Implement fd filter and read/write actions

* basic_actions.c (apply_read, apply_write): New functions.
* basic_filters.c (parse_fd_filter, run_fd_filter, free_fd_filter): Likewise.
* defs.h (QUAL_READ, QUAL_WRITE): Add new flags.
(dump_read, dump_write): Add macros for these flags.
* filter.c (filter_types): Add fd filter type.
* filter.h (DECL_FILTER): Add fd filter declaration.
(DECL_FILTER_ACTION): Add read and write filter action declarations.
* filter_action.c (action_types): Add read and write filter action types.
* filter_qualify.c (read_set, write_set): Remove set variables.
(qualify_read, qualify_write): Use new filtering API.
* number_set.h (read_set, write_set): Remove set variable declarations.
* syscall.c (dumpio): Check dump_read, dump_write macros
instead of global sets.

[ldv: simplify *_qualify_mode]
[ldv: cleanup run_fd_filter]

9 files changed, 59 insertions, 22 deletions

diff --git a/basic_actions.c b/basic_actions.c
index d07dcea04..3047c28c9 100644
--- a/basic_actions.c
+++ b/basic_actions.c
@@ -110,3 +110,15 @@ parse_fault(const char *str)
 {
 	return parse_inject_common(str, true, "fault");
 }
+
+void
+apply_read(struct tcb *tcp, void *_priv_data)
+{
+	tcp->qual_flg |= QUAL_READ;
+}
+
+void
+apply_write(struct tcb *tcp, void *_priv_data)
+{
+	tcp->qual_flg |= QUAL_WRITE;
+}
diff --git a/basic_filters.c b/basic_filters.c
index a7ed571f8..a83290731 100644
--- a/basic_filters.c
+++ b/basic_filters.c
@@ -333,3 +333,26 @@ qualify_tokens(const char *const str, struct number_set *const set,
 	if (number < 0)
 		error_msg_and_die("invalid %s '%s'", name, str);
 }
+
+void *
+parse_fd_filter(const char *str)
+{
+	struct number_set *set = alloc_number_set_array(1);
+	qualify_tokens(str, set, string_to_uint, "descriptor");
+	return set;
+}
+
+bool
+run_fd_filter(struct tcb *tcp, void *priv_data)
+{
+	int fd = tcp->u_arg[0];
+
+	return fd < 0 ? false : is_number_in_set(fd, priv_data);
+}
+
+void
+free_fd_filter(void *priv_data)
+{
+	free_number_set_array(priv_data, 1);
+	return;
+}
diff --git a/defs.h b/defs.h
index a13b01174..0482e7f47 100644
--- a/defs.h
+++ b/defs.h
@@ -268,6 +268,8 @@ struct tcb {
 #define QUAL_VERBOSE	0x004	/* decode the structures of this syscall */
 #define QUAL_RAW	0x008	/* print all args in hex for this syscall */
 #define QUAL_INJECT	0x010	/* tamper with this system call on purpose */
+#define QUAL_READ	0x020	/* dump data read in this syscall */
+#define QUAL_WRITE	0x040	/* dump data written in this syscall */
 
 #define DEFAULT_QUAL_FLAGS (QUAL_TRACE | QUAL_ABBREV | QUAL_VERBOSE)
 
@@ -277,6 +279,8 @@ struct tcb {
 #define traced(tcp)	((tcp)->qual_flg & QUAL_TRACE)
 #define verbose(tcp)	((tcp)->qual_flg & QUAL_VERBOSE)
 #define abbrev(tcp)	((tcp)->qual_flg & QUAL_ABBREV)
+#define dump_read(tcp)	((tcp)->qual_flg & QUAL_READ)
+#define dump_write(tcp)	((tcp)->qual_flg & QUAL_WRITE)
 #define raw(tcp)	((tcp)->qual_flg & QUAL_RAW)
 #define inject(tcp)	((tcp)->qual_flg & QUAL_INJECT)
 #define filtered(tcp)	((tcp)->flags & TCB_FILTERED)
diff --git a/filter.c b/filter.c
index 9ac00356a..0c10ba030 100644
--- a/filter.c
+++ b/filter.c
@@ -40,6 +40,7 @@ static const struct filter_type {
 	void (*free_priv_data)(void *);
 } filter_types[] = {
 	FILTER_TYPE(syscall),
+	FILTER_TYPE(fd),
 };
 #undef FILTER_TYPE
 
diff --git a/filter.h b/filter.h
index 0bc4be8b9..f88a7192a 100644
--- a/filter.h
+++ b/filter.h
@@ -76,6 +76,7 @@ free_ ## name ## _filter(void *)					\
 /* End of DECL_FILTER definition. */
 
