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authorJari Vetoniemi <mailroxas@gmail.com>2018-10-19 14:35:16 +0300
committerJari Vetoniemi <mailroxas@gmail.com>2018-10-19 15:13:07 +0300
commit743fb001f3d381b14d48f3fdfc9ee648a7c0644c (patch)
treee46f65bfac59427b1389a4fb5d8c13ca34ed1c69 /src/io/io-ptrace.c
parent6cb8c44fef192f3f8e7164d9c3baccacc9db620c (diff)
Refactor project, offer uio variant of region-rw
Diffstat (limited to 'src/io/io-ptrace.c')
-rw-r--r--src/io/io-ptrace.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/src/io/io-ptrace.c b/src/io/io-ptrace.c
new file mode 100644
index 0000000..50d0766
--- /dev/null
+++ b/src/io/io-ptrace.c
@@ -0,0 +1,82 @@
+#include "io.h"
+#include <stdio.h>
+#include <err.h>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+
+static size_t
+io_ptrace_do(const struct io *io, void *ptr, const size_t offset, const size_t size, size_t (*iofun)(void*, size_t, size_t, FILE*))
+{
+ if (fseek(io->backing, offset, SEEK_SET) != 0) {
+ warn("fseek(/proc/%u/mem, %zu)", io->pid, offset);
+ return 0;
+ }
+
+ return iofun(ptr, 1, size, io->backing);
+}
+
+static size_t
+io_ptrace_write(const struct io *io, const void *ptr, const size_t offset, const size_t size)
+{
+ clearerr(io->backing);
+ const size_t ret = io_ptrace_do(io, (void*)ptr, offset, size, (size_t(*)())fwrite);
+
+ if (ferror(io->backing))
+ warn("fwrite(/proc/%u/mem)", io->pid);
+
+ return ret;
+}
+
+static size_t
+io_ptrace_read(const struct io *io, void *ptr, const size_t offset, const size_t size)
+{
+ clearerr(io->backing);
+ const size_t ret = io_ptrace_do(io, ptr, offset, size, fread);
+
+ if (ferror(io->backing))
+ warn("fread(/proc/%u/mem)", io->pid);
+
+ return ret;
+}
+
+static void
+io_ptrace_cleanup(struct io *io)
+{
+ if (io->backing)
+ fclose(io->backing);
+
+ if (io->pid)
+ ptrace(PTRACE_DETACH, io->pid, 1, 0);
+}
+
+bool
+io_ptrace_init(struct io *io, const pid_t pid)
+{
+ *io = (struct io){ .pid = pid, .read = io_ptrace_read, .write = io_ptrace_write, .cleanup = io_ptrace_cleanup };
+
+ if (ptrace(PTRACE_ATTACH, pid, NULL, NULL) == -1L) {
+ warn("ptrace(PTRACE_ATTACH, %u, NULL, NULL)", pid);
+ goto fail;
+ }
+
+ {
+ int status;
+ if (waitpid(pid, &status, 0) == -1 || !WIFSTOPPED(status)) {
+ warn("waitpid(%u) == %d", pid, status);
+ goto fail;
+ }
+ }
+
+ char path[128];
+ snprintf(path, sizeof(path), "/proc/%u/mem", pid);
+ if (!(io->backing = fopen(path, "w+b"))) {
+ warn("fopen(%s)", path);
+ goto fail;
+ }
+
+ return true;
+
+fail:
+ io->cleanup(io);
+ return false;
+}