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lsfd-cmd/cdev.c
829 строк
19 KB
Masatake YAMATO
lsfd: fill SOCK.NETNS column for tuntap
24 фев 2026, 21:23
24 фев 2026, 21:23
6fbf7a6
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/* * lsfd-cdev.c - handle associations opening character devices * * Copyright (C) 2021 Red Hat, Inc. All rights reserved. * Written by Masatake YAMATO <yamato@redhat.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it would be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "lsfd.h" #include "pidfd-utils.h" #include <sys/ioctl.h> /* ioctl */ #include <linux/if_tun.h> /* TUNGETDEVNETNS */ static struct list_head miscdevs; static struct list_head ttydrvs; struct miscdev { struct list_head miscdevs; unsigned long minor; char *name; }; struct ttydrv { struct list_head ttydrvs; unsigned long major; unsigned long minor_start, minor_end; char *name; unsigned int is_ptmx: 1; unsigned int is_pts: 1; }; struct cdev { struct file file; const char *devdrv; const struct cdev_ops *cdev_ops; void *cdev_data; }; struct cdev_ops { const struct cdev_ops *parent; bool (*probe)(struct cdev *); char * (*get_name)(struct cdev *); bool (*fill_column)(struct proc *, struct cdev *, struct libscols_line *, int, size_t, char **); void (*init)(const struct cdev *); void (*free)(const struct cdev *); bool (*needs_target_fd)(struct cdev *); void (*inspect_target_fd)(struct cdev *, int); void (*attach_xinfo)(struct cdev *); int (*handle_fdinfo)(struct cdev *, const char *, const char *); const struct ipc_class * (*get_ipc_class)(struct cdev *); }; static bool cdev_fill_column(struct proc *proc __attribute__((__unused__)), struct file *file, struct libscols_line *ln, int column_id, size_t column_index) { struct cdev *cdev = (struct cdev *)file; const struct cdev_ops *ops = cdev->cdev_ops; char *str = NULL; switch(column_id) { case COL_NAME: if (cdev->cdev_ops->get_name) { str = cdev->cdev_ops->get_name(cdev); if (str) break; } return false; case COL_TYPE: if (scols_line_set_data(ln, column_index, "CHR")) err(EXIT_FAILURE, _("failed to add output data")); return true; case COL_DEVTYPE: if (scols_line_set_data(ln, column_index, "char")) err(EXIT_FAILURE, _("failed to add output data")); return true; case COL_CHRDRV: if (cdev->devdrv) str = xstrdup(cdev->devdrv); else xasprintf(&str, "%u", major(file->stat.st_rdev)); break; default: while (ops) { if (ops->fill_column && ops->fill_column(proc, cdev, ln, column_id, column_index, &str)) goto out; ops = ops->parent; } return false; } out: if (!str) err(EXIT_FAILURE, _("failed to add output data")); if (scols_line_refer_data(ln, column_index, str)) err(EXIT_FAILURE, _("failed to add output data")); return true; } static struct miscdev *new_miscdev(unsigned long minor, const char *name) { struct miscdev *miscdev = xcalloc(1, sizeof(*miscdev)); INIT_LIST_HEAD(&miscdev->miscdevs); miscdev->minor = minor; miscdev->name = xstrdup(name); return miscdev; } static void free_miscdev(struct miscdev *miscdev) { free(miscdev->name); free(miscdev); } static void read_misc(struct list_head *miscdevs_list, FILE *misc_fp) { unsigned long minor; char line[256]; char name[sizeof(line)]; while (fgets(line, sizeof(line), misc_fp)) { struct miscdev *miscdev; if (sscanf(line, "%lu %s", &minor, name) != 2) continue; miscdev = new_miscdev(minor, name); list_add_tail(&miscdev->miscdevs, miscdevs_list); } } #define TTY_DRIVERS_LINE_LEN0 1023 #define TTY_DRIVERS_LINE_LEN (TTY_DRIVERS_LINE_LEN0 + 1) static struct ttydrv *new_ttydrv(unsigned