 DECL_FILTER(syscall);
+DECL_FILTER(fd);
 #undef DECL_FILTER
 
 #define DECL_FILTER_ACTION(name)					\
@@ -89,6 +90,8 @@ DECL_FILTER_ACTION(abbrev);
 DECL_FILTER_ACTION(verbose);
 DECL_FILTER_ACTION(inject);
 DECL_FILTER_ACTION(fault);
+DECL_FILTER_ACTION(read);
+DECL_FILTER_ACTION(write);
 #undef DECL_FILTER_ACTION
 
 #define DECL_FILTER_ACTION_PARSER(name)					\
diff --git a/filter_action.c b/filter_action.c
index c404a2094..20cb9cfc4 100644
--- a/filter_action.c
+++ b/filter_action.c
@@ -47,6 +47,8 @@ static const struct filter_action_type {
 	FILTER_ACTION_TYPE(raw,		2, QUAL_RAW,		NULL,	is_traced),
 	FILTER_ACTION_TYPE(abbrev,	2, QUAL_ABBREV,		NULL,	is_traced),
 	FILTER_ACTION_TYPE(verbose,	2, QUAL_VERBOSE,	NULL,	is_traced),
+	FILTER_ACTION_TYPE(read,	2, QUAL_READ,		NULL,	is_traced),
+	FILTER_ACTION_TYPE(write,	2, QUAL_WRITE,		NULL,	is_traced),
 };
 #undef FILTER_ACTION_TYPE
 
diff --git a/filter_qualify.c b/filter_qualify.c
index 809a1ee45..37012db9d 100644
--- a/filter_qualify.c
+++ b/filter_qualify.c
@@ -33,8 +33,6 @@
 #include "delay.h"
 #include "retval.h"
 
-struct number_set *read_set;
-struct number_set *write_set;
 struct number_set *signal_set;
 
 static int
@@ -252,22 +250,6 @@ parse_inject_common_args(char *const str, struct inject_opts *const opts,
 }
 
 static void
-qualify_read(const char *const str)
-{
-	if (!read_set)
-		read_set = alloc_number_set_array(1);
-	qualify_tokens(str, read_set, string_to_uint, "descriptor");
-}
-
-static void
-qualify_write(const char *const str)
-{
-	if (!write_set)
-		write_set = alloc_number_set_array(1);
-	qualify_tokens(str, write_set, string_to_uint, "descriptor");
-}
-
-static void
 qualify_signals(const char *const str)
 {
 	if (!signal_set)
@@ -287,6 +269,18 @@ qualify_filter(const char *const str, const char *const action_name,
 }
 
 static void
+qualify_read(const char *const str)
+{
+	qualify_filter(str, "read", "fd");
+}
+
+static void
+qualify_write(const char *const str)
+{
+	qualify_filter(str, "write", "fd");
+}
+
+static void
 qualify_trace(const char *const str)
 {
 	qualify_filter(str, "trace", "syscall");
diff --git a/number_set.h b/number_set.h
index ec53bc1b6..f3b9f312c 100644
--- a/number_set.h
+++ b/number_set.h
@@ -59,8 +59,6 @@ alloc_number_set_array(unsigned int nmemb) ATTRIBUTE_MALLOC;
 extern void
 free_number_set_array(struct number_set *, unsigned int nmemb);
 
-extern struct number_set *read_set;
-extern struct number_set *write_set;
 extern struct number_set *signal_set;
 
 #endif /* !STRACE_NUMBER_SET_H */
diff --git a/syscall.c b/syscall.c
index aad9aa4c0..df19b7585 100644
--- a/syscall.c
+++ b/syscall.c
@@ -386,7 +386,7 @@ dumpio(struct tcb *tcp)
 	if (fd < 0)
 		return;
 
-	if (is_number_in_set(fd, write_set)) {
+	if (dump_write(tcp)) {
 		switch (tcp->s_ent->sen) {
 		case SEN_write:
 		case SEN_pwrite:
@@ -413,7 +413,7 @@ dumpio(struct tcb *tcp)
 	if (syserror(tcp))
 		return;
 
-	if (is_number_in_set(fd, read_set)) {
+	if (dump_read(tcp)) {
 		switch (tcp->s_ent->sen) {
 		case SEN_read:
 		case SEN_pread: