Handle very large -f files by rejecting them.

[tcpdump] / tcpdump.c

diff --git a/tcpdump.c b/tcpdump.c
index 3ebb437bb48f3bc8faf353c18a8992cc463dc484..8f27ba2a47fbbf80700df196f679449c10e84f28 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -108,6 +108,7 @@ The Regents of the University of California.  All rights reserved.\n";
 #endif /* HAVE_CAP_NG_H */
 #endif /* HAVE_LIBCAP_NG */
 
+#include "netdissect-stdinc.h"
 #include "netdissect.h"
 #include "interface.h"
 #include "addrtoname.h"
@@ -130,7 +131,7 @@ The Regents of the University of California.  All rights reserved.\n";
 #endif
 
 static int Bflag;                      /* buffer size */
-static int Cflag;                      /* rotate dump files after this many bytes */
+static long Cflag;                     /* rotate dump files after this many bytes */
 static int Cflag_count;                        /* Keep track of which file number we're writing */
 static int Dflag;                      /* list available devices and exit */
 /*
@@ -171,26 +172,17 @@ static int infoprint;
 char *program_name;
 
 /* Forwards */
-static void error(const char *, ...)
-     __attribute__((noreturn))
-#ifdef __ATTRIBUTE___FORMAT_OK
-     __attribute__((format (printf, 1, 2)))
-#endif /* __ATTRIBUTE___FORMAT_OK */
-     ;
-static void warning(const char *, ...)
-#ifdef __ATTRIBUTE___FORMAT_OK
-     __attribute__((format (printf, 1, 2)))
-#endif /* __ATTRIBUTE___FORMAT_OK */
-     ;
-static void exit_tcpdump(int) __attribute__((noreturn));
+static void error(FORMAT_STRING(const char *), ...) NORETURN PRINTFLIKE(1, 2);
+static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
+static void exit_tcpdump(int) NORETURN;
 static RETSIGTYPE cleanup(int);
 static RETSIGTYPE child_cleanup(int);
 static void print_version(void);
 static void print_usage(void);
-static void show_tstamp_types_and_exit(pcap_t *, const char *device) __attribute__((noreturn));
-static void show_dlts_and_exit(pcap_t *, const char *device) __attribute__((noreturn));
+static void show_tstamp_types_and_exit(pcap_t *, const char *device) NORETURN;
+static void show_dlts_and_exit(pcap_t *, const char *device) NORETURN;
 #ifdef HAVE_PCAP_FINDALLDEVS
-static void show_devices_and_exit (void) __attribute__((noreturn));
+static void show_devices_and_exit (void) NORETURN;
 #endif
 
 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
@@ -616,11 +608,10 @@ droproot(const char *username, const char *chroot_dir)
 #ifdef HAVE_LIBCAP_NG
                {
                        int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
-                       if (ret < 0) {
-                               fprintf(stderr, "error : ret %d\n", ret);
-                       } else {
+                       if (ret < 0)
+                               error("capng_change_id(): return %d\n", ret);
+                       else
                                fprintf(stderr, "dropped privs to %s\n", username);
-                       }
                }
 #else
                if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
@@ -709,13 +700,15 @@ static char *
 get_next_file(FILE *VFile, char *ptr)
 {
        char *ret;
+       size_t len;
 
        ret = fgets(ptr, PATH_MAX, VFile);
        if (!ret)
                return NULL;
 
-       if (ptr[strlen(ptr) - 1] == '\n')
-               ptr[strlen(ptr) - 1] = '\0';
+       len = strlen (ptr);
+       if (len > 0 && ptr[len - 1] == '\n')
+               ptr[len - 1] = '\0';
 
        return ret;
 }
@@ -869,15 +862,22 @@ read_infile(char *fname)
 {
        register int i, fd, cc;
        register char *cp;
-       struct stat buf;
+       our_statb buf;
 
        fd = open(fname, O_RDONLY|O_BINARY);
        if (fd < 0)
                error("can't open %s: %s", fname, pcap_strerror(errno));
 
-       if (fstat(fd, &buf) < 0)
+       if (our_fstat(fd, &buf) < 0)
                error("can't stat %s: %s", fname, pcap_strerror(errno));
 
+       /*
+        * Reject files whose size doesn't fit into an int; a filter
+        * *that* large will probably be too big.
+        */
+       if (buf.st_size > INT_MAX)
+               error("%s is too large", fname);
+
        cp = malloc((u_int)buf.st_size + 1);
        if (cp == NULL)
                error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
@@ -886,7 +886,8 @@ read_infile(char *fname)
        if (cc < 0)
                error("read %s: %s", fname, pcap_strerror(errno));
        if (cc != buf.st_size)
-               error("short read %s (%d != %d)", fname, cc, (int)buf.st_size);
+               error("short read %s (%d != %d)", fname, (int) cc,
+                   (int)buf.st_size);
 
        close(fd);
        /* replace "# comment" with spaces */
@@ -1032,6 +1033,10 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                if (status < 0)
                        error("%s: Can't set time stamp type: %s",
                              device, pcap_statustostr(status));
+               else if (status > 0)
+                       warning("When trying to set timestamp type '%s' on %s: %s",
+                               pcap_tstamp_type_val_to_name(jflag), device,
+                               pcap_statustostr(status));
        }
 #endif
        status = pcap_activate(pc);
@@ -1046,9 +1051,9 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                        /*
                         * Return an error for our caller to handle.
                         */
-                       pcap_close(pc);
                        snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s\n(%s)",
                            device, pcap_statustostr(status), cp);
+                       pcap_close(pc);
                        return (NULL);
                } else if (status == PCAP_ERROR_PERM_DENIED && *cp != '\0')
                        error("%s: %s\n(%s)", device,