int major, unsigned int minor_start, unsigned int minor_end, const char *name) { struct ttydrv *ttydrv = xmalloc(sizeof(*ttydrv)); INIT_LIST_HEAD(&ttydrv->ttydrvs); ttydrv->major = major; ttydrv->minor_start = minor_start; ttydrv->minor_end = minor_end; ttydrv->name = xstrdup(name); ttydrv->is_ptmx = 0; if (strcmp(name, "ptmx") == 0) ttydrv->is_ptmx = 1; ttydrv->is_pts = 0; if (strcmp(name, "pts") == 0) ttydrv->is_pts = 1; return ttydrv; } static void free_ttydrv(struct ttydrv *ttydrv) { free(ttydrv->name); free(ttydrv); } static bool is_pty(const struct ttydrv *ttydrv) { return ttydrv->is_ptmx || ttydrv->is_pts; } static struct ttydrv *read_ttydrv(const char *line) { const char *p; char name[TTY_DRIVERS_LINE_LEN]; unsigned long major; unsigned long minor_range[2]; p = strchr(line, ' '); if (p == NULL) return NULL; p = strstr(p, "/dev/"); if (p == NULL) return NULL; p += (sizeof("/dev/") - 1); /* Ignore the last null byte. */ if (sscanf(p, "%" stringify_value(TTY_DRIVERS_LINE_LEN0) "[^ ]", name) != 1) return NULL; p += strlen(name); if (sscanf(p, " %lu %lu-%lu ", &major, minor_range, minor_range + 1) != 3) { if (sscanf(p, " %lu %lu ", &major, minor_range) == 2) minor_range[1] = minor_range[0]; else return NULL; } return new_ttydrv(major, minor_range[0], minor_range[1], name); } static void read_tty_drivers(struct list_head *ttydrvs_list, FILE *ttydrvs_fp) { char line[TTY_DRIVERS_LINE_LEN]; while (fgets(line, sizeof(line), ttydrvs_fp)) { struct ttydrv *ttydrv = read_ttydrv(line); if (ttydrv) list_add_tail(&ttydrv->ttydrvs, ttydrvs_list); } } static void cdev_class_initialize(void) { FILE *misc_fp; FILE *ttydrvs_fp; INIT_LIST_HEAD(&miscdevs); INIT_LIST_HEAD(&ttydrvs); misc_fp = fopen("/proc/misc", "r"); if (misc_fp) { read_misc(&miscdevs, misc_fp); fclose(misc_fp); } ttydrvs_fp = fopen("/proc/tty/drivers", "r"); if (ttydrvs_fp) { read_tty_drivers(&ttydrvs, ttydrvs_fp); fclose(ttydrvs_fp); } } static void cdev_class_finalize(void) { list_free(&miscdevs, struct miscdev, miscdevs, free_miscdev); list_free(&ttydrvs, struct ttydrv, ttydrvs, free_ttydrv); } const char *get_miscdev(unsigned long minor) { struct list_head *c; list_for_each(c, &miscdevs) { struct miscdev *miscdev = list_entry(c, struct miscdev, miscdevs); if (miscdev->minor == minor) return miscdev->name; } return NULL; } static const struct ttydrv *get_ttydrv(unsigned long major, unsigned long minor) { struct list_head *c; list_for_each(c, &ttydrvs) { struct ttydrv *ttydrv = list_entry(c, struct ttydrv, ttydrvs); if (ttydrv->major == major && ttydrv->minor_start <= minor && minor <= ttydrv->minor_end) return ttydrv; } return NULL; } /* * generic (fallback implementation) */ static bool cdev_generic_probe(struct cdev *cdev __attribute__((__unused__))) { return true; } static bool cdev_generic_fill_column(struct proc *proc __attribute__((__unused__)), struct cdev *cdev, struct libscols_line *ln __attribute__((__unused__)), int column_id, size_t column_index __attribute__((__unused__)), char **str) { struct file *file = &cdev->file; switch(column_id) { case COL_SOURCE: if (cdev->devdrv) { xasprintf(str, "%s:%u", cdev->devdrv, minor(file->stat.st_rdev)); return true; } FALLTHROUGH; case COL_MAJMIN: xasprintf(str, "%u:%u", major(file->stat.st_rdev), minor(file->stat.st_rdev)); return true; default: return false; } } static struct cdev_ops cdev_generic_ops = { .probe = cdev_generic_probe, .fill_column = cdev_generic_fill_column, }; /* * misc device driver */ static bool cdev_misc_probe(struct cdev *cdev) { return