From a9b7300f6fac43011318554c0b942fa143b8a392 Mon Sep 17 00:00:00 2001
From: Matt Christ <matt@christ.systems>
Date: Fri, 21 May 2021 12:59:30 -0500
Subject: brscan5: init at 1.2.6-0

---
 pkgs/build-support/libredirect/libredirect.c | 81 +++++++++++++++++++++++++++-
 pkgs/build-support/libredirect/test.c        |  6 +++
 2 files changed, 85 insertions(+), 2 deletions(-)

(limited to 'pkgs/build-support')

diff --git a/pkgs/build-support/libredirect/libredirect.c b/pkgs/build-support/libredirect/libredirect.c
index c8d6956a6bfe..dfa2978e9f44 100644
--- a/pkgs/build-support/libredirect/libredirect.c
+++ b/pkgs/build-support/libredirect/libredirect.c
@@ -9,6 +9,7 @@
 #include <limits.h>
 #include <string.h>
 #include <spawn.h>
+#include <dirent.h>
 
 #define MAX_REDIRECTS 128
 
@@ -189,9 +190,85 @@ int posix_spawnp(pid_t * pid, const char * file,
     return posix_spawnp_real(pid, rewrite(file, buf), file_actions, attrp, argv, envp);
 }
 
-int execv(const char *path, char *const argv[])
+int execv(const char * path, char * const argv[])
 {
-    int (*execv_real) (const char *path, char *const argv[]) = dlsym(RTLD_NEXT, "execv");
+    int (*execv_real) (const char * path, char * const argv[]) = dlsym(RTLD_NEXT, "execv");
     char buf[PATH_MAX];
     return execv_real(rewrite(path, buf), argv);
 }
+
+int execvp(const char * path, char * const argv[])
+{
+    int (*_execvp) (const char *, char * const argv[]) = dlsym(RTLD_NEXT, "execvp");
+    char buf[PATH_MAX];
+    return _execvp(rewrite(path, buf), argv);
+}
+
+int execve(const char * path, char * const argv[], char * const envp[])
+{
+    int (*_execve) (const char *, char * const argv[], char * const envp[]) = dlsym(RTLD_NEXT, "execve");
+    char buf[PATH_MAX];
+    return _execve(rewrite(path, buf), argv, envp);
+}
+
+DIR * opendir(const char * path)
+{
+    char buf[PATH_MAX];
+    DIR * (*_opendir) (const char*) = dlsym(RTLD_NEXT, "opendir");
+
+    return _opendir(rewrite(path, buf));
+}
+
+#define SYSTEM_CMD_MAX 512
+
+char *replace_substring(char * source, char * buf, char * replace_string, char * start_ptr, char * suffix_ptr) {
+    char head[SYSTEM_CMD_MAX] = {0};
+    strncpy(head, source, start_ptr - source);
+
+    char tail[SYSTEM_CMD_MAX] = {0};
+    if(suffix_ptr < source + strlen(source)) {
+       strcpy(tail, suffix_ptr);
+    }
+
+    sprintf(buf, "%s%s%s", head, replace_string, tail);
+    return buf;
+}
+
+char *replace_string(char * buf, char * from, char * to) {
+    int num_matches = 0;
+    char * matches[SYSTEM_CMD_MAX];
+    int from_len = strlen(from);
+    for(int i=0; i<strlen(buf); i++){
+       char *cmp_start = buf + i;
+       if(strncmp(from, cmp_start, from_len) == 0){
+          matches[num_matches] = cmp_start;
+          num_matches++;
+       }
+    }
+    int len_diff = strlen(to) - strlen(from);
+    for(int n = 0; n < num_matches; n++) {
+       char replaced[SYSTEM_CMD_MAX];
+       replace_substring(buf, replaced, to, matches[n], matches[n]+from_len);
+       strcpy(buf, replaced);
+       for(int nn = n+1; nn < num_matches; nn++) {
+          matches[nn] += len_diff;
+       }
+    }
+    return buf;
+}
+
+void rewriteSystemCall(const char * command, char * buf) {
+    strcpy(buf, command);
+    for (int n = 0; n < nrRedirects; ++n) {
+       replace_string(buf, from[n], to[n]);
+    }
+}
+
+int system(const char *command)
+{
+    int (*_system) (const char*) = dlsym(RTLD_NEXT, "system");
+
+    char newCommand[SYSTEM_CMD_MAX];
+    rewriteSystemCall(command, newCommand);
+    return _system(newCommand);
+}
diff --git a/pkgs/build-support/libredirect/test.c b/pkgs/build-support/libredirect/test.c
index b57664db3c19..722d1303771c 100644
--- a/pkgs/build-support/libredirect/test.c
+++ b/pkgs/build-support/libredirect/test.c
@@ -2,6 +2,7 @@
 #include <fcntl.h>
 #include <spawn.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <unistd.h>
 
 #include <sys/stat.h>
@@ -31,6 +32,10 @@ void test_execv(void) {
     assert(execv(TESTPATH, argv) == 0);
 }
 
+void test_system(void) {
+    assert(system(TESTPATH) == 0);
+}
+
 int main(void)
 {
     FILE *testfp;
@@ -50,6 +55,7 @@ int main(void)
     assert(stat(TESTPATH, &testsb) != -1);
 
     test_spawn();
+    test_system();
     test_execv();
 
     /* If all goes well, this is never reached because test_execv() replaces
-- 
cgit 1.4.1