gboolean bitfields considered harmful

ISO C Std § 6.7.2, 5: "for bit-fields, it is implementation-defined
whether the specifier int designates the same type as signed int or the
same type as unsigned int." (See also the note in § 6.7.2.1 and ISO C
Std Appendix J.3.9.)

A gboolean is a typedef'd gint. Therefore, many implementations,
including gcc and clang, treat a gboolean bitfield of width 1 as
signed, meaning that it has two possible values: 0 and -1, any time
the integer promotions occur (which is all the time.) Constructs like this:

        dgram_info->from_server = TRUE;
        if (dgram_info->from_server == TRUE) ws_warning("True");

will not work as expected, though gcc (but not clang) will give an
error:

/home/johnthacker/wireshark/epan/dissectors/packet-quic.c:3457:37: error: comparison is always false due to limited range of data type [-Werror=type-limits]
 3457 |         if (dgram_info->from_server == TRUE)
      |

        proto_tree_add_debug_text(quic_tree, "Connection: %d %p from_server:%d", pinfo->num, dgram_info->conn, dgram_info->from_server);

Connection: 1 0x7fc4b47f2be0 from_server:0
Connection: 2 0x7fc4b47f2be0 from_server:-1
Connection: 3 0x7fc4b47f2be0 from_server:0
Connection: 4 0x7fc4b47f2be0 from_server:-1

At worst this can cause buffer overruns.

If a bitfield is desired, to guarantee expected behavior the standard
_Bool/bool should be used instead.

3 files changed, 22 insertions, 18 deletions

diff --git a/epan/dissectors/packet-quic.c b/epan/dissectors/packet-quic.c
index 526a91240e..96e00cb2cd 100644
--- a/epan/dissectors/packet-quic.c
+++ b/epan/dissectors/packet-quic.c
@@ -48,6 +48,8 @@
 
 #include <config.h>
 
+#include <stdbool.h>
+
 #include <epan/packet.h>
 #include <epan/expert.h>
 #include <epan/proto_data.h>
@@ -346,7 +348,7 @@ typedef struct quic_pp_state {
     quic_pp_cipher  pp_ciphers[2];  /**< PP cipher for Key Phase 0/1 */
     quic_hp_cipher  hp_cipher;      /**< HP cipher for both Key Phases; it does not change after KeyUpdate */
     guint64         changed_in_pkn; /**< Packet number where key change occurred. */
-    gboolean        key_phase : 1;  /**< Current key phase. */
+    bool            key_phase : 1;  /**< Current key phase. */
 } quic_pp_state_t;
 
 /** Singly-linked list of Connection IDs. */
@@ -402,12 +404,12 @@ typedef struct quic_info_data {
     guint32         version;
     address         server_address;
     guint16         server_port;
-    gboolean        skip_decryption : 1; /**< Set to 1 if no keys are available. */
-    gboolean        client_dcid_set : 1; /**< Set to 1 if client_dcid_initial is set. */
-    gboolean        client_loss_bits_recv : 1; /**< The client is able to read loss bits info */
-    gboolean        client_loss_bits_send : 1; /**< The client wants to send loss bits info */
-    gboolean        server_loss_bits_recv : 1; /**< The server is able to read loss bits info */
-    gboolean        server_loss_bits_send : 1; /**< The server wants to send loss bits info */
+    bool            skip_decryption : 1; /**< Set to 1 if no keys are available. */
+    bool            client_dcid_set : 1; /**< Set to 1 if client_dcid_initial is set. */
+    bool            client_loss_bits_recv : 1; /**< The client is able to read loss bits info */
+    bool            client_loss_bits_send : 1; /**< The client wants to send loss bits info */
+    bool            server_loss_bits_recv : 1; /**< The server is able to read loss bits info */
+    bool            server_loss_bits_send : 1; /**< The server wants to send loss bits info */
     int             hash_algo;      /**< Libgcrypt hash algorithm for key derivation. */
     int             cipher_algo;    /**< Cipher algorithm for packet number and packet encryption. */
     int             cipher_mode;    /**< Cipher mode for packet encryption. */
@@ -448,8 +450,8 @@ struct quic_packet_info {
     guint8                  pkn_len;        /**< Length of PKN (1/2/3/4) or unknown (0). */
     guint8                  first_byte;     /**< Decrypted flag byte, valid only if pkn_len is non-zero. */
     guint8                  packet_type;
-    gboolean                retry_integrity_failure : 1;
-    gboolean                retry_integrity_success : 1;
+    bool                    retry_integrity_failure : 1;
+    bool                    retry_integrity_success : 1;
 };
 typedef struct quic_packet_info quic_packet_info_t;
 
