uproctrace

add cmdline to proc_begin
Parent 4f36c1f
Stefan Schuermans

Stefan Schuermans commited on 2020-05-17 13:10:13
Showing 5 changed files, with 148 additions and 1 deletions.

liblwpttr/CMakeLists.txt
View file @ 3c738e3
... ... 
@@ -18,6 +18,8 @@ add_library(
18 18 
   src/cleaner.h
19 19 
   src/event.c
20 20 
   src/macros.h
21 
+  src/stringlist.c
22 
+  src/stringlist.h
21 23 
   src/symlink.c
22 24 
   src/symlink.h
23 25 
   src/timestamp.c
liblwpttr/src/event.c
View file @ 3c738e3
... ... 
@@ -1,5 +1,6 @@
1 1 
 #include <liblwpttr/event.h>
2 2 
 #include "cleaner.h"
3 
+#include "stringlist.h"
3 4 
 #include "symlink.h"
4 5 
 #include "timestamp.h"
5 6
... ... 
@@ -46,6 +47,10 @@ int lwpttr_event_proc_begin(void **data, size_t *size) {
46 47 
   if (symlink_read("/proc/self/cwd", &proc_begin.cwd, cleaner) != 0) {
47 48 
     return -1;
48 49 
   }
50 
+  if (stringlist_read("/proc/self/cmdline", &proc_begin.n_cmdline,
51 
+                      &proc_begin.cmdline, cleaner) != 0) {
52 
+    return -1;
53 
+  }
49 54
50 55 
   struct _Lwproctrace__Event event = LWPROCTRACE__EVENT__INIT;
51 56 
   event.timestamp = &timestamp;
liblwpttr/src/stringlist.c
View file @ 3c738e3
... ... 
@@ -0,0 +1,120 @@
1 
+#include "stringlist.h"
2 
+#include "cleaner.h"
3 
+
4 
+#include <fcntl.h>
5 
+#include <stdlib.h>
6 
+#include <string.h>
7 
+#include <sys/types.h>
8 
+#include <sys/stat.h>
9 
+#include <unistd.h>
10 
+
11 
+/**
12 
+ * @brief read file contents
13 
+ * @param[in] pathname path to file containing zero-terminated string list
14 
+ * @param[out] *size size of file contents
15 
+ * @return pointer to malloc-ed file contents or NULL
16 
+ */
17 
+static char * stringlist_read_file(char const *pathname, size_t *size) {
18 
+  /* it is not possible to get file size before, because this yields zero for
19 
+     files like /proc/self/cmdline */
20 
+  *size = 0;
21 
+  /* open file */
22 
+  int fd = open(pathname, O_RDONLY);
23 
+  if (fd == -1) {
24 
+    return NULL;
25 
+  }
26 
+  /* get initial buffer */
27 
+  size_t sz = 4096;
28 
+  char *data = malloc(sz);
29 
+  if (! data) {
30 
+    close(fd);
31 
+    return NULL;
32 
+  }
33 
+  /* read file contents - potentially iteratively */
34 
+  size_t pos = 0;
35 
+  while (1) {
36 
+    /* read file contents */
37 
+    ssize_t len = read(fd, data + pos, sz - pos);
38 
+    /* error -> cleanup and return failure */
39 
+    if (len < 0) {
40 
+      free(data);
41 
+      close(fd);
42 
+      return NULL;
43 
+    }
44 
+    if (len == 0 ) {
45 
+      /* end of file -> return data */
46 
+      *size = pos;
47 
+      return data;
48 
+    }
49 
+    /* data read -> add to buffer */
50 
+    pos += len;
51 
+    /* buffer full ? -> enlarge */
52 
+    if (pos >= sz) {
53 
+      sz *= 2;
54 
+      char *data2 = realloc(data, sz);
55 
+      /* out of memory ? -> cleanup and return failure */
56 
+      if (! data2) {
57 
+        free(data);
