1 files changed, 158 insertions, 0 deletions
diff --git a/libreport/src/lib/spawn.c b/libreport/src/lib/spawn.c
new file mode 100644
index 00000000..2e09da27
--- /dev/null
+++ b/libreport/src/lib/spawn.c
@@ -0,0 +1,158 @@
+/*
+ * Utility routines.
+ *
+ * Licensed under GPLv2, see file COPYING in this tarball for details.
+ */
+#include "libreport.h"
+
+static char *concat_str_vector(char **strings)
+{
+	if (!strings[0])
+		return xzalloc(1); // returns ""
+
+	unsigned len = 0;
+	char **spp = strings;
+	while (*spp)
+		len += strlen(*spp++) + 1;
+
+	char *result = xmalloc(len);
+
+	char *r = result;
+	spp = strings;
+	while (*spp) {
+		r = stpcpy(r, *spp++);
+		*r++ = ' ';
+	}
+	*--r = '\0';
+
+	return result;
+}
+
+/* Returns pid */
+pid_t fork_execv_on_steroids(int flags,
+		char **argv,
+		int *pipefds,
+		char **env_vec,
+		const char *dir,
+		uid_t uid)
+{
+	pid_t child;
+	/* Reminder: [0] is read end, [1] is write end */
+	int pipe_to_child[2];
+	int pipe_fm_child[2];
+
+	/* Sanitize flags */
+	if (!pipefds)
+		flags &= ~(EXECFLG_INPUT | EXECFLG_OUTPUT);
+
+	if (flags & EXECFLG_INPUT)
+		xpipe(pipe_to_child);
+	if (flags & EXECFLG_OUTPUT)
+		xpipe(pipe_fm_child);
+
+	fflush(NULL);
+	child = fork();
+	if (child == -1) {
+		perror_msg_and_die("fork");
+	}
+	if (child == 0) {
+		/* Child */
+
+		if (dir)
+			xchdir(dir);
+
+		if (flags & EXECFLG_SETGUID) {
+			struct passwd* pw = getpwuid(uid);
+			gid_t gid = pw ? pw->pw_gid : uid;
+			setgroups(1, &gid);
+			xsetregid(gid, gid);
+			xsetreuid(uid, uid);
+		}
+
+		if (env_vec) {
+			/* Note: we use the glibc extension that putenv("var")
+			 * *unsets* $var if "var" string has no '=' */
+			while (*env_vec)
+				putenv(*env_vec++);
+		}
+
+		/* Play with stdio descriptors */
+		if (flags & EXECFLG_INPUT) {
+			xmove_fd(pipe_to_child[0], STDIN_FILENO);
+			close(pipe_to_child[1]);
+		} else if (flags & EXECFLG_INPUT_NUL) {
+			xmove_fd(xopen("/dev/null", O_RDWR), STDIN_FILENO);
+		}
+		if (flags & EXECFLG_OUTPUT) {
+			xmove_fd(pipe_fm_child[1], STDOUT_FILENO);
+			close(pipe_fm_child[0]);
+		} else if (flags & EXECFLG_OUTPUT_NUL) {
+			xmove_fd(xopen("/dev/null", O_RDWR), STDOUT_FILENO);
+		}
+
+		/* This should be done BEFORE stderr redirect */
+		VERB1 {
+			char *r = concat_str_vector(argv);
+			log("Executing: %s", r);
+			free(r);
+		}
+
+		if (flags & EXECFLG_ERR2OUT) {
+			/* Want parent to see errors in the same stream */
+			xdup2(STDOUT_FILENO, STDERR_FILENO);
+		} else if (flags & EXECFLG_ERR_NUL) {
+			xmove_fd(xopen("/dev/null", O_RDWR), STDERR_FILENO);
+		}
+
+		if (flags & EXECFLG_SETSID)
+			setsid();
+
+		execvp(argv[0], argv);
+		if (!(flags & EXECFLG_QUIET))
+			perror_msg("Can't execute '%s'", argv[0]);
+		exit(127); /* shell uses this exit code in this case */
+	}
+
+	if (flags & EXECFLG_INPUT) {
+		close(pipe_to_child[0]);
+		pipefds[1] = pipe_to_child[1];
+	}
+	if (flags & EXECFLG_OUTPUT) {
+		close(pipe_fm_child[1]);
+		pipefds[0] = pipe_fm_child[0];
+	}
+
+	return child;
+}
+
+char *run_in_shell_and_save_output(int flags,
+		const char *cmd,
+		const char *dir,
+		size_t *size_p)
+{
+	flags |= EXECFLG_OUTPUT;
+	flags &= ~EXECFLG_INPUT;
+
+	const char *argv[] = { "/bin/sh", "-c", cmd, NULL };
+	int pipeout[2];
+	pid_t child = fork_execv_on_steroids(flags, (char **)argv, pipeout,
+		/*env_vec:*/ NULL, dir, /*uid (unused):*/ 0);
+
+	size_t pos = 0;
+	char *result = NULL;
+	while (1) {
+		result = (char*) xrealloc(result, pos + 4*1024 + 1);
+		size_t sz = safe_read(pipeout[0], result + pos, 4*1024);
+		if (sz <= 0) {
+			break;
+		}
+		pos += sz;
+	}
+	result[pos] = '\0';
+	if (size_p)
+		*size_p = pos;
+	close(pipeout[0]);
+	waitpid(child, NULL, 0);
+
+	return result;
+}