path: root/camel/providers/pop3/camel-pop3-store.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-pop3-store.c : class for a pop3 store */

/* 
 * Authors:
 *   Dan Winship <danw@helixcode.com>
 *
 * Copyright (C) 2000 Helix Code, Inc. (www.helixcode.com)
 *
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License as 
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#define d(x)

#include "config.h"

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#include "camel-pop3-store.h"
#include "camel-pop3-folder.h"
#include "camel-stream-buffer.h"
#include "camel-stream-fs.h"
#include "camel-session.h"
#include "camel-exception.h"
#include "camel-url.h"
#include "md5-utils.h"

/* Specified in RFC 1939 */
#define POP3_PORT 110

#ifdef HAVE_KRB4
/* Specified nowhere */
#define KPOP_PORT 1109

#include <krb.h>
#endif

static CamelServiceClass *service_class = NULL;

static void finalize (CamelObject *object);

static gboolean pop3_connect (CamelService *service, CamelException *ex);
static gboolean pop3_disconnect (CamelService *service, CamelException *ex);
static GList *query_auth_types (CamelService *service, CamelException *ex);
static void free_auth_types (CamelService *service, GList *authtypes);
static char *get_name (CamelService *service, gboolean brief);

static CamelFolder *get_folder (CamelStore *store, const char *folder_name, 
                gboolean create, CamelException *ex);
static char *get_folder_name (CamelStore *store, const char *folder_name, 
                  CamelException *ex);
static char *get_root_folder_name (CamelStore *store, CamelException *ex);

static int pop3_get_response (CamelPop3Store *store, char **ret);


static void
camel_pop3_store_class_init (CamelPop3StoreClass *camel_pop3_store_class)
{
    CamelServiceClass *camel_service_class =
        CAMEL_SERVICE_CLASS (camel_pop3_store_class);
    CamelStoreClass *camel_store_class =
        CAMEL_STORE_CLASS (camel_pop3_store_class);
    
    service_class = CAMEL_SERVICE_CLASS(camel_type_get_global_classfuncs (camel_service_get_type ()));

    /* virtual method overload */
    camel_service_class->connect = pop3_connect;
    camel_service_class->disconnect = pop3_disconnect;
    camel_service_class->query_auth_types = query_auth_types;
    camel_service_class->free_auth_types = free_auth_types;
    camel_service_class->get_name = get_name;

    camel_store_class->get_folder = get_folder;
    camel_store_class->get_folder_name = get_folder_name;
    camel_store_class->get_root_folder_name = get_root_folder_name;
}



static void
camel_pop3_store_init (gpointer object, gpointer klass)
{
    CamelService *service = CAMEL_SERVICE (object);

    service->url_flags = (CAMEL_SERVICE_URL_NEED_USER | CAMEL_SERVICE_URL_NEED_HOST);
}

CamelType
camel_pop3_store_get_type (void)
{
    static CamelType camel_pop3_store_type = CAMEL_INVALID_TYPE;

    if (!camel_pop3_store_type) {
        camel_pop3_store_type = camel_type_register (CAMEL_STORE_TYPE, "CamelPop3Store",
                                 sizeof (CamelPop3Store),
                                 sizeof (CamelPop3StoreClass),
                                 (CamelObjectClassInitFunc) camel_pop3_store_class_init,
                                 NULL,
                                 (CamelObjectInitFunc) camel_pop3_store_init,
                                 finalize);
    }

    return camel_pop3_store_type;
}

static void
finalize (CamelObject *object)
{
    CamelPop3Store *pop3_store = CAMEL_POP3_STORE (object);
    CamelException ex;

    camel_exception_init (&ex);
    pop3_disconnect (CAMEL_SERVICE (object), &ex);
    camel_exception_clear (&ex);

    if (pop3_store->apop_timestamp)
        g_free (pop3_store->apop_timestamp);
}

static CamelServiceAuthType password_authtype = {
    "Password",

    "This option will connect to the POP server using a plaintext "
    "password. This is the only option supported by many POP servers.",

    "",
    TRUE
};

static CamelServiceAuthType apop_authtype = {
    "APOP",

    "This option will connect to the POP server using an encrypted "
    "password via the APOP protocol. This may not work for all users "
    "even on servers that claim to support it.",

    "+APOP",
    TRUE
};

#ifdef HAVE_KRB4
static CamelServiceAuthType kpop_authtype = {
    "Kerberos 4 (KPOP)",