58 
+        close(fd);
59 
+        return NULL;
60 
+      }
61 
+      /* use new buffer */
62 
+      data = data2;
63 
+    }
64 
+  }
65 
+}
66 
+
67 
+/**
68 
+ * @brief make array with pointers to strings
69 
+ * @param[in] data pointer to string list
70 
+ * @param[in] sz size of string list
71 
+ * @param[out] *cnt number of entries in array
72 
+ * @return pointer to malloc-ed array of NULL
73 
+ */
74 
+static char ** stringlist_make_ptrs(char *data, size_t sz, size_t *cnt) {
75 
+  /* count strings */
76 
+  size_t pos = 0;
77 
+  *cnt = 0;
78 
+  while (pos < sz) {
79 
+    pos += strlen(data + pos) + 1;
80 
+    ++*cnt;
81 
+  }
82 
+  /* allocate array for pointers */
83 
+  char **ptrs = malloc(*cnt * sizeof(char *));
84 
+  if (! ptrs) {
85 
+    *cnt = 0;
86 
+    return NULL;
87 
+  }
88 
+  /* fill pointers into array */
89 
+  pos = 0;
90 
+  for (size_t i = 0; i < *cnt; ++i) {
91 
+    ptrs[i] = data + pos;
92 
+    pos += strlen(data + pos) + 1;
93 
+  }
94 
+  return ptrs;
95 
+}
96 
+
97 
+int stringlist_read(char const *pathname, size_t *n, char ***strs,
98 
+                    lwpttr_cleaner_t *cleaner) {
99 
+  *n = 0;
100 
+  *strs = NULL;
101 
+  /* read file contents */
102 
+  size_t sz;
103 
+  char *data = stringlist_read_file(pathname, &sz);
104 
+  if (! data) {
105 
+    lwpttr_cleaner_cleanup(cleaner);
106 
+    return -1;
107 
+  }
108 
+  lwpttr_cleaner_add_ptr(cleaner, data);
109 
+  /* create pointer array */
110 
+  size_t cnt;
111 
+  char **ptrs = stringlist_make_ptrs(data, sz, &cnt);
112 
+  if (! ptrs) {
113 
+    lwpttr_cleaner_cleanup(cleaner);
114 
+    return -1;
115 
+  }
116 
+  lwpttr_cleaner_add_ptr(cleaner, ptrs);
117 
+  *n = cnt;
118 
+  *strs = ptrs;
119 
+  return 0;
120 
+}
liblwpttr/src/stringlist.h
View file @ 3c738e3
... ... 
@@ -0,0 +1,20 @@
1 
+#ifndef LWPTTR_STRINGLIST_H
2 
+#define LWPTTR_STRINGLIST_H
3 
+
4 
+#include "cleaner.h"
5 
+
6 
+#include <stdlib.h>
7 
+
8 
+/**
9 
+ * @brief read string list file
10 
+ * @param[in] pathname path to file containing zero-terminated string list
11 
+ * @param[out] *n number of strings read
12 
+ * @param[out] *strs strings read
13 
+ * @param[in,out] cleaner object, malloc-ed string is added to it
14 
+ * @return 0 on success, -1 on error
15 
+ *         (on error, cleanup is done and cleaner is deallocated)
16 
+ */
17 
+int stringlist_read(char const *pathname, size_t *n, char ***strs,
18 
+                    lwpttr_cleaner_t *cleaner);
19 
+
20 
+#endif /* #ifndef LWPTTR_STRINGLIST_H */
tests/CMakeLists.txt
View file @ 3c738e3
... ... 
@@ -7,7 +7,7 @@ add_test(
7 7 
     > out.proto
8 8 
     LWPTPL_OUTPUT=out.proto \
9 9 
     LD_PRELOAD=${CMAKE_BINARY_DIR}/liblwptpl/liblwptpl.so \
10 
-    /bin/true
10 
+    /bin/true a b 'c d'
11 11 
     ls -l out.proto
12 12 
     protoc --proto_path ${CMAKE_SOURCE_DIR}/liblwpttr lwproctrace.proto \
13 13 
            --decode lwproctrace.event < out.proto
14 14