src/liboping.c: Simplify packet creation and parsing.

diff --git a/src/liboping.c b/src/liboping.c
index f3c850e..f8c5bfb 100644 (file)
--- a/src/liboping.c
+++ b/src/liboping.c
@@ -302,19 +302,16 @@ static pinghost_t *ping_receive_ipv4 (pingobj_t *obj, char *buffer,
                return (NULL);
 
        icmp_hdr = (struct icmp *) buffer;
-       buffer     += ICMP_MINLEN;
-       buffer_len -= ICMP_MINLEN;
-
        if (icmp_hdr->icmp_type != ICMP_ECHOREPLY)
        {
-               dprintf ("Unexpected ICMP type: %i\n", icmp_hdr->icmp_type);
+               dprintf ("Unexpected ICMP type: %"PRIu8"\n", icmp_hdr->icmp_type);
                return (NULL);
        }
 
        recv_checksum = icmp_hdr->icmp_cksum;
+       /* This writes to buffer. */
        icmp_hdr->icmp_cksum = 0;
-       calc_checksum = ping_icmp4_checksum ((char *) icmp_hdr,
-                       ICMP_MINLEN + buffer_len);
+       calc_checksum = ping_icmp4_checksum (buffer, buffer_len);
 
        if (recv_checksum != calc_checksum)
        {
@@ -815,29 +812,28 @@ static int ping_send_one_ipv4 (pingobj_t *obj, pinghost_t *ph)
        struct icmp *icmp4;
        int status;
 
-       char buf[4096];
-       int  buflen;
+       char   buf[4096] = {0};
+       size_t buflen;
 
        char *data;
-       int   datalen;
+       size_t datalen;
 
        dprintf ("ph->hostname = %s\n", ph->hostname);
 
-       memset (buf, '\0', sizeof (buf));
        icmp4 = (struct icmp *) buf;
-       data  = buf + ICMP_MINLEN;
-
-       icmp4->icmp_type  = ICMP_ECHO;
-       icmp4->icmp_code  = 0;
-       icmp4->icmp_cksum = 0;
-       icmp4->icmp_id    = htons (ph->ident);
-       icmp4->icmp_seq   = htons (ph->sequence);
+       *icmp4 = (struct icmp) {
+               .icmp_type = ICMP_ECHO,
+               .icmp_id   = htons (ph->ident),
+               .icmp_seq  = htons (ph->sequence),
+       };
 
-       buflen = sizeof(buf) - ICMP_MINLEN;
-       strncpy (data, ph->data, buflen);
-       datalen = strlen (data);
+       datalen = strlen (ph->data);
+       buflen = ICMP_MINLEN + datalen;
+       if (sizeof (buf) < buflen)
+               return (EINVAL);
 
-       buflen = datalen + ICMP_MINLEN;
+       data  = buf + ICMP_MINLEN;
+       memcpy (data, ph->data, datalen);
 
        icmp4->icmp_cksum = ping_icmp4_checksum (buf, buflen);
 
@@ -860,7 +856,7 @@ static int ping_send_one_ipv6 (pingobj_t *obj, pinghost_t *ph)
        struct icmp6_hdr *icmp6;
        int status;
 
-       char buf[4096];
+       char buf[4096] = {0};
        int  buflen;
 
        char *data;
@@ -868,23 +864,22 @@ static int ping_send_one_ipv6 (pingobj_t *obj, pinghost_t *ph)
 
        dprintf ("ph->hostname = %s\n", ph->hostname);
 
-       memset (buf, '\0', sizeof (buf));
        icmp6 = (struct icmp6_hdr *) buf;
-       data  = (char *) (icmp6 + 1);
+       *icmp6 = (struct icmp6_hdr) {
+               .icmp6_type  = ICMP6_ECHO_REQUEST,
+               .icmp6_id    = htons (ph->ident),
+               .icmp6_seq   = htons (ph->sequence),
+       };
 
-       icmp6->icmp6_type  = ICMP6_ECHO_REQUEST;
-       icmp6->icmp6_code  = 0;
-       /* The checksum will be calculated by the TCP/IP stack.  */
-       /* FIXME */
-       icmp6->icmp6_cksum = 0;
-       icmp6->icmp6_id    = htons (ph->ident);
-       icmp6->icmp6_seq   = htons (ph->sequence);
+       datalen = strlen (ph->data);
+       buflen = sizeof (*icmp6) + datalen;
+       if (sizeof (buf) < buflen)
+               return (EINVAL);
 
-       buflen = 4096 - ICMP_MINLEN;
-       strncpy (data, ph->data, buflen);
-       datalen = strlen (data);
+       data  = buf + ICMP_MINLEN;
+       memcpy (data, ph->data, datalen);
 
-       buflen = datalen + ICMP_MINLEN;
+       /* The checksum will be calculated by the TCP/IP stack. */
 
        dprintf ("Sending ICMPv6 package with ID 0x%04x\n", ph->ident);