NAME
SYNOPSIS
#include
DESCRIPTION
imclient_connect()
imclient_servername()
imclient_addcallback()
imclient_processoneevent()
imclient_authenticate()
EXAMPLES
BUGS
SEE ALSO
select(2)
KEYWORDS
COPYRIGHT

NAME

imclient library - authenticating callback interface to IMAP/IMSP servers

SYNOPSIS

#include

int imclient_connect(struct imclient **imclient, const char *host, const char *port);

void imclient_close (struct imclient *imclient);

void imclient_setflags(struct imclient *imclient, intflags);

void imclient_clearflags (struct imclient *imclient, intflags);

char* imclient_servername (struct imclient *imclient);

void imclient_addcallback (struct imclient * imclient ,...);

void imclient_send (struct imclient *imclient, void (*finishproc)(), void *finishrock, const char *fmt, ...);

void imclient_getselectinfo (struct imclient *imclient, int *fd, int * wanttowrite);

void imclient_processoneevent (struct imclient *imclient);

int imclient_authenticate (struct imclient *imclient, struct sasl_client **availmech, const char *service, const
char *user, int protallowed);

DESCRIPTION

The imclient library functions are distributed with Cyrus IMAP and IMSP. These functions are used for building
IMAP/IMSP client software. These functions handle Kerberos authentication and can set callbacks based on the
keyword in untagged replies or based on the command tag at the end of command replies.

Users must link with the -lcyrus switch, and must supply a function called fatal to be called in case of any error
within libcyrus.a.

All of the imclient functions begin with the prefix imclient and takes an argument of type struct imclient * as the
first argument which is initialized by imclient_connect and freed by imclient_close.

See below for a description of each function.

imclient_connect()

Connects the client server to the host. If successful, it returns 0 and sets the imclient argument to a pointer to
an imclient struct. The imclient struct represents the current connection, flags, and callbacks. On failure,
the current errno is returned if a system call failed, -1 is returned if the host name was not found, and -2 is
returned if the service name was not found.

imclient_close()

Closes and frees the imclient connection.

imclient_setflags()
Sets the flags specified by the flags argument on the imclient connection. Currently the only flag allowed is
IMCLIENT_CONN_NONSYNCLITERAL (this flag indicates that the server supports non-synchronizing
literals described by the LITERAL+ extension).

imclient_clearflags()
Clears the flags specified by the flags argument on the imclient connection.

imclient_servername()

Returns a char * pointer to the name of the server connected to by imclient.

imclient_addcallback()

Adds an untagged data callback to the imclient connection. The function imclient_addcallback takes call-
backs of the type imclient_proc_t which is defined to be:
typedef void imclient_proc_t (struct imclient *imclient, void *rock, struct imclient_reply
*reply);

and struct imclient_reply * is defined to be:

struct imclient_reply {
char *keyword;
long msgno;
char *text;
};

After the first argument imclient, there can be zero or more instances of the set of keyword, flags, proc, and

rock, each adding or changing a single callback. Each instance adds or changes the callback for keyword.
The argument, flags, specifies information about the parsing of the untagged data. proc and rock specify the
callback function and rock to invoke when the untagged data is received. proc may be a null pointer, in
which case no function is invoked. The callback function may not call the functions imclient_close(),
imclient_send(), imclient_eof(), imclient_processoneevent(), or imclient_authenticate() on the connec-
tion. The callback function may over write the text of untagged data.

imclient_send()

Sends a new command to the imclient connection. finishproc and finnishrock are the function and rock
called when the command completes. functionproc may be a null pointer, in which case no callback is
made. The call back function may not call the functions imclient_close(), imclient_send(), imclient_eof(),
imclient_processoneevent(), or imclient_authenticate() on the connection. The argument, fmt , is a print
like specification of the command. It must not include the tag as the tag is automatically added by
imclient_send(). The defined %-sequences are:

%% for %

%a for an IMAP atom

%s for an astring (which will be quoted or literalized as needed)

%d for a decimal

%u for an unsigned decimal

%v for #astring (argument is a null-terminated array of char * which are written as
space separated astrings)

imclient_getselectinfo()
Gets the information for calling select(2). fd is filled in with the file descriptor to select(2) for read. want-
towrite is filled in with a nonzero value if select should be used for write as well.

imclient_processoneevent()

Processes one input or output event on the imclient connection.

imclient_authenticate()

Authenticates the imclient connection using one of the mechanisms in availmech. The argument, user, if not
NULL, specifies the user to authenticate as. If the user is NULL, the current user is used. The argument
protallowed is a bitmask of permissible protection mechanisms.

On success, 0 is returned. On failure (i.e., "BAD" keyboard, or no authentication mechanisms worked), 1 is
returned. On extreme failure (premature "OK"), 2 is returned.

EXAMPLES

The following code is a possible skeletion of imclient that relies on Kerberos to do authentication. This code pre-
forms an IMAP CAPABILITY request and prints out the result.

struct sasl_client;
#include <cyrus/xmalloc.h> /* example uses xstrdup */
#include <cyrus/sasl.h>
#include <cyrus/imclient.h>
#include <stdio.h>

extern struct sasl_client krb_sasl_client;

struct sasl_client *login_sasl_client[] = {

&krb_sasl_client,
NULL

};
struct imclient *imclient;
char server[] = "cyrus.andrew.cmu.edu" ;
char port[] = "imap";

void fatal(char* message, int rc) {

fprintf(stderr, "fatal error: %s\n", message);
exit(rc);
}

static void callback_capability(struct imclient *imclient,
void *rock,

struct imclient_reply *reply) {

}

if (reply->text != NULL) {
*((char**)rock) = xstrdup( reply->text );
}

static void end_command (struct imclient *connection, void*
rock, struct imclient_reply *inmsg) {
(*(int*)rock)--;
}

main() {

		char* capability_string; int nc; if (imclient_connect(&imclient, server, port)) { fprintf(stderr, "error: Couldn't connect to %s %s\n", server, port); exit(1); } if (imclient_authenticate(imclient, login_sasl_client, "imap" /* service /, NULL / user /, SASL_PROT_ANY)) { exit(1); } imclient_addcallback(imclient, "CAPABILITY", CALLBACK_NOLITERAL, callback_capability, &capability_string, NULL); nc = 1; imclient_send(imclient, end_command, (void) &nc, "CAPABILITY"); while(nc > 0) { imclient_processoneevent(imclient); } if (strstr("LITERAL+", capability_string)) { imclient_setflags(imclient, IMCLIENT_CONN_NONSYNCLITERAL); } imclient_send(imclient, NULL, NULL, "LOGOUT"); imclient_close(imclient); printf("capability text is: %s\n", capability_string); free(capability_string);
}

BUGS

No known bugs.

select(2)

KEYWORDS

IMAP, ACAP, IMSP, Kerberos, Authentication

COPYRIGHT

This software is made available for academic and research purposes only. No commercial license is hereby
granted. Copying and other reproduction is authorized only for research, education, and other non-commercial
purposes. No warranties, either expressed or implied, are made regarding the operation, use, or results of the
software. Such a release does not permit use of the code for commercial purposes or benefits by anyone without specific, additional permission by the owner of the code.