sendmail, 4th Edition

Milter smfi_setpriv()

Set aside private data for later use All sendmail versions

Often, a Milter will need private data to keep track of things such as individual headers viewed, or will need to buffer data, such as the parts of a message’s body. The Milter library provides a means to set aside and use private data. You declare the data using this smfi_setpriv() routine, then later fetch it using the smfi_getpriv() routine (Milter smfi_getpriv() on page 1189). The smfi_setpriv() routine is used like this:

ret = smfi_setpriv(ctx, datap);

Here, ctx is the common context pointer that was passed to your xxfi_eom() function. The datap is a pointer that contains the address of your data. The smfi_setpriv() routine expects a datap that is of type void *, so you may need to cast your call, depending on how picky your compiler is:

ret = smfi_setpriv(ctx, (void *)datap);

The data to which datap points must not be automatic or local because it must survive calls to multiple xxfi_ functions. Instead, you should allocate the space and free it when done. Consider, for example, the following:

typedef struct {
    char        **rheads;
    int           nheads;
} MY_DATUM;

MY_DATUM *mdp = calloc(1, sizeof(MY_DATUM));

ret = smfi_setpriv(ctx, mdp);

Each context (ctx) may have only one private data pointer. If you call smfi_setpriv() twice with the same ctx, the first pointer will be discarded and replaced with the second, possibly resulting in a memory leak.

The return value (ret) will be MI_FAILURE only if the context pointer ...