    "This will connect to the POP server and use Kerberos 4 "
    "to authenticate to it.",

    "+KPOP",
    FALSE
};
#endif

static gboolean
connect_to_server (CamelService *service, gboolean real, CamelException *ex)
{
    CamelPop3Store *store = CAMEL_POP3_STORE (service);
    struct hostent *h;
    struct sockaddr_in sin;
    int fd, status;
    char *buf, *apoptime, *apopend;
#ifdef HAVE_KRB4
    gboolean kpop = (service->url->port == KPOP_PORT);
#endif

    h = camel_service_gethost (service, ex);
    if (!h)
        return FALSE;

    sin.sin_family = h->h_addrtype;
    if (service->url->port)
        sin.sin_port = htons (service->url->port);
    else
        sin.sin_port = htons (POP3_PORT);
    memcpy (&sin.sin_addr, h->h_addr, sizeof (sin.sin_addr));

    fd = socket (h->h_addrtype, SOCK_STREAM, 0);
    if (fd == -1 ||
        connect (fd, (struct sockaddr *)&sin, sizeof(sin)) == -1) {
        if (real) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                          "Could not connect to %s: %s",
                          h->h_name, g_strerror(errno));
        }
        if (fd > -1)
            close (fd);
        return FALSE;
    }

#ifdef HAVE_KRB4
    if (kpop) {
        KTEXT_ST ticket_st;
        MSG_DAT msg_data;
        CREDENTIALS cred;
        Key_schedule schedule;
        char *hostname;

        /* Need to copy hostname, because krb_realmofhost will
         * call gethostbyname as well, and gethostbyname uses
         * static storage.
         */
        hostname = g_strdup (h->h_name);
        status = krb_sendauth (0, fd, &ticket_st, "pop", hostname,
                       krb_realmofhost (hostname), 0,
                       &msg_data, &cred, schedule,
                       NULL, NULL, "KPOPV0.1");
        g_free (hostname);
        if (status != KSUCCESS) {
            if (real) {
                camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                              "Could not authenticate "
                              "to KPOP server: %s",
                              krb_err_txt[status]);
            }
            close (fd);
            return FALSE;
        }

        if (!service->url->passwd)
            service->url->passwd = g_strdup (service->url->user);
    }
#endif /* HAVE_KRB4 */

    store->ostream = camel_stream_fs_new_with_fd (fd);
    store->istream = camel_stream_buffer_new (store->ostream,
                          CAMEL_STREAM_BUFFER_READ);

    /* Read the greeting, check status */
    status = pop3_get_response (store, &buf);
    if (status != CAMEL_POP3_OK) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                      "%s: %s", status == CAMEL_POP3_ERR ?
                      "Error connecting to POP server" :
                      "Error reading greeting from POP server",
                      buf);
        g_free (buf);
        pop3_disconnect (service, ex);
        return FALSE;
    }

    apoptime = strchr (buf, '<');
    apopend = apoptime ? strchr (apoptime, '>') : NULL;
    if (apopend) {
        store->apop_timestamp = g_strndup (apoptime,
                           apopend - apoptime + 1);
        memmove (apoptime, apopend + 1, strlen (apopend + 1));
    }
    store->implementation = buf;

    /* Check extensions */
    store->login_delay = -1;
    store->supports_top = -1;
    store->supports_uidl = -1;
    store->expires = -1;

    status = camel_pop3_command (store, NULL, "CAPA");
    if (status == CAMEL_POP3_OK) {
        char *p;
        int len;

        buf = camel_pop3_command_get_additional_data (store, ex);
        if (camel_exception_is_set (ex)) {
            pop3_disconnect (service, ex);
            return FALSE;
        }

        p = buf;
        while (*p) {
            len = strcspn (p, "\n");
            if (!strncmp (p, "IMPLEMENTATION ", 15)) {
                g_free (store->implementation);
                store->implementation =
                    g_strndup (p + 15, len - 15);
            } else if (len == 3 && !strncmp (p, "TOP", 3))
                store->supports_top = TRUE;
            else if (len == 4 && !strncmp (p, "UIDL", 4))
                store->supports_uidl = TRUE;
            else if (!strncmp (p, "LOGIN-DELAY ", 12))
                store->login_delay = atoi (p + 12);
            else if (!strncmp (p, "EXPIRE NEVER", 12))
                store->expires = FALSE;
            else if (!strncmp (p, "EXPIRE ", 7))
                store->expires = TRUE;

