Update config.{guess,sub}, timestamps 2023-01-01,2023-01-21

[libpcap] / pcap.c

diff --git a/pcap.c b/pcap.c
index 928f1890eeb7cd8e68f7ddf332944b5fbf9e1926..ef1bbb71f87fed1a4d692db79b44768229f80f48 100644 (file)
--- a/pcap.c
+++ b/pcap.c
@@ -131,8 +131,6 @@ struct rtentry;             /* declarations in <net/if.h> */
 
 #ifdef _WIN32
 /*
- * DllMain(), required when built as a Windows DLL.
- *
  * To quote the WSAStartup() documentation:
  *
  *   The WSAStartup function typically leads to protocol-specific helper
@@ -147,19 +145,12 @@ struct rtentry;           /* declarations in <net/if.h> */
  *   be called from the DllMain function in a application DLL. This can
  *   potentially cause deadlocks.
  *
- * So we don't initialize Winsock here.  pcap_init() should be called
- * to initialize pcap on both UN*X and Windows; it will initialize
- * Winsock on Windows.  (It will also be initialized as needed if
- * pcap_init() hasn't been called.)
+ * So we don't initialize Winsock in a DllMain() routine.
+ *
+ * pcap_init() should be called to initialize pcap on both UN*X and
+ * Windows; it will initialize Winsock on Windows.  (It will also be
+ * initialized as needed if pcap_init() hasn't been called.)
  */
-BOOL WINAPI DllMain(
-  HANDLE hinstDLL _U_,
-  DWORD dwReason _U_,
-  LPVOID lpvReserved _U_
-)
-{
-       return (TRUE);
-}
 
 /*
  * Start Winsock.
@@ -259,7 +250,7 @@ pcap_init(unsigned int opts, char *errbuf)
                        if (pcap_utf_8_mode) {
                                snprintf(errbuf, PCAP_ERRBUF_SIZE,
                                    "Multiple pcap_init calls with different character encodings");
-                               return (-1);
+                               return (PCAP_ERROR);
                        }
                }
                break;
@@ -270,7 +261,7 @@ pcap_init(unsigned int opts, char *errbuf)
                        if (!pcap_utf_8_mode) {
                                snprintf(errbuf, PCAP_ERRBUF_SIZE,
                                    "Multiple pcap_init calls with different character encodings");
-                               return (-1);
+                               return (PCAP_ERROR);
                        }
                }
                pcap_utf_8_mode = 1;
@@ -278,7 +269,7 @@ pcap_init(unsigned int opts, char *errbuf)
 
        default:
                snprintf(errbuf, PCAP_ERRBUF_SIZE, "Unknown options specified");
-               return (-1);
+               return (PCAP_ERROR);
        }
 
        /*
@@ -303,7 +294,7 @@ pcap_init(unsigned int opts, char *errbuf)
         */
        if (internal_wsockinit(errbuf) == -1) {
                /* Failed. */
-               return (-1);
+               return (PCAP_ERROR);
        }
 #endif
 
@@ -622,7 +613,9 @@ pcap_next_ex(pcap_t *p, struct pcap_pkthdr **pkt_header,
                 * Return codes for pcap_offline_read() are:
                 *   -  0: EOF
                 *   - -1: error
-                *   - >1: OK
+                *   - >0: OK - result is number of packets read, so
+                *         it will be 1 in this case, as we've passed
+                *         a maximum packet count of 1
                 * The first one ('0') conflicts with the return code of
                 * 0 from pcap_read() meaning "no packets arrived before
                 * the timeout expired", so we map it to -2 so you can
@@ -641,7 +634,9 @@ pcap_next_ex(pcap_t *p, struct pcap_pkthdr **pkt_header,
         *   -  0: timeout
         *   - -1: error
         *   - -2: loop was broken out of with pcap_breakloop()
-        *   - >1: OK
+        *   - >0: OK, result is number of packets captured, so
+        *         it will be 1 in this case, as we've passed
+        *         a maximum packet count of 1
         * The first one ('0') conflicts with the return code of 0 from
         * pcap_offline_read() meaning "end of file".
        */
@@ -2851,7 +2846,8 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, char *er
 fail:
        if (status == PCAP_ERROR) {
                /*
-                * Another buffer is a bit cumbersome, but it avoids -Wformat-truncation.
+                * Another buffer is a bit cumbersome, but it avoids
+                * -Wformat-truncation.
                 */
                char trimbuf[PCAP_ERRBUF_SIZE - 5]; /* 2 bytes shorter */
 
