Bug #695 remove FORCE_ALIGN

macOS 11.6 mistakenly detected as a system that requires FORCE_ALIGN, which caused many tcprewrite tests to fail. It appears that this code has become broken over the years, and this bug was never detected. That's because there probably aren't any ULTRA Sparc systems out there anymore. Rather than attempting to fix, removed FORCE_ALIGN. Too bad if you still run an ULTRA Sparc.
appneta · Jan 28, 2022 · af0d523 · af0d523
1 parent 2f1d91f
commit af0d523
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Showing 9 changed files with 4 additions and 188 deletions.
diff --git a/configure.ac b/configure.ac
@@ -1699,71 +1699,6 @@ fi
 
 fi # checking pcapnav version
 
-
-dnl (shamelessly ripped off from libpcap)
-dnl Checks to see if unaligned memory accesses fail
-dnl
-dnl     FORCE_ALIGN (DEFINED)
-dnl
-AC_MSG_CHECKING(for requires strict byte alignment)
-AC_CACHE_VAL(unaligned_cv_fail,
-        [case "$host_cpu" in
-
-        # XXX: should also check that they don't do weird things (like on arm)
-        alpha*|arm*|hp*|mips*|sparc*|ia64)
-                unaligned_cv_fail=yes
-                ;;
-
-        *)
-        cat >conftest.c <<EOF
-        #include <sys/types.h>
-        #include <sys/wait.h>
-        #include <stdio.h>
-        unsigned char a[[5]] = { 1, 2, 3, 4, 5 };
-        main() {
-            unsigned int i;
-            pid_t pid;
-            int status;
-            /* avoid "core dumped" message */
-            pid = fork();
-            if (pid <  0)
-                exit(2);
-            if (pid > 0) {
-                /* parent */
-                pid = waitpid(pid, &status, 0);
-                if (pid < 0)
-                        exit(3);
-                exit(!WIFEXITED(status));
-            }
-            /* child */
-            i = *(unsigned int *)&a[[1]];
-            printf("%d\n", i);
-            exit(0);
-        }
-EOF
-        ${CC-cc} -o conftest $CFLAGS $CPPFLAGS $LDFLAGS \
-            conftest.c $LIBS >/dev/null 2>&1
-        if test ! -x conftest ; then
-            dnl failed to compile for some reason
-            unaligned_cv_fail=yes
-        else
-            ./conftest >conftest.out
-            if test ! -s conftest.out ; then
-                unaligned_cv_fail=yes
-            else
-                unaligned_cv_fail=no
-            fi
-        fi
-        rm -f conftest* core core.conftest
-        ;;
-
-        esac
-    ])
-AC_MSG_RESULT($unaligned_cv_fail)
-if test $unaligned_cv_fail = yes ; then
-    AC_DEFINE([FORCE_ALIGN], [1], [Are we strictly aligned?])
-fi
-
 dnl ##################################################
 dnl # Check for tcpdump.
 dnl ##################################################

diff --git a/docs/CHANGELOG b/docs/CHANGELOG
@@ -1,4 +1,5 @@
 06/19/2021 Version 4.4.0-beta2
+    - remove obsolete FORCE_ALIGN support to fix macOS 11 compile (#695)
     - add a security policy document (#689)
     - ability to specify directory of pcap files (#682)
     - incorrect PPS rate for long-running sessions (#679)

diff --git a/src/common/get.c b/src/common/get.c
@@ -460,29 +460,11 @@ get_ipv4(const u_char *pktdata, int datalen, int datalink, u_char **newbuff)
     l2len -= l2offset;
     pkt_len -= l2offset;
 
-#ifdef FORCE_ALIGN
-    /*
-     * copy layer 3 and up to our temp packet buffer
-     * for now on, we have to edit the packetbuff because
-     * just before we send the packet, we copy the packetbuff 
-     * back onto the pkt.data + l2len buffer
-     * we do all this work to prevent byte alignment issues
-     */
-    if (l2len % sizeof(long)) {
-        memcpy(*newbuff, (packet + l2len), (pkt_len - l2len));
-        ip_hdr = *newbuff;
-    } else {
-
-        /* we don't have to do a memcpy if l2len lands on a boundary */
-        ip_hdr = (packet + l2len);
-    }
-#else
     /*
      * on non-strict byte align systems, don't need to memcpy(), 
      * just point to l2len bytes into the existing buffer
      */
     ip_hdr = (packet + l2len);
-#endif
 
     return ip_hdr;
 }
@@ -535,29 +517,11 @@ get_ipv6(const u_char *pktdata, int datalen, int datalink, u_char **newbuff)
     l2len -= l2offset;
     pkt_len -= l2offset;
 