            p += len;
            if (*p)
                p++;
        }

        g_free (buf);
    }

    return TRUE;
}

static GList *
query_auth_types (CamelService *service, CamelException *ex)
{
    CamelPop3Store *store = CAMEL_POP3_STORE (service);
    GList *ret = NULL;
    gboolean passwd = TRUE, apop = TRUE;
#ifdef HAVE_KRB4
    gboolean kpop = TRUE;
    int saved_port;
#endif

    if (service->url && !service->url->empty) {
        passwd = connect_to_server (service, FALSE, ex);
        if (camel_exception_get_id (ex) != CAMEL_EXCEPTION_NONE)
            return NULL;
        apop = store->apop_timestamp != NULL;
        if (passwd)
            pop3_disconnect (service, ex);
#ifdef HAVE_KRB4
        saved_port = service->url->port;
        service->url->port = KPOP_PORT;
        kpop = connect_to_server (service, FALSE, ex);
        service->url->port = saved_port;
        if (camel_exception_get_id (ex) != CAMEL_EXCEPTION_NONE)
            return NULL;
        if (kpop)
            pop3_disconnect (service, ex);
#endif
    }

    if (passwd)
        ret = g_list_append (ret, &password_authtype);
    if (apop)
        ret = g_list_append (ret, &apop_authtype);
#ifdef HAVE_KRB4
    if (kpop)
        ret = g_list_append (ret, &kpop_authtype);
#endif

    if (!ret) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                      "Could not connect to POP server on "
                      "%s.", service->url->host);
    }                     

    return ret;
}

static void
free_auth_types (CamelService *service, GList *authtypes)
{
    g_list_free (authtypes);
}

static char *
get_name (CamelService *service, gboolean brief)
{
    if (brief)
        return g_strdup_printf ("POP server %s", service->url->host);
    else {
        return g_strdup_printf ("POP service for %s on %s",
                    service->url->user,
                    service->url->host);
    }
}


/**
 * camel_pop3_store_expunge:
 * @store: the store
 * @ex: a CamelException
 *
 * Expunge messages from the store. This will result in the connection
 * being closed, which may cause later commands to fail if they can't
 * reconnect.
 **/
void
camel_pop3_store_expunge (CamelPop3Store *store, CamelException *ex)
{
    camel_pop3_command (store, NULL, "QUIT");
    pop3_disconnect (CAMEL_SERVICE (store), ex);
}


static gboolean
pop3_try_authenticate (CamelService *service, gboolean kpop,
               const char *errmsg, CamelException *ex)
{
    CamelPop3Store *store = (CamelPop3Store *)service;
    int status;
    char *msg;

    /* The KPOP code will have set the password to be the username
     * in connect_to_server. Password and APOP are the only other
     * cases, and they both need a password. So if there's no
     * password stored, query for it.
     */
    if (!service->url->passwd) {
        char *prompt;

        prompt = g_strdup_printf ("%sPlease enter the POP3 password "
                      "for %s@%s", errmsg ? errmsg : "",
                      service->url->user,
                      service->url->host);
        service->url->passwd = camel_session_query_authenticator (
            camel_service_get_session (service),
            CAMEL_AUTHENTICATOR_ASK, prompt, TRUE,
            service, "password", ex);
        g_free (prompt);
        if (!service->url->passwd)
            return FALSE;
    }

    if (!service->url->authmech || kpop) {
        status = camel_pop3_command (store, &msg, "USER %s",
                         service->url->user);
        if (status != CAMEL_POP3_OK) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                          "Unable to connect to POP "
                          "server.\nError sending "
                          "username: %s",
                          msg ? msg : "(Unknown)");
            g_free (msg);
            return FALSE;
        }
        g_free (msg);

        status = camel_pop3_command (store, &msg, "PASS %s",
                         service->url->passwd);
    } else if (!strcmp (service->url->authmech, "+APOP")
           && store->apop_timestamp) {
        char *secret, md5asc[33], *d;
        unsigned char md5sum[16], *s;

        secret = g_strdup_printf ("%s%s", store->apop_timestamp,
                      service->url->passwd);
        md5_get_digest (secret, strlen (secret), md5sum);
        g_free (secret);

        for (s = md5sum, d = md5asc; d < md5asc + 32; s++, d += 2)
            sprintf (d, "%.2x", *s);

