From: Florian Forster Date: Tue, 9 Aug 2016 14:35:15 +0000 (+0200) Subject: src/liboping.c: Simplify packet creation and parsing. X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=6949f72a7f2ca6237a3e18bb12d5efbb61c2d1df;p=liboping.git src/liboping.c: Simplify packet creation and parsing. --- diff --git a/src/liboping.c b/src/liboping.c index f3c850e..f8c5bfb 100644 --- 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);