cdev->devdrv && strcmp(cdev->devdrv, "misc") == 0; } static bool cdev_misc_fill_column(struct proc *proc __attribute__((__unused__)), struct cdev *cdev, struct libscols_line *ln __attribute__((__unused__)), int column_id, size_t column_index __attribute__((__unused__)), char **str) { struct file *file = &cdev->file; const char *miscdev; switch(column_id) { case COL_MISCDEV: miscdev = get_miscdev(minor(file->stat.st_rdev)); if (miscdev) *str = xstrdup(miscdev); else xasprintf(str, "%u", minor(file->stat.st_rdev)); return true; case COL_SOURCE: miscdev = get_miscdev(minor(file->stat.st_rdev)); if (miscdev) xasprintf(str, "misc:%s", miscdev); else xasprintf(str, "misc:%u", minor(file->stat.st_rdev)); return true; } return false; } static struct cdev_ops cdev_misc_ops = { .parent = &cdev_generic_ops, .probe = cdev_misc_probe, .fill_column = cdev_misc_fill_column, }; /* * tun device driver */ struct tundata { const char *iff; ino_t devnetns; /* 0 implies no value given. */ ino_t socknetns; }; static bool cdev_tun_probe(struct cdev *cdev) { const char *miscdev; if ((!cdev->devdrv) || strcmp(cdev->devdrv, "misc")) return false; miscdev = get_miscdev(minor(cdev->file.stat.st_rdev)); if (miscdev && strcmp(miscdev, "tun") == 0) { struct tundata *tundata = xcalloc(1, sizeof *tundata); cdev->cdev_data = tundata; return true; } return false; } static void cdev_tun_free(const struct cdev *cdev) { if (cdev->cdev_data) { struct tundata *tundata = cdev->cdev_data; free((void *)tundata->iff); free(tundata); } } static char * cdev_tun_get_name(struct cdev *cdev) { char *str = NULL; struct tundata *tundata = cdev->cdev_data; if (tundata == NULL || tundata->iff == NULL) return NULL; xasprintf(&str, "iface=%s", tundata->iff); if (tundata->devnetns) xstrfappend(&str, " devnetns=%llu", (unsigned long long)tundata->devnetns); if (tundata->socknetns) xstrfappend(&str, " socknetns=%llu", (unsigned long long)tundata->socknetns); return str; } static bool cdev_tun_fill_column(struct proc *proc __attribute__((__unused__)), struct cdev *cdev, struct libscols_line *ln __attribute__((__unused__)), int column_id, size_t column_index __attribute__((__unused__)), char **str) { struct tundata *tundata = cdev->cdev_data; switch(column_id) { case COL_MISCDEV: *str = xstrdup("tun"); return true; case COL_SOURCE: *str = xstrdup("misc:tun"); return true; case COL_TUN_DEVNETNS: if (tundata && tundata->devnetns) { xasprintf(str, "%llu", (unsigned long long)tundata->devnetns); return true; } break; case COL_TUN_IFACE: if (tundata && tundata->iff) { *str = xstrdup(tundata->iff); return true; } break; case COL_SOCK_NETNS: if (tundata && tundata->socknetns) { xasprintf(str, "%llu", (unsigned long long)tundata->socknetns); return true; } break; } return false; } static int cdev_tun_handle_fdinfo(struct cdev *cdev, const char *key, const char *val) { struct tundata *tundata = cdev->cdev_data; if (strcmp(key, "iff") == 0 && tundata->iff == NULL) { tundata->iff = xstrdup(val); return 1; } return 0; } static bool cdev_tun_needs_target_fd(struct cdev *cdev) { struct tundata *tundata = cdev->cdev_data; return (tundata->iff != NULL); } static void cdev_tun_inspect_target_fd(struct cdev *cdev, int fd) { struct tundata *tundata = cdev->cdev_data; tundata->socknetns = get_netns_from_socket(fd); #ifdef TUNGETDEVNETNS int nsfd = ioctl(fd, TUNGETDEVNETNS); struct stat sb; if (nsfd < 0) return; if (fstat(nsfd, &sb) == 0) { tundata->devnetns = sb.st_ino; load_fdsk_xinfo(tundata->devnetns, nsfd); } close(nsfd); #endif /* TUNGETDEVNETNS */ } static struct cdev_ops cdev_tun_ops = { .parent = &cdev_misc_ops, .probe = cdev_tun_probe, .free = cdev_tun_free, .get_name = cdev_tun_get_name, .fill_column = cdev_tun_fill_column, .handle_fdinfo = cdev_tun_handle_fdinfo, .needs_target_fd = cdev_tun_needs_target_fd, .inspect_target_fd = cdev_tun_inspect_target_fd, }; /* * tty devices */ struct ttydata { struct cdev *cdev; const struct ttydrv *drv; #define NO_TTY_INDEX -1 int tty_index; /* used only in ptmx devices */ struct ipc_endpoint endpoint; }; static bool cdev_tty_probe(struct cdev *cdev) { const struct ttydrv *ttydrv = get_ttydrv(major(cdev->file.stat.st_rdev), minor(cdev->file.stat.st_rdev)); struct ttydata *data; if (!ttydrv) return false; data = xmalloc(sizeof(struct ttydata)); data->cdev = cdev; data->drv = ttydrv; data->tty_index = NO_TTY_INDEX; cdev->cdev_data = data; return true; } static void cdev_tty_free(const struct cdev *cdev) { if (cdev->cdev_data) free(cdev->cdev_data); } static char * cdev_tty_get_name(struct cdev *cdev) { struct ttydata *data = cdev->cdev_data; char *str = NULL; if (!data->drv->is_ptmx) return NULL; if (data->tty_index == NO_TTY_INDEX) str = xstrdup("tty-index="); else xasprintf(&str, "tty-index=%d", data->tty_index); return str; } static inline char *cdev_tty_xstrendpoint(struct file *file) { char *str = NULL; xasprintf(&str, "%d,%s,%d%c%c", file->proc->pid, file->proc->command, file->association, (file->mode & S_IRUSR)? 'r': '-', (file->mode & S_IWUSR)? 'w': '-'); return str; } static bool cdev_tty_fill_column(struct proc *proc __attribute__((__unused__)), struct cdev *cdev, struct libscols_line *ln __attribute__((__unused__)), int column_id, size_t column_index __attribute__((__unused__)), char **str) { struct file *file = &cdev->file; struct ttydata *data = cdev->cdev_data; switch(column_id) { case COL_SOURCE: if (data->drv->minor_start == data->drv->minor_end) *str = xstrdup(data->drv->name); else xasprintf(str, "%s:%u", data->drv->name, minor(file->stat.st_rdev)); return true; case COL_PTMX_TTY_INDEX: if (data->drv->is_ptmx) { xasprintf(str, "%d", data->tty_index); return true; } return false; case COL_ENDPOINTS: if (is_pty(data->drv)) { struct ttydata *this = data; struct list_head *e; foreach_endpoint(e, data->endpoint) { char *estr; struct ttydata *other = list_entry(e, struct ttydata, endpoint.endpoints); if (this == other) continue; if ((this->drv->is_ptmx && !other->drv->is_pts) || (this->drv->is_pts && !other->drv->is_ptmx)) continue; if (*str) xstrputc(str, '\n'); estr = cdev_tty_xstrendpoint(&other->cdev->file); xstrappend(str, estr); free(estr); } if (*str) return true; } return false; default: return false; } } static int cdev_tty_handle_fdinfo(struct cdev *cdev, const char *key, const char *val) { struct ttydata *data = cdev->cdev_data; if (!data->drv->is_ptmx) return 0; if (strcmp(key, "tty-index") == 0) { errno = 0; data->tty_index = (int)strtol(val, NULL, 10); if (errno) { data->tty_index = NO_TTY_INDEX; return 0; } return 1; } return 0; } struct cdev_pty_ipc { struct ipc ipc; int tty_index; }; static unsigned int cdev_pty_get_hash(struct file *file) { struct cdev *cdev = (struct cdev *)file; struct ttydata *data = cdev->cdev_data; return data->drv->is_ptmx? (unsigned int)data->tty_index: (unsigned int)minor(file->stat.st_rdev); } static bool cdev_pty_is_suitable_ipc(struct ipc *ipc, struct file *file) { struct cdev *cdev = (struct cdev *)file; struct ttydata *data = cdev->cdev_data; struct cdev_pty_ipc *cdev_pty_ipc = (struct cdev_pty_ipc *)ipc; return (data->drv->is_ptmx)? cdev_pty_ipc->tty_index == (int)data->tty_index: cdev_pty_ipc->tty_index == (int)minor(file->stat.st_rdev); } static const struct ipc_class *cdev_tty_get_ipc_class(struct cdev *cdev) { static const struct ipc_class cdev_pty_ipc_class = { .size = sizeof(struct cdev_pty_ipc), .get_hash = cdev_pty_get_hash, .is_suitable_ipc = cdev_pty_is_suitable_ipc, }; struct ttydata *data = cdev->cdev_data; if (is_pty(data->drv)) return &cdev_pty_ipc_class; return NULL; } static void cdev_tty_attach_xinfo(struct cdev *cdev) { struct ttydata *data = cdev->cdev_data; struct ipc *ipc; unsigned int hash; if (! is_pty(data->drv)) return; init_endpoint(&data->endpoint); ipc = get_ipc(&cdev->file); if (ipc) goto link; ipc = new_ipc(cdev_tty_get_ipc_class(cdev)); hash = cdev_pty_get_hash(&cdev->file); ((struct cdev_pty_ipc *)ipc)->tty_index = (int)hash; add_ipc(ipc, hash); link: add_endpoint(&data->endpoint, ipc); } static struct cdev_ops cdev_tty_ops = { .parent = &cdev_generic_ops, .probe = cdev_tty_probe, .free = cdev_tty_free, .get_name = cdev_tty_get_name, .fill_column = cdev_tty_fill_column, .attach_xinfo = cdev_tty_attach_xinfo, .handle_fdinfo = cdev_tty_handle_fdinfo, .get_ipc_class = cdev_tty_get_ipc_class, }; static const struct cdev_ops *const cdev_ops[] = { &cdev_tun_ops, &cdev_misc_ops, &cdev_tty_ops, &cdev_generic_ops /* This must be at the end. */ }; static const struct cdev_ops *cdev_probe(struct cdev *cdev) { const struct cdev_ops *r = NULL; for (size_t i = 0; i < ARRAY_SIZE(cdev_ops); i++) { if (cdev_ops[i]->probe(cdev)) { r = cdev_ops[i]; break; } } assert(r); return r; } static void init_cdev_content(struct file *file) { struct cdev *cdev = (struct cdev *)file; cdev->devdrv = get_chrdrv(major(file->stat.st_rdev)); cdev->cdev_data = NULL; cdev->cdev_ops = cdev_probe(cdev); if (cdev->cdev_ops->init) cdev->cdev_ops->init(cdev); } static void free_cdev_content(struct file *file) { struct cdev *cdev = (struct cdev *)file; if (cdev->cdev_ops->free) cdev->cdev_ops->free(cdev); } static void cdev_attach_xinfo(struct file *file) { struct cdev *cdev = (struct cdev *)file; if (cdev->cdev_ops->attach_xinfo) cdev->cdev_ops->attach_xinfo(cdev); } static int cdev_handle_fdinfo(struct file *file, const char *key, const char *value) { struct cdev *cdev = (struct cdev *)file; if (cdev->cdev_ops->handle_fdinfo) return cdev->cdev_ops->handle_fdinfo(cdev, key, value); return 0; /* Should be handled in parents */ } static const struct ipc_class *cdev_get_ipc_class(struct file *file) { struct cdev *cdev = (struct cdev *)file; if (cdev->cdev_ops->get_ipc_class) return cdev->cdev_ops->get_ipc_class(cdev); return NULL; } static bool cdev_needs_target_fd(struct file *file) { struct cdev *cdev = (struct cdev *)file; if (cdev->cdev_ops->needs_target_fd) return cdev->cdev_ops->needs_target_fd(cdev); return false; } static void cdev_inspect_target_fd(struct file *file, int fd) { struct cdev *cdev = (struct cdev *)file; if (cdev->cdev_ops->inspect_target_fd) cdev->cdev_ops->inspect_target_fd(cdev, fd); } const struct file_class cdev_class = { .super = &file_class, .size = sizeof(struct cdev), .initialize_class = cdev_class_initialize, .finalize_class = cdev_class_finalize, .fill_column = cdev_fill_column, .initialize_content = init_cdev_content, .free_content = free_cdev_content, .attach_xinfo = cdev_attach_xinfo, .handle_fdinfo = cdev_handle_fdinfo, .get_ipc_class = cdev_get_ipc_class, .needs_target_fd = cdev_needs_target_fd, .inspect_target_fd = cdev_inspect_target_fd, };