Try to fix (most) unaligned memory access (See #3213)

.github/workflows/build.yml

@@ -107,6 +107,7 @@ jobs:
             pcre: "--with-pcre2"
             maxminddb: "--with-maxminddb"
             msan: "--with-sanitizer"
+            cflags: "-fno-sanitize-recover=all"
           - compiler: "cc"
             os: macOS-latest
             pcre: "--with-pcre2"

configure.ac

@@ -79,9 +79,9 @@ AS_IF([test "${with_sanitizer+set}" = set],[
   NDPI_LDFLAGS="${NDPI_LDFLAGS} -fsanitize=address -fsanitize=undefined -fsanitize=leak"
   #Sanitizers should work on any compilers that we support (or that we test on CI, at least)
   #Exception: "-fsanitize=alignment" is not supported in gcc 4.9
-  AX_CHECK_COMPILE_FLAG([-fno-sanitize=alignment], [
-    NDPI_CFLAGS="${NDPI_CFLAGS} -fno-sanitize=alignment"
-    NDPI_LDFLAGS="${NDPI_LDFLAGS} -fno-sanitize=alignment"
+  AX_CHECK_COMPILE_FLAG([-fsanitize=alignment], [
+    NDPI_CFLAGS="${NDPI_CFLAGS} -fsanitize=alignment"
+    NDPI_LDFLAGS="${NDPI_LDFLAGS} -fsanitize=alignment"
   ])
 ])
 
@@ -302,7 +302,7 @@ echo "Setting API version to ${NDPI_API_VERSION}"
 AC_DEFINE_UNQUOTED(NDPI_GIT_RELEASE, "${GIT_RELEASE}", [GIT Release])
 AC_DEFINE_UNQUOTED(NDPI_GIT_DATE, "${GIT_DATE}", [Last GIT change])
 
-NDPI_CFLAGS="-W -Wall -Wextra -Wno-address-of-packed-member ${NDPI_CFLAGS}"
+NDPI_CFLAGS="-W -Wall -Wextra ${NDPI_CFLAGS}"
 
 dnl> MacOS brew.sh
 HOMEBREW_DIR=/opt/homebrew

example/reader_util.h

@@ -285,7 +285,10 @@ typedef struct ndpi_flow_info {
     } bfcp;
   };
 
-  ndpi_serializer ndpi_flow_serializer;
+  struct {
+    uint8_t _alignment[4];
+    ndpi_serializer ndpi_flow_serializer;
+  };
 
   char host_server_name[80]; /* Hostname/SNI */
   char *server_hostname;

src/include/ndpi_typedefs.h

@@ -684,8 +684,8 @@ struct ndpi_binary_bitmap_entry {
 
 typedef union
 {
-  u_int32_t ipv4;
   struct ndpi_in6_addr ipv6;
+  u_int32_t ipv4;
 } ndpi_ip_addr_t;
 
 
@@ -2257,7 +2257,7 @@ typedef struct {
 typedef ndpi_ranking_epoch_entry ndpi_ranking_change;
 
 typedef struct {
-  u_int32_t epoch;
+  u_int64_t epoch;
   ndpi_ranking_epoch_entry *entries;
 } ndpi_ranking_epoch;
 

src/lib/ndpi_analyze.c

@@ -2308,7 +2308,7 @@ void ndpi_print_ranking(ndpi_ranking *rank) {
     ndpi_ranking_epoch_entry *this_entries = (ndpi_ranking_epoch_entry*)&rank->epochs[i*epoch_len + sizeof(epoch->epoch)];
     u_int32_t j;
 
-    fprintf(stdout, "\t[epoch %u @ %u]\n", i, epoch->epoch);
+    fprintf(stdout, "\t[epoch %u @ %llu]\n", i, (long long unsigned int)epoch->epoch);
 
     for(j=0; j<rank->header.max_num_entries; j++) {
       fprintf(stdout, "\t\t[%2d] %u - %llu\n", j,
@@ -2351,7 +2351,7 @@ u_int16_t ndpi_ranking_add_epoch(ndpi_ranking *rank,
 
   qsort(entries, num_epoch_entries, sizeof(ndpi_ranking_epoch_entry), _comp);
 
-  epoch_len = (sizeof(ndpi_ranking_epoch_entry) * rank->header.max_num_entries) + sizeof(u_int32_t /* epoch */);
+  epoch_len = (sizeof(ndpi_ranking_epoch_entry) * rank->header.max_num_entries) + sizeof(this_epoch->epoch);
   offset = epoch_len * rank->header.next_epoch_id;
   this_epoch = (ndpi_ranking_epoch*)&rank->epochs[offset];
 

src/lib/protocols/blizzard.c

@@ -52,11 +52,14 @@ static void search_blizzard_tcp(struct ndpi_detection_module_struct* ndpi_struct
   }
 
