llist.c

#include <stdio.h>

/* --- cut here ------------------------------------------------------------- */
#include <assert.h>
struct llist {
        struct llist *next;
};
#define LLIST_HEAD_INIT { NULL }

static inline void llist_add(struct llist *head, struct llist *node)
{
        assert(head && node);
        struct llist *p = head;
        while (p->next) p = p->next;
        p->next = node; node->next = NULL;
}
#define offset_of(type, member) ((unsigned long) &((type *)0)->member)
#define container_of(ptr, type, member) \
        ((type *) ((char *)ptr - offset_of(type, member)))
/* ptr  => pointer to your struct
 * head => start of list
 * type => struct type where struct llist is embedded
 * member => the name of the struct llist member embedded in type */
#define llist_foreach(ptr, head, type, member)                        \
        for ((ptr) = container_of((head)->next, type, member);        \
             ptr;                                                     \
             ptr   = ((ptr)->member.next ?                            \
                      container_of((ptr)->member.next, type, member)  \
                      : NULL))
/* --- cut here------------------------------------------------------------ */


struct foo {
        char *name;
        struct llist l;
};

int main(void)
{
        struct llist head = LLIST_HEAD_INIT;
        struct foo bar, tar, zar;
        bar.name = "bar";
        tar.name = "tar";
        zar.name = "zar";
        llist_add(&head, &bar.l);
        llist_add(&head, &tar.l);
        llist_add(&head, &zar.l);
        struct foo *p;
        llist_foreach(p, &head, struct foo, l)
                puts(p->name);

        return 0;
}