Some functions in libpcap were changed some time ago to take const pointer
arguments rather than non-const pointer arguments and to return a const pointer
value:
the prefix argument to pcap_perror();
the return value of pcap_strerror();
the filter expression argument to pcap_compile() and
pcap_compile_nopcap();
the BPF filter program argument to bpf_image().
This patch makes OpenBSD's libpcap function signatures match those of
tcpdump.org's libpcap in that regard.
Index: bpf_image.c
===================================================================
RCS file: /cvs/src/lib/libpcap/bpf_image.c,v
retrieving revision 1.9
diff -u -r1.9 bpf_image.c
--- bpf_image.c 27 Jan 2004 06:58:02 -0000 1.9
+++ bpf_image.c 31 May 2018 08:04:26 -0000
@@ -35,7 +35,7 @@
char *
bpf_image(p, n)
- struct bpf_insn *p;
+ const struct bpf_insn *p;
int n;
{
int v;
Index: gencode.c
===================================================================
RCS file: /cvs/src/lib/libpcap/gencode.c,v
retrieving revision 1.48
diff -u -r1.48 gencode.c
--- gencode.c 6 Feb 2018 02:55:48 -0000 1.48
+++ gencode.c 31 May 2018 08:04:27 -0000
@@ -275,7 +275,7 @@
int
pcap_compile(pcap_t *p, struct bpf_program *program,
- char *buf, int optimize, bpf_u_int32 mask)
+ const char *buf, int optimize, bpf_u_int32 mask)
{
extern int n_errors;
int len;
@@ -322,7 +322,7 @@
int
pcap_compile_nopcap(int snaplen_arg, int linktype_arg,
struct bpf_program *program,
- char *buf, int optimize, bpf_u_int32 mask)
+ const char *buf, int optimize, bpf_u_int32 mask)
{
extern int n_errors;
int len;
Index: gencode.h
===================================================================
RCS file: /cvs/src/lib/libpcap/gencode.h,v
retrieving revision 1.17
diff -u -r1.17 gencode.h
--- gencode.h 27 Apr 2017 15:46:14 -0000 1.17
+++ gencode.h 31 May 2018 08:04:27 -0000
@@ -200,7 +200,7 @@
struct bpf_insn *icode_to_fcode(struct block *, int *);
int pcap_parse(void);
-void lex_init(char *);
+void lex_init(const char *);
void sappend(struct slist *, struct slist *);
/* XXX */
Index: pcap.c
===================================================================
RCS file: /cvs/src/lib/libpcap/pcap.c,v
retrieving revision 1.23
diff -u -r1.23 pcap.c
--- pcap.c 5 Apr 2018 03:47:27 -0000 1.23
+++ pcap.c 31 May 2018 08:04:28 -0000
@@ -415,7 +415,7 @@
}
void
-pcap_perror(pcap_t *p, char *prefix)
+pcap_perror(pcap_t *p, const char *prefix)
{
fprintf(stderr, "%s: %s\n", prefix, p->errbuf);
}
@@ -531,7 +531,7 @@
/*
* Not all systems have strerror().
*/
-char *
+const char *
pcap_strerror(int errnum)
{
#ifdef HAVE_STRERROR
Index: pcap.h
===================================================================
RCS file: /cvs/src/lib/libpcap/pcap.h,v
retrieving revision 1.19
diff -u -r1.19 pcap.h
--- pcap.h 5 Apr 2018 03:47:27 -0000 1.19
+++ pcap.h 31 May 2018 08:04:28 -0000
@@ -188,16 +188,16 @@
int pcap_setdirection(pcap_t *, pcap_direction_t);
int pcap_getnonblock(pcap_t *, char *);
int pcap_setnonblock(pcap_t *, int, char *);
-void pcap_perror(pcap_t *, char *);
+void pcap_perror(pcap_t *, const char *);
int pcap_inject(pcap_t *, const void *, size_t);
int pcap_sendpacket(pcap_t *, const u_char *, int);
const char *pcap_statustostr(int);
-char *pcap_strerror(int);
+const char *pcap_strerror(int);
char *pcap_geterr(pcap_t *);
-int pcap_compile(pcap_t *, struct bpf_program *, char *, int,
+int pcap_compile(pcap_t *, struct bpf_program *, const char *, int,
bpf_u_int32);
int pcap_compile_nopcap(int, int, struct bpf_program *,
- char *, int, bpf_u_int32);
+ const char *, int, bpf_u_int32);
void pcap_freecode(struct bpf_program *);
int pcap_offline_filter(const struct bpf_program *,
const struct pcap_pkthdr *, const u_char *);
@@ -230,7 +230,7 @@
const char *pcap_lib_version(void);
-char *bpf_image(struct bpf_insn *, int);
+char *bpf_image(const struct bpf_insn *, int);
int pcap_get_selectable_fd(pcap_t *);
Index: scanner.l
===================================================================
RCS file: /cvs/src/lib/libpcap/scanner.l,v
retrieving revision 1.24
diff -u -r1.24 scanner.l
--- scanner.l 9 Jul 2017 15:32:09 -0000 1.24
+++ scanner.l 31 May 2018 08:04:28 -0000
@@ -54,7 +54,7 @@
#undef YY_INPUT
#define YY_INPUT(buf, result, max)\
{\
- char *src = in_buffer;\
+ const char *src = in_buffer;\
int i;\
\
if (*src == 0)\
@@ -73,7 +73,7 @@
extern YYSTYPE yylval;
-static char *in_buffer;
+static const char *in_buffer;
%}
@@ -315,7 +315,7 @@
%%
void
lex_init(buf)
- char *buf;
+ const char *buf;
{
in_buffer = buf;
yyrestart(NULL);