        status = camel_pop3_command (store, &msg, "APOP %s %s",
                         service->url->user, md5asc);
    } else {
        camel_exception_set (ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                     "Unable to connect to POP server.\n"
                     "No support for requested authentication "
                     "mechanism.");
        return FALSE;
    }

    if (status != CAMEL_POP3_OK) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                      "Unable to connect to POP server.\n"
                      "Error sending password: %s",
                      msg ? msg : "(Unknown)");
    }

    g_free (msg);
    return camel_exception_is_set (ex);
}

static gboolean
pop3_connect (CamelService *service, CamelException *ex)
{
    char *errbuf = NULL;
    gboolean tryagain, kpop = FALSE;

#ifdef HAVE_KRB4
    kpop = (service->url->authmech &&
        !strcmp (service->url->authmech, "+KPOP"));

    if (kpop && service->url->port == 0)
        service->url->port = KPOP_PORT;
#endif

    d(printf ("POP3: Connecting to %s\n", service->url->host));
    if (!connect_to_server (service, TRUE, ex))
        return FALSE;

    camel_exception_clear (ex);
    do {
        if (camel_exception_is_set (ex)) {
            errbuf = g_strdup_printf (
                "%s\n\n",
                camel_exception_get_description (ex));

            /* Uncache the password before prompting again. */
            camel_session_query_authenticator (
                camel_service_get_session (service),
                CAMEL_AUTHENTICATOR_TELL, NULL, TRUE, service,
                "password", ex);
            g_free (service->url->passwd);
            service->url->passwd = NULL;
        }

        tryagain = pop3_try_authenticate (service, kpop, errbuf, ex);
        g_free (errbuf);
    } while (tryagain);

    if (camel_exception_is_set (ex)) {
        pop3_disconnect (service, NULL);
        return FALSE;
    }

    return service_class->connect (service, ex);
}

static gboolean
pop3_disconnect (CamelService *service, CamelException *ex)
{
    CamelPop3Store *store = CAMEL_POP3_STORE (service);

    if (!service_class->disconnect (service, ex))
        return FALSE;

    d(printf ("POP3: Disconnecting from %s\n", service->url->host));

    if (store->ostream) {
        camel_object_unref (CAMEL_OBJECT (store->ostream));
        store->ostream = NULL;
    }
    if (store->istream) {
        camel_object_unref (CAMEL_OBJECT (store->istream));
        store->istream = NULL;
    }

    if (store->apop_timestamp) {
        g_free (store->apop_timestamp);
        store->apop_timestamp = NULL;
    }

    return TRUE;
}

static CamelFolder *
get_folder (CamelStore *store, const char *folder_name,
        gboolean create, CamelException *ex)
{
    CamelService *service = CAMEL_SERVICE (store);

    if (!camel_service_is_connected (service)) {
        if (!camel_service_connect (service, ex))
            return NULL;
    }
    return camel_pop3_folder_new (store, ex);
}

static char *
get_folder_name (CamelStore *store, const char *folder_name,
         CamelException *ex)
{
    if (!g_strcasecmp (folder_name, "inbox"))
        return g_strdup ("inbox");
    else {
        camel_exception_setv (ex, CAMEL_EXCEPTION_FOLDER_INVALID,
                      "No such folder `%s'.", folder_name);
        return NULL;
    }
}

static char *
get_root_folder_name (CamelStore *store, CamelException *ex)
{
    return g_strdup ("inbox");
}


/**
 * camel_pop3_command: Send a command to a POP3 server.
 * @store: the POP3 store
 * @ret: a pointer to return the full server response in
 * @fmt: a printf-style format string, followed by arguments
 *
 * This command sends the command specified by @fmt and the following
 * arguments to the connected POP3 store specified by @store. It then
 * reads the server's response and parses out the status code. If
 * the caller passed a non-NULL pointer for @ret, camel_pop3_command
 * will set it to point to an buffer containing the rest of the
 * response from the POP3 server. (If @ret was passed but there was
 * no extended response, @ret will be set to NULL.) The caller must
 * free this buffer when it is done with it.
 *
 * Return value: one of CAMEL_POP3_OK (command executed successfully),
 * CAMEL_POP3_ERR (command encounted an error), or CAMEL_POP3_FAIL
 * (a protocol-level error occurred, and Camel is uncertain of the
 * result of the command.)
 **/
int
camel_pop3_command (CamelPop3Store *store, char **ret, char *fmt, ...)
{
    char *cmdbuf;
    va_list ap;

    if (!store->ostream) {
        CamelException ex;

        camel_exception_init (&ex);
        if (!camel_service_connect (CAMEL_SERVICE (store), &ex)) {
            if (ret)
                *ret = g_strdup (camel_exception_get_description (&ex));
            camel_exception_clear (&ex);
            return CAMEL_POP3_FAIL;
        }
    }

    va_start (ap, fmt);
    cmdbuf = g_strdup_vprintf (fmt, ap);
    va_end (ap);