   /* Pattern found on Hearthstone */
-  if(packet->payload_packet_len >= 8 &&
-     le32toh(*(uint32_t *)&packet->payload[4]) == (u_int32_t)(packet->payload_packet_len - 8)) {
-    NDPI_LOG_INFO(ndpi_struct, "Found Blizzard (Hearthstone)\n");
-    ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_BLIZZARD, NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
-    return;
+  if(packet->payload_packet_len >= 8) {
+    uint32_t pdu_length;
+    memcpy(&pdu_length, &packet->payload[4], sizeof(pdu_length));
+    if (le32toh(pdu_length) == (u_int32_t)(packet->payload_packet_len - 8)) {
+      NDPI_LOG_INFO(ndpi_struct, "Found Blizzard (Hearthstone)\n");
+      ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_BLIZZARD, NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
+      return;
+    }
   }
 
   /* Pattern found on WoW */

src/lib/protocols/dns.c

@@ -160,7 +160,12 @@ static u_int16_t checkDNSSubprotocol(u_int16_t sport, u_int16_t dport) {
 /* *********************************************** */
 
 static u_int16_t get16(u_int *i, const u_int8_t *payload) {
-  u_int16_t v = *(u_int16_t*)&payload[*i];
+  u_int16_t v;
+
+  if (*i % 2 == 0)
+    v = *(u_int16_t*)&payload[*i];
+  else
+    memcpy(&v, &payload[*i], sizeof(v));
 
   (*i) += 2;
 
@@ -383,7 +388,8 @@ static int process_answers(struct ndpi_detection_module_struct *ndpi_struct,
     }
 
     rsp_type = get16(&x, packet->payload);
-    rsp_ttl  = ntohl(*((u_int32_t*)&packet->payload[x+2]));
+    memcpy(&rsp_ttl, &packet->payload[x+2], sizeof(rsp_ttl));
+    rsp_ttl  = ntohl(rsp_ttl);
 
     if(rsp_ttl == 0)
       ndpi_set_risk(ndpi_struct, flow, NDPI_MINOR_ISSUES, "DNS Record with zero TTL");
@@ -400,7 +406,9 @@ static int process_answers(struct ndpi_detection_module_struct *ndpi_struct,
 
     /* x points to the response "class" field */
     if((x+12) <= packet->payload_packet_len) {
-      u_int32_t ttl = ntohl(*((u_int32_t*)&packet->payload[x+2]));
+      u_int32_t ttl;
+      memcpy(&ttl, &packet->payload[x+2], sizeof(ttl));
+      ttl = ntohl(ttl);
 
       x += 6;
       data_len = get16(&x, packet->payload);

src/lib/protocols/mudfish.c

@@ -77,12 +77,14 @@ static void ndpi_search_mudfish(struct ndpi_detection_module_struct *ndpi_struct
   }
 
   // Check discovery response
-  if (packet->payload_packet_len > 8 &&
-      get_u_int32_t(packet->payload, 0) == htonl(0x554e2041) &&
-      get_u_int32_t(packet->payload, 0) == htonl(0x465f494e))
-  {
-    ndpi_int_mudfish_add_connection(ndpi_struct, flow);
-    return;
+  if (packet->payload_packet_len > 8) {
+    u_int32_t sig;
+    memcpy(&sig, &packet->payload[0], sizeof(sig));
+    if (sig == htonl(0x554e2041) && sig == htonl(0x465f494e))
+    {
+      ndpi_int_mudfish_add_connection(ndpi_struct, flow);
+      return;
+    }
   }
 
   NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

src/lib/protocols/stun.c

@@ -398,10 +398,14 @@ int is_stun(struct ndpi_detection_module_struct *ndpi_struct,
 
   msg_type = ntohs(*((u_int16_t *)&payload[0]));
   msg_len = ntohs(*((u_int16_t *)&payload[2]));
-  magic_cookie = ntohl(*((u_int32_t *)&payload[4]));
-  transaction_id[0] = ntohl(*((u_int32_t *)&payload[8]));
-  transaction_id[1] = ntohl(*((u_int32_t *)&payload[12]));
-  transaction_id[2] = ntohl(*((u_int32_t *)&payload[16]));
+  memcpy(&magic_cookie, &payload[4], sizeof(magic_cookie));
+  magic_cookie = ntohl(magic_cookie);
+  memcpy(&transaction_id[0], &payload[8], sizeof(transaction_id[0]));
+  transaction_id[0] = ntohl(transaction_id[0]);
+  memcpy(&transaction_id[1], &payload[12], sizeof(transaction_id[1]));
+  transaction_id[1] = ntohl(transaction_id[1]);
+  memcpy(&transaction_id[2], &payload[16], sizeof(transaction_id[2]));
+  transaction_id[2] = ntohl(transaction_id[2]);
 
   /* No magic_cookie on classic-stun */
   /* Let's hope that we don't have anymore classic-stun over TCP */