, NULL);
+       ok = imap_cmd_ok(session, NULL);
 
        return ok;
 }
@@ -2537,9 +2599,9 @@ static gint imap_cmd_append(IMAPSession *session, const gchar *destfolder,
                return -1;
        }
        QUOTE_IF_REQUIRED(destfolder_, destfolder);
-       imap_cmd_gen_send(SESSION(session)->sock, "APPEND %s (\\Seen) {%d}", destfolder_, size);
+       imap_gen_send(session, "APPEND %s (\\Seen) {%d}", destfolder_, size);
 
-       ok = imap_cmd_gen_recv(SESSION(session)->sock, &imapbuf);
+       ok = imap_gen_recv(session, &imapbuf);
        if (ok != IMAP_SUCCESS || imapbuf[0] != '+' || imapbuf[1] != ' ') {
                log_warning(_("can't append %s to %s\n"), file, destfolder_);
                g_free(imapbuf);
@@ -2571,7 +2633,7 @@ static gint imap_cmd_append(IMAPSession *session, const gchar *destfolder,
        reply = g_ptr_array_new();
 
        *new_uid = 0;
-       ok = imap_cmd_ok(SESSION(session)->sock, reply);
+       ok = imap_cmd_ok(session, reply);
        if (ok != IMAP_SUCCESS)
                log_warning(_("can't append message to %s\n"), destfolder_);
        else if (
@@ -2603,12 +2665,12 @@ static gint imap_cmd_copy(IMAPSession * session,
        g_return_val_if_fail(new_uid != NULL, IMAP_ERROR);
 
        QUOTE_IF_REQUIRED(destfolder_, destfolder);
-       imap_cmd_gen_send(SESSION(session)->sock, "UID COPY %d %s", msgnum, destfolder_);
+       imap_gen_send(session, "UID COPY %d %s", msgnum, destfolder_);
 
        reply = g_ptr_array_new();
 
        *new_uid = 0;
-       ok = imap_cmd_ok(SESSION(session)->sock, reply);
+       ok = imap_cmd_ok(session, reply);
        if (ok != IMAP_SUCCESS)
                log_warning(_("can't copy %d to %s\n"), msgnum, destfolder_);
        else if (imap_has_capability(session, "UIDPLUS") && reply->len > 0)
@@ -2622,7 +2684,7 @@ static gint imap_cmd_copy(IMAPSession * session,
        return ok;
 }
 
-gint imap_cmd_envelope(SockInfo *sock, IMAPSet set)
+gint imap_cmd_envelope(IMAPSession *session, IMAPSet set)
 {
        static GString *header_fields = NULL;
 
@@ -2651,23 +2713,23 @@ gint imap_cmd_envelope(SockInfo *sock, IMAPSet set)
                                        namelen, elem->name);
                }
        }
-       
-       imap_cmd_gen_send
-               (sock, "UID FETCH %s (UID FLAGS RFC822.SIZE BODY.PEEK[HEADER.FIELDS (%s)])",
+
+       imap_gen_send
+               (session, "UID FETCH %s (UID FLAGS RFC822.SIZE BODY.PEEK[HEADER.FIELDS (%s)])",
                 set, header_fields->str);
 
        return IMAP_SUCCESS;
 }
 
-static gint imap_cmd_store(SockInfo *sock, IMAPSet set,
+static gint imap_cmd_store(IMAPSession *session, IMAPSet set,
                           gchar *sub_cmd)
 {
        gint ok;
 
-       imap_cmd_gen_send(sock, "UID STORE %s %s",
+       imap_gen_send(session, "UID STORE %s %s",
                          set, sub_cmd);
 
-       if ((ok = imap_cmd_ok(sock, NULL)) != IMAP_SUCCESS) {
+       if ((ok = imap_cmd_ok(session, NULL)) != IMAP_SUCCESS) {
                log_warning(_("error while imap command: STORE %s %s\n"),
                            set, sub_cmd);
                return ok;
@@ -2676,12 +2738,12 @@ static gint imap_cmd_store(SockInfo *sock, IMAPSet set,
        return IMAP_SUCCESS;
 }
 
-static gint imap_cmd_expunge(SockInfo *sock)
+static gint imap_cmd_expunge(IMAPSession *session)
 {
        gint ok;
 
-       imap_cmd_gen_send(sock, "EXPUNGE");
-       if ((ok = imap_cmd_ok(sock, NULL)) != IMAP_SUCCESS) {
+       imap_gen_send(session, "EXPUNGE");
+       if ((ok = imap_cmd_ok(session, NULL)) != IMAP_SUCCESS) {
                log_warning(_("error while imap command: EXPUNGE\n"));
                return ok;
        }
@@ -2689,14 +2751,14 @@ static gint imap_cmd_expunge(SockInfo *sock)
        return IMAP_SUCCESS;
 }
 