@@ -457,7 +459,7 @@ typedef struct quic_packet_info quic_packet_info_t;
 typedef struct quic_datagram {
     quic_info_data_t       *conn;
     quic_packet_info_t      first_packet;
-    gboolean                from_server : 1;
+    bool                    from_server : 1;
 } quic_datagram;
 
 /**
diff --git a/epan/dissectors/packet-wireguard.c b/epan/dissectors/packet-wireguard.c
index 32188ae2e9..5b8499130b 100644
--- a/epan/dissectors/packet-wireguard.c
+++ b/epan/dissectors/packet-wireguard.c
@@ -16,6 +16,7 @@
 #include <config.h>
 
 #include <errno.h>
+#include <stdbool.h>
 
 #define WS_LOG_DOMAIN "packet-wireguard"
 
@@ -210,8 +211,8 @@ typedef struct {
     const wg_skey_t    *initiator_skey;     /* Spub_i based on Initiation.static (decrypted, null if decryption failed) */
     const wg_skey_t    *responder_skey;     /* Spub_r based on Initiation.MAC1 (+Spriv_r if available) */
     guint8              timestamp[12];      /* Initiation.timestamp (decrypted) */
-    gboolean            timestamp_ok : 1;   /* Whether the timestamp was successfully decrypted */
-    gboolean            empty_ok : 1;       /* Whether the empty field was successfully decrypted */
+    bool                timestamp_ok : 1;   /* Whether the timestamp was successfully decrypted */
+    bool                empty_ok : 1;       /* Whether the empty field was successfully decrypted */
 
     /* The following fields are only valid on the initial pass. */
     const wg_ekey_t    *initiator_ekey;     /* Epub_i matching Initiation.Ephemeral (+Epriv_i if available) */
diff --git a/ui/tap-sctp-analysis.h b/ui/tap-sctp-analysis.h
index eb5ecf101e..0f7f1ebc4e 100644
--- a/ui/tap-sctp-analysis.h
+++ b/ui/tap-sctp-analysis.h
@@ -12,6 +12,7 @@
 #ifndef __TAP_SCTP_ANALYSIS_H__
 #define __TAP_SCTP_ANALYSIS_H__
 
+#include <stdbool.h>
 #include <epan/dissectors/packet-sctp.h>
 #include <epan/address.h>
 #ifdef _WIN32
@@ -165,8 +166,8 @@ typedef struct _sctp_init_collision {
 	guint32 initack_vtag;		/* initiate tag of the INIT-ACK chunk */
 	guint32 init_min_tsn;		/* initial tsn of the INIT chunk */
 	guint32 initack_min_tsn;	/* initial tsn of the INIT-ACK chunk */
-	gboolean init:1;
-	gboolean initack:1;
+	bool    init:1;
+	bool    initack:1;
 } sctp_init_collision_t;
 
 struct tsn_sort{
@@ -232,10 +233,10 @@ typedef struct _sctp_assoc_info {
 	guint32	   max_window2;
 	guint32	   arwnd1;
 	guint32	   arwnd2;
-	gboolean   init:1;
-	gboolean   initack:1;
-	gboolean   firstdata:1;
-	gboolean   init_collision:1;
+	bool       init:1;
+	bool       initack:1;
+	bool       firstdata:1;
+	bool       init_collision:1;
 	guint16	   initack_dir;
 	guint16	   direction;
 	guint32	   min_secs;