On UN*X, always use sigaction(), and always have signal handlers return void.

[tcpdump] / tcpdump.c

diff --git a/tcpdump.c b/tcpdump.c
index 0d6ff7830d690a3c40dd2f29ae3d0abc997e2498..65b7e76950a0fcb58b795f26652bba265309968b 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -122,7 +122,6 @@ The Regents of the University of California.  All rights reserved.\n";
 #include "interface.h"
 #include "addrtoname.h"
 #include "machdep.h"
-#include "setsignal.h"
 #include "gmt2local.h"
 #include "pcap-missing.h"
 #include "ascii_strcasecmp.h"
@@ -192,8 +191,9 @@ cap_channel_t *capdns;
 static NORETURN void error(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
 static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
 static NORETURN void exit_tcpdump(int);
-static RETSIGTYPE cleanup(int);
-static RETSIGTYPE child_cleanup(int);
+static void (*setsignal (int sig, void (*func)(int)))(int);
+static void cleanup(int);
+static void child_cleanup(int);
 static void print_version(void);
 static void print_usage(void);
 static NORETURN void show_tstamp_types_and_exit(pcap_t *, const char *device);
@@ -208,7 +208,7 @@ static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 static void droproot(const char *, const char *);
 
 #ifdef SIGNAL_REQ_INFO
-RETSIGTYPE requestinfo(int);
+void requestinfo(int);
 #endif
 
 #if defined(USE_WIN32_MM_TIMER)
@@ -1191,7 +1191,7 @@ main(int argc, char **argv)
        const char *dlt_name;
        struct bpf_program fcode;
 #ifndef _WIN32
-       RETSIGTYPE (*oldhandler)(int);
+       void (*oldhandler)(int);
 #endif
        struct dump_info dumpinfo;
        u_char *pcap_userdata;
@@ -2082,7 +2082,7 @@ main(int argc, char **argv)
        if (ndo->ndo_vflag > 0 && WFileName && !print) {
                /*
                 * When capturing to a file, if "--print" wasn't specified,
-                *"-v" means tcpdump should, every 10 seconds,
+                *"-v" means tcpdump should, once per second,
                 * "v"erbosely report the number of packets captured.
                 */
 #ifdef USE_WIN32_MM_TIMER
@@ -2251,8 +2251,29 @@ main(int argc, char **argv)
        exit_tcpdump(status == -1 ? 1 : 0);
 }
 
+/*
+ * Catch a signal.
+ */
+static void
+(*setsignal (int sig, void (*func)(int)))(int)
+{
+#ifdef _WIN32
+       return (signal(sig, func));
+#else
+       struct sigaction old, new;
+
+       memset(&new, 0, sizeof(new));
+       new.sa_handler = func;
+       if (sig == SIGCHLD)
+               new.sa_flags = SA_RESTART;
+       if (sigaction(sig, &new, &old) < 0)
+               return (SIG_ERR);
+       return (old.sa_handler);
+#endif
+}
+
 /* make a clean exit on interrupts */
-static RETSIGTYPE
+static void
 cleanup(int signo _U_)
 {
 #ifdef USE_WIN32_MM_TIMER
@@ -2297,7 +2318,7 @@ cleanup(int signo _U_)
   waiting a child processes to die
  */
 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
-static RETSIGTYPE
+static void
 child_cleanup(int signo _U_)
 {
   wait(NULL);
@@ -2684,7 +2705,7 @@ print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 #endif
 
 #ifdef SIGNAL_REQ_INFO
-RETSIGTYPE requestinfo(int signo _U_)
+void requestinfo(int signo _U_)
 {
        if (infodelay)
                ++infoprint;
@@ -2693,6 +2714,18 @@ RETSIGTYPE requestinfo(int signo _U_)
 }
 #endif
 
+static void
+print_packets_captured (void)
+{
+       static u_int prev_packets_captured, first = 1;
+
+       if (infodelay == 0 && (first || packets_captured != prev_packets_captured)) {
+               fprintf(stderr, "Got %u\r", packets_captured);
+               first = 0;
+               prev_packets_captured = packets_captured;
+       }
+}
+
 /*
  * Called once each second in verbose mode while dumping to file
  */
@@ -2700,14 +2733,12 @@ RETSIGTYPE requestinfo(int signo _U_)
 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
                                  DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
 {
-       if (infodelay == 0)
-               fprintf(stderr, "Got %u\r", packets_captured);
+       print_packets_captured();
 }
 #elif defined(HAVE_ALARM)
 static void verbose_stats_dump(int sig _U_)
 {
-       if (infodelay == 0)
-               fprintf(stderr, "Got %u\r", packets_captured);
+       print_packets_captured();
        alarm(1);
 }
 #endif
@@ -2750,6 +2781,9 @@ print_version(void)
        smi_version_string = nd_smi_version_string();
        if (smi_version_string != NULL)
                (void)fprintf (stderr, "SMI-library: %s\n", smi_version_string);
+#ifdef HAVE_DNET_HTOA
+       (void)fprintf(stderr, "libdnet unknown version\n");
+#endif
 
 #if defined(__SANITIZE_ADDRESS__)
        (void)fprintf (stderr, "Compiled with AddressSanitizer/GCC.\n");