-#ifdef FORCE_ALIGN
-    /*
-     * copy layer 3 and up to our temp packet buffer
-     * for now on, we have to edit the packetbuff because
-     * just before we send the packet, we copy the packetbuff
-     * back onto the pkt.data + l2len buffer
-     * we do all this work to prevent byte alignment issues
-     */
-    if (l2len % sizeof(long)) {
-        memcpy(*newbuff, (packet + l2len), (pkt_len - l2len));
-        ip6_hdr = *newbuff;
-    } else {
-
-        /* we don't have to do a memcpy if l2len lands on a boundary */
-        ip6_hdr = (packet + l2len);
-    }
-#else
     /*
      * on non-strict byte align systems, don't need to memcpy(),
      * just point to l2len bytes into the existing buffer
      */
     ip6_hdr = (packet + l2len);
-#endif
 
     return ip6_hdr;
 }

diff --git a/src/tcpedit/edit_packet.c b/src/tcpedit/edit_packet.c
@@ -953,9 +953,6 @@ randomize_iparp(tcpedit_t *tcpedit, struct pcap_pkthdr *pkthdr,
 {
     arp_hdr_t *arp_hdr ;
     int l2len;
-#ifdef FORCE_ALIGN
-    uint32_t iptemp;
-#endif
 
     assert(tcpedit);
     assert(pkthdr);
@@ -982,30 +979,12 @@ randomize_iparp(tcpedit_t *tcpedit, struct pcap_pkthdr *pkthdr,
         u_char *add_hdr = ((u_char *)arp_hdr) + sizeof(arp_hdr_t) +
                 arp_hdr->ar_hln;
 
-#ifdef FORCE_ALIGN
-        /* copy IP to a temporary buffer for processing */
-        memcpy(&iptemp, add_hdr, sizeof(uint32_t));
-        ip = &iptemp;
-#else
         ip = (uint32_t *)add_hdr;
-#endif
         *ip = randomize_ipv4_addr(tcpedit, *ip);
-#ifdef FORCE_ALIGN
-        memcpy(add_hdr, &iptemp, sizeof(uint32_t));
-#endif
 
         add_hdr += arp_hdr->ar_pln + arp_hdr->ar_hln;
-#ifdef FORCE_ALIGN
-        /* copy IP2 to a temporary buffer for processing */
-        memcpy(&iptemp, add_hdr, sizeof(uint32_t));
-        ip = &iptemp;
-#else
         ip = (uint32_t *)add_hdr;
-#endif
         *ip = randomize_ipv4_addr(tcpedit, *ip);
-#ifdef FORCE_ALIGN
-        memcpy(add_hdr, &iptemp, sizeof(uint32_t));
-#endif
     }
 
     return 1; /* yes we changed the packet */
@@ -1027,9 +1006,6 @@ rewrite_iparp(tcpedit_t *tcpedit, arp_hdr_t *arp_hdr, int cache_mode)
     uint32_t newip = 0;
     tcpr_cidrmap_t *cidrmap1 = NULL, *cidrmap2 = NULL;
     int didsrc = 0, diddst = 0, loop = 1;
-#ifdef FORCE_ALIGN
-    uint32_t iptemp;
-#endif
 
     assert(tcpedit);
     assert(arp_hdr);
@@ -1061,14 +1037,7 @@ rewrite_iparp(tcpedit_t *tcpedit, arp_hdr_t *arp_hdr, int cache_mode)
         add_hdr += sizeof(arp_hdr_t) + arp_hdr->ar_hln;
         ip1 = (uint32_t *)add_hdr;
         add_hdr += arp_hdr->ar_pln + arp_hdr->ar_hln;
-#ifdef FORCE_ALIGN
-        /* copy IP2 to a temporary buffer for processing */
-        memcpy(&iptemp, add_hdr, sizeof(uint32_t));
-        ip2 = &iptemp;
-#else
         ip2 = (uint32_t *)add_hdr;
-#endif
-
 
         /* loop through the cidrmap to rewrite */
         do {
@@ -1099,31 +1068,24 @@ rewrite_iparp(tcpedit_t *tcpedit, arp_hdr_t *arp_hdr, int cache_mode)
                 }
             }
 
-#ifdef FORCE_ALIGN
-            /* copy temporary IP to IP2 location in buffer */
-            memcpy(add_hdr, &iptemp, sizeof(uint32_t));
-#endif
-
             /*
              * loop while we haven't modified both src/dst AND
              * at least one of the cidr maps have a next pointer
              */
             if ((! (diddst && didsrc)) &&
                 (! ((cidrmap1->next == NULL) && (cidrmap2->next == NULL)))) {
-                
+
                 /* increment our ptr's if possible */
                 if (cidrmap1->next != NULL)
                     cidrmap1 = cidrmap1->next;
-                
+
                 if (cidrmap2->next != NULL)
                     cidrmap2 = cidrmap2->next;
-
             } else {
                 loop = 0;
             }
 
