commit: 56905522dfd178685b6225c6be89560cb02c445c
Author: Mike Frysinger <vapier <AT> gentoo <DOT> org>
AuthorDate: Mon Jun 20 00:37:04 2016 +0000
Commit: Mike Frysinger <vapier <AT> gentoo <DOT> org>
CommitDate: Mon Jun 20 00:37:04 2016 +0000
URL: https://gitweb.gentoo.org/proj/pax-utils.git/commit/?id=56905522
pspax: rewrite core loop to use *at funcs
This makes the code a bit simpler & robust.
pspax.c | 228 ++++++++++++++++++++++++++++++++++++----------------------------
1 file changed, 128 insertions(+), 100 deletions(-)
diff --git a/pspax.c b/pspax.c
index c64472c..67b7678 100644
--- a/pspax.c
+++ b/pspax.c
@@ -40,20 +40,47 @@ static pid_t show_pid = 0;
static uid_t show_uid = (uid_t)-1;
static gid_t show_gid = (gid_t)-1;
-static FILE *proc_fopen(pid_t pid, const char *file)
+static int proc_open(int pfd, const char *file)
{
- char path[__PAX_UTILS_PATH_MAX];
- snprintf(path, sizeof(path), PROC_DIR "/%u/%s", pid, file);
- path[sizeof(path) - 1] = '\0';
- return fopen(path, "r");
+ return openat(pfd, file, O_RDONLY|O_CLOEXEC);
}
-static char *get_proc_name_cmdline(pid_t pid)
+static FILE *proc_fopen(int pfd, const char *file)
+{
+ int fd;
+ FILE *fp;
+
+ fd = proc_open(pfd, file);
+ if (fd == -1)
+ return NULL;
+
+ fp = fdopen(fd, "re");
+ if (fp == NULL)
+ close(fd);
+
+ return fp;
+}
+
+static elfobj *proc_readelf(int pfd)
+{
+ int fd;
+ elfobj *elf;
+
+ fd = proc_open(pfd, "exe");
+ if (fd == -1)
+ return NULL;
+
+ elf = readelf_fd("proc/exe", fd, 0);
+ close(fd);
+ return elf;
+}
+
+static char *get_proc_name_cmdline(int pfd)
{
FILE *fp;
static char str[1024];
- fp = proc_fopen(pid, "cmdline");
+ fp = proc_fopen(pfd, "cmdline");
if (fp == NULL)
return NULL;
@@ -64,15 +91,15 @@ static char *get_proc_name_cmdline(pid_t pid)
return (str);
}
-static char *get_proc_name(pid_t pid)
+static char *get_proc_name(int pfd)
{
FILE *fp;
static char str[BUFSIZ];
if (wide_output)
- return get_proc_name_cmdline(pid);
+ return get_proc_name_cmdline(pfd);
- fp = proc_fopen(pid, "stat");
+ fp = proc_fopen(pfd, "stat");
if (fp == NULL)
return NULL;
@@ -90,12 +117,12 @@ static char *get_proc_name(pid_t pid)
return (str+1);
}
-static int get_proc_maps(pid_t pid)
+static int get_proc_maps(int pfd)
{
FILE *fp;
static char str[BUFSIZ];
- if ((fp = proc_fopen(pid, "maps")) == NULL)
+ if ((fp = proc_fopen(pfd, "maps")) == NULL)
return -1;
while (fgets(str, sizeof(str), fp)) {
@@ -126,12 +153,12 @@ static int get_proc_maps(pid_t pid)
return 0;
}
-static int print_executable_mappings(pid_t pid)
+static int print_executable_mappings(int pfd)
{
FILE *fp;
static char str[BUFSIZ];
- if ((fp = proc_fopen(pid, "maps")) == NULL)
+ if ((fp = proc_fopen(pfd, "maps")) == NULL)
return -1;
while (fgets(str, sizeof(str), fp)) {
@@ -169,28 +196,24 @@ static int print_executable_mappings(pid_t pid)
# define NOTE_TO_SELF
#endif
-static struct passwd *get_proc_passwd(pid_t pid)
+static struct passwd *get_proc_passwd(int pfd)
{
struct stat st;
- struct passwd *pwd;
- char path[__PAX_UTILS_PATH_MAX];
-
- snprintf(path, sizeof(path), PROC_DIR "/%u/stat", pid);
+ struct passwd *pwd = NULL;
- if (stat(path, &st) != -1)
- if ((pwd = getpwuid(st.st_uid)) != NULL)
- return pwd;
+ if (fstatat(pfd, "stat", &st, AT_SYMLINK_NOFOLLOW) != -1)
+ pwd = getpwuid(st.st_uid);
- return NULL;
+ return pwd;
}
-static char *get_proc_status(pid_t pid, const char *name)
+static char *get_proc_status(int pfd, const char *name)
{
FILE *fp;
size_t len;
static char str[BUFSIZ];
- if ((fp = proc_fopen(pid, "status")) == NULL)
+ if ((fp = proc_fopen(pfd, "status")) == NULL)
return NULL;
len = strlen(name);
@@ -208,13 +231,13 @@ static char *get_proc_status(pid_t pid, const char *name)
return NULL;
}
-static char *get_pid_attr(pid_t pid)
+static char *get_pid_attr(int pfd)
{
FILE *fp;
char *p;
static char buf[BUFSIZ];
- if ((fp = proc_fopen(pid, "attr/current")) == NULL)
+ if ((fp = proc_fopen(pfd, "attr/current")) == NULL)
return NULL;
if (fgets(buf, sizeof(buf), fp) != NULL)
@@ -225,13 +248,13 @@ static char *get_pid_attr(pid_t pid)
return buf;
}
-static char *get_pid_addr(pid_t pid)
+static char *get_pid_addr(int pfd)
{
FILE *fp;
char *p;
static char buf[BUFSIZ];
- if ((fp = proc_fopen(pid, "ipaddr")) == NULL)
+ if ((fp = proc_fopen(pfd, "ipaddr")) == NULL)
return NULL;
if (fgets(buf, sizeof(buf), fp) != NULL)
@@ -242,15 +265,15 @@ static char *get_pid_addr(pid_t pid)
return buf;
}
-static const char *get_proc_type(pid_t pid)
+static const char *get_proc_type(int pfd)
{
- char fname[32];
elfobj *elf;
const char *ret;
- snprintf(fname, sizeof(fname), PROC_DIR "/%u/exe", pid);
- if ((elf = readelf(fname)) == NULL)
+ elf = proc_readelf(pfd);
+ if (elf == NULL)
return NULL;
+
ret = get_elfetype(elf);
unreadelf(elf);
return ret;
@@ -290,15 +313,15 @@ static char *scanelf_file_phdr(elfobj *elf)
return ret;
}
/* we scan the elf file two times when the -e flag is given. But we don't need
-e very often so big deal */
-static const char *get_proc_phdr(pid_t pid)
+static const char *get_proc_phdr(int pfd)
{
- char fname[32];
elfobj *elf;
const char *ret;
- snprintf(fname, sizeof(fname), PROC_DIR "/%u/exe", pid);
- if ((elf = readelf(fname)) == NULL)
+ elf = proc_readelf(pfd);
+ if (elf == NULL)
return NULL;
+
ret = scanelf_file_phdr(elf);
unreadelf(elf);
return ret;
@@ -312,9 +335,9 @@ static void pspax(const char *find_name)
pid_t ppid = show_pid;
int have_attr, have_addr, wx;
struct passwd *pwd;
- struct stat st;
const char *pax, *type, *name, *attr, *addr;
char *caps;
+ int pfd;
WRAP_SYSCAP(ssize_t length; cap_t cap_d;)
WRAP_SYSCAP(cap_d = cap_init());
@@ -339,76 +362,81 @@ static void pspax(const char *find_name)
have_addr ? "IPADDR" : "", show_phdr ? "STACK LOAD" :
"");
while ((de = readdir(dir))) {
- errno = 0;
- stat(de->d_name, &st);
- if ((errno != ENOENT) && (errno != EACCES)) {
- pid = (pid_t) atoi((char *) basename((char *)
de->d_name));
- if (find_name && pid) {
- char *str = get_proc_name(pid);
- if (!str)
- continue;
- if (strcmp(str, find_name) != 0)
- pid = 0;
- }