@@ -2862,16 +2858,27 @@ fail:
            status == PCAP_ERROR_PERM_DENIED ||
            status == PCAP_ERROR_PROMISC_PERM_DENIED) {
                /*
-                * Idem.
+                * Only show the additional message if it's not
+                * empty.
                 */
-               char trimbuf[PCAP_ERRBUF_SIZE - 8]; /* 2 bytes shorter */
+               if (p->errbuf[0] != '\0') {
+                       /*
+                        * Idem.
+                        */
+                       char trimbuf[PCAP_ERRBUF_SIZE - 8]; /* 2 bytes shorter */
 
-               pcap_strlcpy(trimbuf, p->errbuf, sizeof(trimbuf));
-               snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s (%.*s)", device,
-                   pcap_statustostr(status), PCAP_ERRBUF_SIZE - 6, trimbuf);
-       } else
+                       pcap_strlcpy(trimbuf, p->errbuf, sizeof(trimbuf));
+                       snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s (%.*s)",
+                           device, pcap_statustostr(status),
+                           PCAP_ERRBUF_SIZE - 6, trimbuf);
+               } else {
+                       snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s",
+                           device, pcap_statustostr(status));
+               }
+       } else {
                snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", device,
                    pcap_statustostr(status));
+       }
        pcap_close(p);
        return (NULL);
 }
@@ -3362,7 +3369,7 @@ pcap_datalink_val_to_description_or_dlt(int dlt)
         if (description != NULL) {
                 return description;
         } else {
-                (void)snprintf(unkbuf, sizeof(unkbuf), "DLT %u", dlt);
+                (void)snprintf(unkbuf, sizeof(unkbuf), "DLT %d", dlt);
                 return unkbuf;
         }
 }
@@ -3656,7 +3663,7 @@ pcap_statustostr(int errnum)
                return ("That operation is supported only in monitor mode");
 
        case PCAP_ERROR_PERM_DENIED:
-               return ("You don't have permission to capture on that device");
+               return ("You don't have permission to perform this capture on that device");
 
        case PCAP_ERROR_IFACE_NOT_UP:
                return ("That device is not up");
@@ -4085,7 +4092,7 @@ pcap_close(pcap_t *p)
 }
 
 /*
- * Helpers for safely loding code at run time.
+ * Helpers for safely loading code at run time.
  * Currently Windows-only.
  */
 #ifdef _WIN32
@@ -4194,6 +4201,20 @@ pcap_read_dead(pcap_t *p, int cnt _U_, pcap_handler callback _U_,
        return (-1);
 }
 
+static void
+pcap_breakloop_dead(pcap_t *p _U_)
+{
+       /*
+        * A "dead" pcap_t is just a placeholder to use in order to
+        * compile a filter to BPF code or to open a savefile for
+        * writing.  It doesn't support any operations, including
+        * capturing or reading packets, so there will never be a
+        * get-packets loop in progress to break out *of*.
+        *
+        * As such, this routine doesn't need to do anything.
+        */
+}
+
 static int
 pcap_inject_dead(pcap_t *p, const void *buf _U_, int size _U_)
 {
@@ -4407,6 +4428,7 @@ pcap_open_dead_with_tstamp_precision(int linktype, int snaplen, u_int precision)
        p->live_dump_ended_op = pcap_live_dump_ended_dead;
        p->get_airpcap_handle_op = pcap_get_airpcap_handle_dead;
 #endif
+       p->breakloop_op = pcap_breakloop_dead;
        p->cleanup_op = pcap_cleanup_dead;
 
        /*