-static gint imap_cmd_ok(SockInfo *sock, GPtrArray *argbuf)
+static gint imap_cmd_ok(IMAPSession *session, GPtrArray *argbuf)
 {
        gint ok;
        gchar *buf;
        gint cmd_num;
        gchar cmd_status[IMAPBUFSIZE];
 
-       while ((ok = imap_cmd_gen_recv(sock, &buf))
+       while ((ok = imap_gen_recv(session, &buf))
               == IMAP_SUCCESS) {
                if (buf[0] == '*' && buf[1] == ' ') {
                        if (argbuf)
@@ -2704,9 +2766,10 @@ static gint imap_cmd_ok(SockInfo *sock, GPtrArray *argbuf)
                        continue;
                }
 
-               if (sscanf(buf, "%d %s", &cmd_num, cmd_status) < 2)
+               if (sscanf(buf, "%d %s", &cmd_num, cmd_status) < 2) {
+                       g_free(buf);
                        return IMAP_ERROR;
-               else if (cmd_num == imap_cmd_count &&
+               } else if (cmd_num == session->cmd_count &&
                         !strcmp(cmd_status, "OK")) {
                        if (argbuf)
                                g_ptr_array_add(argbuf, g_strdup(buf));
@@ -2722,7 +2785,7 @@ static gint imap_cmd_ok(SockInfo *sock, GPtrArray *argbuf)
        return ok;
 }
 
-static void imap_cmd_gen_send(SockInfo *sock, const gchar *format, ...)
+static void imap_gen_send(IMAPSession *session, const gchar *format, ...)
 {
        gchar buf[IMAPBUFSIZE];
        gchar tmp[IMAPBUFSIZE];
@@ -2733,21 +2796,21 @@ static void imap_cmd_gen_send(SockInfo *sock, const gchar *format, ...)
        g_vsnprintf(tmp, sizeof(tmp), format, args);
        va_end(args);
 
-       imap_cmd_count++;
+       session->cmd_count++;
 
-       g_snprintf(buf, sizeof(buf), "%d %s\r\n", imap_cmd_count, tmp);
+       g_snprintf(buf, sizeof(buf), "%d %s\r\n", session->cmd_count, tmp);
        if (!strncasecmp(tmp, "LOGIN ", 6) && (p = strchr(tmp + 6, ' '))) {
                *p = '\0';
-               log_print("IMAP4> %d %s ********\n", imap_cmd_count, tmp);
+               log_print("IMAP4> %d %s ********\n", session->cmd_count, tmp);
        } else
-               log_print("IMAP4> %d %s\n", imap_cmd_count, tmp);
+               log_print("IMAP4> %d %s\n", session->cmd_count, tmp);
 
-       sock_write_all(sock, buf, strlen(buf));
+       sock_write_all(SESSION(session)->sock, buf, strlen(buf));
 }
 
-static gint imap_cmd_gen_recv(SockInfo *sock, gchar **buf)
+static gint imap_gen_recv(IMAPSession *session, gchar **buf)
 {
-       if ((*buf = sock_getline(sock)) == NULL)
+       if ((*buf = sock_getline(SESSION(session)->sock)) == NULL)
                return IMAP_SOCKET;
 
        strretchomp(*buf);
@@ -3064,7 +3127,7 @@ static gint get_list_of_uids(Folder *folder, IMAPFolderItem *item, GSList **msgn
                return -1;
 
        cmd_buf = g_strdup_printf("UID %d:*", item->lastuid + 1);
-       ok = imap_cmd_search(SESSION(session)->sock, cmd_buf, &uidlist);
+       ok = imap_cmd_search(session, cmd_buf, &uidlist);
        g_free(cmd_buf);
 
        if (ok == IMAP_SOCKET) {
@@ -3080,9 +3143,9 @@ static gint get_list_of_uids(Folder *folder, IMAPFolderItem *item, GSList **msgn
                argbuf = g_ptr_array_new();
 
                cmd_buf = g_strdup_printf("UID FETCH %d:* (UID)", item->lastuid + 1);
-               imap_cmd_gen_send(SESSION(session)->sock, cmd_buf);
+               imap_gen_send(session, cmd_buf);
                g_free(cmd_buf);
-               ok = imap_cmd_ok(SESSION(session)->sock, argbuf);
+               ok = imap_cmd_ok(session, argbuf);
                if (ok != IMAP_SUCCESS) {
                        ptr_array_free_strings(argbuf);
                        g_ptr_array_free(argbuf, TRUE);