#if d(!)0
    if (!strncmp (cmdbuf, "PASS", 4))
        printf ("POP3: >>> PASS xxx\n");
    else
        printf ("POP3: >>> %s\n", cmdbuf);
#endif

    /* Send the command */
    if (camel_stream_printf (store->ostream, "%s\r\n", cmdbuf) == -1) {
        g_free (cmdbuf);
        if (*ret)
            *ret = g_strdup (g_strerror (errno));
        d(printf ("POP3: !!! %s\n", g_strerror (errno)));
        return CAMEL_POP3_FAIL;
    }
    g_free (cmdbuf);

    return pop3_get_response (store, ret);
}

static int
pop3_get_response (CamelPop3Store *store, char **ret)
{
    char *respbuf;
    int status;

    respbuf = camel_stream_buffer_read_line (
        CAMEL_STREAM_BUFFER (store->istream));
    if (respbuf == NULL) {
        if (ret)
            *ret = g_strdup (g_strerror (errno));
        d(printf ("POP3: !!! %s\n", g_strerror (errno)));
        return CAMEL_POP3_FAIL;
    }
    d(printf ("POP3: <<< %s\n", respbuf));

    if (!strncmp (respbuf, "+OK", 3))
        status = CAMEL_POP3_OK;
    else if (!strncmp (respbuf, "-ERR", 4))
        status = CAMEL_POP3_ERR;
    else
        status = CAMEL_POP3_FAIL;

    if (ret) {
        if (status != CAMEL_POP3_FAIL) {
            *ret = strchr (respbuf, ' ');
            if (*ret)
                *ret = g_strdup (*ret + 1);
        } else
            *ret = NULL;
    }
    g_free (respbuf);

    return status;
}

/**
 * camel_pop3_command_get_additional_data: get "additional data" from
 * a POP3 command.
 * @store: the POP3 store
 *
 * This command gets the additional data returned by "multi-line" POP
 * commands, such as LIST, RETR, TOP, and UIDL. This command _must_
 * be called after a successful (CAMEL_POP3_OK) call to
 * camel_pop3_command for a command that has a multi-line response.
 * The returned data is un-byte-stuffed, and has lines termined by
 * newlines rather than CR/LF pairs.
 *
 * Return value: the data, which the caller must free.
 **/
char *
camel_pop3_command_get_additional_data (CamelPop3Store *store, CamelException *ex)
{
    CamelStreamBuffer *stream = CAMEL_STREAM_BUFFER (store->istream);
    GPtrArray *data;
    char *buf, *p;
    int i, len = 0, status = CAMEL_POP3_OK;

    data = g_ptr_array_new ();
    while (1) {
        buf = camel_stream_buffer_read_line (stream);
        if (!buf) {
            status = CAMEL_POP3_FAIL;
            break;
        }

        if (!strcmp (buf, "."))
            break;

        g_ptr_array_add (data, buf);
        len += strlen (buf) + 1;
    }
    g_free (buf);

    if (status == CAMEL_POP3_OK) {
        buf = g_malloc0 (len + 1);

        for (i = 0, p = buf; i < data->len; i++) {
            char *ptr, *datap;

            datap = (char *) data->pdata[i];
            ptr = (*datap == '.') ? datap + 1 : datap;
            len = strlen (ptr);
#if d(!)0
            if (i == data->len - 1)
                printf ("POP3: <<<<<< %s\n", ptr);
            else if (i == 0)
                printf ("POP3: <<<<<< %s...\n", ptr);
#endif
            memcpy (p, ptr, len);
            p += len;
            *p++ = '\n';
        }
        *p = '\0';
    } else
        buf = NULL;

    for (i = 0; i < data->len; i++)
        g_free (data->pdata[i]);
    g_ptr_array_free (data, TRUE);

    return buf;
}