src/modemman.c


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#include "modemman.h"
#include "modem.h"

#define MAX_CHANNELS 10
#define TTY_START 11

struct llist {
    struct modem *modem;
    struct llist *next;
};

static struct llist *llist = NULL;
static int n_llist = 0;

int modem_manager_init(int channels) {
    int i;

    assert(channels <= MAX_CHANNELS && channels > 0); 
    assert(n_llist == 0);
    
    for (i = TTY_START; i < TTY_START+MAX_CHANNLES && n_llist < channels; i++) {
        char d[PATH_MAX];
        struct modem *m;

        snprintf(d, sizeof(d), "/dev/ttyI%i", i);

        if (m = modem_open(d)) {
            struct llist *l = malloc(sizeof(struct llist));
            assert(l);

            l->modem = m;
            l->next = llist;
            llist = l;
            n_llist++;
        }
    }

    if (n_llist < channels) {
        daemon_log(LOG_ERR, "Failed to allocate the requested channels. Got %i of %i.", n_llist, channels);
        modem_manager_done();
        return -1;
    }

    return 0;
}

void modem_manager_done(void) {

    while (llist) {
        struct llist *l;

        modem_close(l->modem);
        l = llist;
        llist = l->next;
        free(l);
        n_llist = 0;
    }

    assert(!n_llist && !llist);
}