         } while (loop);
-
     } else {
         warn("ARP packet isn't for IPv4!  Can't rewrite IP's");
     }

diff --git a/src/tcpedit/plugins/dlt_plugins.c b/src/tcpedit/plugins/dlt_plugins.c
@@ -130,9 +130,6 @@ tcpedit_dlt_init(tcpedit_t *tcpedit, const int srcdlt)
     ctx = (tcpeditdlt_t *)safe_malloc(sizeof(tcpeditdlt_t));
 
     /* do we need a side buffer for L3 data? */
-#ifdef FORCE_ALIGN
-    ctx->l3buff = (u_char *)safe_malloc(MAXPACKET);
-#endif
 
     /* copy our tcpedit context */
     ctx->tcpedit = tcpedit;
@@ -469,10 +466,6 @@ tcpedit_dlt_cleanup(tcpeditdlt_t *ctx)
         plugin = plugin_next;
     }
 
-#ifdef FORCE_ALIGN
-    safe_free(ctx->l3buff);
-#endif
-
     if (ctx->decoded_extra != NULL) {
         safe_free(ctx->decoded_extra);
         ctx->decoded_extra = NULL;

diff --git a/src/tcpedit/plugins/dlt_utils.c b/src/tcpedit/plugins/dlt_utils.c
@@ -203,28 +203,11 @@ tcpedit_dlt_l3data_copy(tcpeditdlt_t *ctx, u_char *packet, int pktlen, int l2len
 
     if (pktlen <= l2len)
         return NULL;
-
-#ifdef FORCE_ALIGN
-    /* 
-     * copy layer 3 and up to our temp packet buffer
-     * for now on, we have to edit the packetbuff because
-     * just before we send the packet, we copy the packetbuff 
-     * back onto the pkt.data + l2len buffer
-     * we do all this work to prevent byte alignment issues
-     */
-    if (l2len % 4 == 0) {
-        ptr = (&(packet)[l2len]);
-    } else {
-        ptr = ctx->l3buff;
-        memcpy(ptr, (&(packet)[l2len]), pktlen - l2len);
-    }
-#else
+
     /*
-     * on non-strict byte align systems, don't need to memcpy(), 
      * just point to 14 bytes into the existing buffer
      */
     ptr = (&(packet)[l2len]);
-#endif
     return ptr;
 }
 
@@ -239,14 +222,6 @@ tcpedit_dlt_l3data_merge(tcpeditdlt_t *ctx, u_char *packet, int pktlen, const u_
     assert(pktlen >= 0);
     assert(l3data);
     assert(l2len >= 0);
-#ifdef FORCE_ALIGN
-    /* 
-     * put back the layer 3 and above back in the pkt.data buffer 
-     * we can't edit the packet at layer 3 or above beyond this point
-     */
-     if (l2len % 4 != 0)
-         memcpy((&(packet)[l2len]), l3data, pktlen - l2len);
-#endif
     return packet;
 }
 

diff --git a/src/tcpedit/plugins_types.h b/src/tcpedit/plugins_types.h
@@ -103,9 +103,7 @@ struct tcpeditdlt_plugin_s {
  */
 struct tcpeditdlt_s {
     tcpedit_t *tcpedit;                 /* pointer to our tcpedit context */
-#ifdef FORCE_ALIGN
     u_char *l3buff;                     /* pointer for L3 buffer on strictly aligned systems */
-#endif
     tcpeditdlt_plugin_t *plugins;       /* registered plugins */
     tcpeditdlt_plugin_t *decoder;       /* Encoder plugin */
     tcpeditdlt_plugin_t *encoder;       /* Decoder plugin */      

diff --git a/src/tcpedit/tcpedit.c b/src/tcpedit/tcpedit.c
@@ -401,10 +401,6 @@ tcpedit_init(tcpedit_t **tcpedit_ex, int dlt)
     dbgx(1, "Input file (1) datalink type is %s",
             pcap_datalink_val_to_name(dlt));
 
-#ifdef FORCE_ALIGN
-    tcpedit->runtime.l3buff = (u_char *)safe_malloc(MAXPACKET);
-#endif
-
     return TCPEDIT_OK;
 }
 
@@ -619,11 +615,6 @@ tcpedit_close(tcpedit_t **tcpedit_ex)
         tcpedit->portmap = NULL;
     }
 
-#ifdef FORCE_ALIGN
-    safe_free(tcpedit->runtime.l3buff);
-    tcpedit->runtime.l3buff = NULL;
-#endif
-
     safe_free(*tcpedit_ex);
     *tcpedit_ex = NULL;
 

diff --git a/src/tcpedit/tcpedit_types.h b/src/tcpedit/tcpedit_types.h
@@ -69,9 +69,6 @@ typedef struct {
     int dlt2;
     char errstr[TCPEDIT_ERRSTR_LEN];
     char warnstr[TCPEDIT_ERRSTR_LEN];
-#ifdef FORCE_ALIGN    
-    u_char *l3buff;
-#endif
 } tcpedit_runtime_t;
 
 /*