- if (((ppid > 0) && (pid != ppid)) || !pid)
- continue;
+ /* Check the name first if it's an int as it's faster. */
+ pid = atoi(de->d_name);
+ if (pid == 0)
+ continue;
- wx = get_proc_maps(pid);
+ /* Get an open handle so the kernel won't reap on us later. */
+ pfd = open(de->d_name, O_RDONLY|O_CLOEXEC|O_PATH|O_DIRECTORY);
+ if (pfd == -1)
+ continue;
- if (noexec != writeexec) {
- if ((wx == 1) && (writeexec != wx))
- goto next_pid;
+ if (find_name && pid) {
+ char *str = get_proc_name(pfd);
+ if (!str)
+ goto next_pid;
+ if (strcmp(str, find_name) != 0)
+ pid = 0;
+ }
+ if (ppid > 0 && pid != ppid)
+ goto next_pid;
- if ((wx == 0) && writeexec)
- goto next_pid;
- }
+ wx = get_proc_maps(pfd);
- pwd = get_proc_passwd(pid);
- pax = get_proc_status(pid, "PAX");
- type = get_proc_type(pid);
- name = get_proc_name(pid);
- attr = (have_attr ? get_pid_attr(pid) : NULL);
- addr = (have_addr ? get_pid_addr(pid) : NULL);
-
- if (pwd) {
- if (show_uid != (uid_t)-1)
- if (pwd->pw_uid != show_uid)
- continue;
-
- if (show_gid != (gid_t)-1)
- if (pwd->pw_gid != show_gid)
- continue;
- }
+ if (noexec != writeexec) {
+ if (wx == 1 && writeexec != wx)
+ goto next_pid;
- /* this is a non-POSIX function */
- caps = NULL;
- WRAP_SYSCAP(capgetp(pid, cap_d));
- WRAP_SYSCAP(caps = cap_to_text(cap_d, &length));
-
- if (pwd && strlen(pwd->pw_name) >= 8)
- pwd->pw_name[8] = 0;
-
- if (show_all || type) {
- printf("%-8s %-6d %-6s %-4s %-10s %-16s %-4s %s
%s %s\n",
- pwd ? pwd->pw_name : "--------",
- pid,
- pax ? pax : "---",
- (wx == 1) ? "w|x" : (wx == -1) ? "---" :
"w^x",
- type ? type : "-------",
- name ? name : "-----",
- caps ? caps : " = ",
- attr ? attr : "",
- addr ? addr : "",
- show_phdr ? get_proc_phdr(pid) : "");
- if (verbose && wx)
- print_executable_mappings(pid);
- }
+ if (wx == 0 && writeexec)
+ goto next_pid;
+ }
- WRAP_SYSCAP(if (caps) cap_free(caps));
+ pwd = get_proc_passwd(pfd);
+ pax = get_proc_status(pfd, "PAX");
+ type = get_proc_type(pfd);
+ name = get_proc_name(pfd);
+ attr = (have_attr ? get_pid_attr(pfd) : NULL);
+ addr = (have_addr ? get_pid_addr(pfd) : NULL);
- next_pid:
- continue;
+ if (pwd) {
+ if (show_uid != (uid_t)-1)
+ if (pwd->pw_uid != show_uid)
+ goto next_pid;
+
+ if (show_gid != (gid_t)-1)
+ if (pwd->pw_gid != show_gid)
+ goto next_pid;
+ }
+
+ /* this is a non-POSIX function */
+ caps = NULL;
+ WRAP_SYSCAP(capgetp(pfd, cap_d));
+ WRAP_SYSCAP(caps = cap_to_text(cap_d, &length));
+
+ if (pwd && strlen(pwd->pw_name) >= 8)
+ pwd->pw_name[8] = 0;
+
+ if (show_all || type) {
+ printf("%-8s %-6d %-6s %-4s %-10s %-16s %-4s %s %s
%s\n",
+ pwd ? pwd->pw_name : "--------",
+ pid,
+ pax ? pax : "---",
+ (wx == 1) ? "w|x" : (wx == -1) ? "---" : "w^x",
+ type ? type : "-------",
+ name ? name : "-----",
+ caps ? caps : " = ",
+ attr ? attr : "",
+ addr ? addr : "",
+ show_phdr ? get_proc_phdr(pfd) : "");
+ if (verbose && wx)
+ print_executable_mappings(pfd);
}
+
+ WRAP_SYSCAP(if (caps) cap_free(caps));
+
+ next_pid:
+ close(pfd);
}
closedir(dir);
}
