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-rw-r--r--library/devname.c364
1 files changed, 364 insertions, 0 deletions
diff --git a/library/devname.c b/library/devname.c
new file mode 100644
index 0000000..6a23653
--- /dev/null
+++ b/library/devname.c
@@ -0,0 +1,364 @@
+/*
+ * devname - device name functions
+ *
+ * Copyright © 2011-2023 Jim Warner <james.warner@comcast.net>
+ * Copyright © 2017-2023 Craig Small <csmall@dropbear.xyz>
+ * Copyright © 1998-2009 Albert Cahalan
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "misc.h"
+#include "devname.h"
+
+// This is the buffer size for a tty name. Any path is legal,
+// which makes PAGE_SIZE appropriate (see kernel source), but
+// that is only 99% portable and utmp only holds 32 anyway.
+// We need at least 20 for guess_name().
+#define TTY_NAME_SIZE 128
+
+/* Who uses what:
+ *
+ * dev_to_tty top, ps
+ */
+
+#ifdef MAJOR_IN_MKDEV
+#include <sys/mkdev.h>
+#elif defined MAJOR_IN_SYSMACROS
+#include <sys/sysmacros.h>
+#else
+#define major(d) ( ((unsigned)(d)>>8u) & 0xfffu )
+#define minor(d) ( ((unsigned)(d)&0xffu) | (((unsigned)(d)&0xfff00000u)>>12u) )
+#endif
+
+typedef struct tty_map_node {
+ struct tty_map_node *next;
+ unsigned short devfs_type; // bool
+ unsigned short major_number;
+ unsigned minor_first;
+ unsigned minor_last;
+ char name[16];
+} tty_map_node;
+
+static __thread tty_map_node *tty_map = NULL;
+
+/* Load /proc/tty/drivers for device name mapping use. */
+static void load_drivers(void){
+ char buf[10000];
+ char *p;
+ int fd;
+ int bytes;
+ fd = open("/proc/tty/drivers",O_RDONLY);
+ if(fd == -1) goto fail;
+ bytes = read(fd, buf, sizeof(buf) - 1);
+ if(bytes == -1) goto fail;
+ buf[bytes] = '\0';
+ p = buf;
+ while(( p = strstr(p, " /dev/") )){ // " /dev/" is the second column
+ tty_map_node *tmn;
+ size_t len;
+ char *end;
+ p += 6;
+ end = strchr(p, ' ');
+ if(!end) continue;
+ len = end - p;
+ if (!(tmn = calloc(1, sizeof(tty_map_node))))
+ goto fail;
+ tmn->next = tty_map;
+ tty_map = tmn;
+ /* if we have a devfs type name such as /dev/tts/%d then strip the %d but
+ keep a flag. */
+ if(len >= 3 && !strncmp(end - 2, "%d", 2)){
+ len -= 2;
+ tmn->devfs_type = 1;
+ }
+ if(len >= sizeof tmn->name)
+ len = sizeof tmn->name - 1; // mangle it to avoid overflow
+ memcpy(tmn->name, p, len);
+ p = end; /* set p to point past the %d as well if there is one */
+ while(*p == ' ') p++;
+ tmn->major_number = atoi(p);
+ p += strspn(p, "0123456789");
+ while(*p == ' ') p++;
+ switch(sscanf(p, "%u-%u", &tmn->minor_first, &tmn->minor_last)){
+ default:
+ /* Can't finish parsing this line so we remove it from the list */
+ tty_map = tty_map->next;
+ free(tmn);
+ break;
+ case 1:
+ tmn->minor_last = tmn->minor_first;
+ break;
+ case 2:
+ break;
+ }
+ }
+fail:
+ if(fd != -1) close(fd);
+ if(!tty_map) tty_map = (tty_map_node *)-1;
+}
+
+/* Try to guess the device name from /proc/tty/drivers info. */
+static int driver_name(char *restrict const buf, unsigned maj, unsigned min){
+ struct stat sbuf;
+ tty_map_node *tmn;
+ if(!tty_map) load_drivers();
+ if(tty_map == (tty_map_node *)-1) return 0;
+ tmn = tty_map;
+ for(;;){
+ if(!tmn) return 0;
+ if(tmn->major_number == maj && tmn->minor_first <= min && tmn->minor_last >= min) break;
+ tmn = tmn->next;
+ }
+ sprintf(buf, "/dev/%s%d", tmn->name, min); /* like "/dev/ttyZZ255" */
+ if(stat(buf, &sbuf) < 0){
+ sprintf(buf, "/dev/%s/%d", tmn->name, min); /* like "/dev/pts/255" */
+ if(stat(buf, &sbuf) < 0){
+ if(tmn->devfs_type) return 0;
+ sprintf(buf, "/dev/%s", tmn->name); /* like "/dev/ttyZZ255" */
+ if(stat(buf, &sbuf) < 0) return 0;
+ }
+ }
+ if(min != minor(sbuf.st_rdev)) return 0;
+ if(maj != major(sbuf.st_rdev)) return 0;
+ return 1;
+}
+
+// major 204 is a mess -- "Low-density serial ports"
+static const char low_density_names[][6] = {
+"LU0", "LU1", "LU2", "LU3",
+"FB0",
+"SA0", "SA1", "SA2",
+"SC0", "SC1", "SC2", "SC3",
+"FW0", "FW1", "FW2", "FW3",
+"AM0", "AM1", "AM2", "AM3", "AM4", "AM5", "AM6", "AM7",
+"AM8", "AM9", "AM10", "AM11", "AM12", "AM13", "AM14", "AM15",
+"DB0", "DB1", "DB2", "DB3", "DB4", "DB5", "DB6", "DB7",
+"SG0",
+"SMX0", "SMX1", "SMX2",
+"MM0", "MM1",
+"CPM0", "CPM1", "CPM2", "CPM3", /* "CPM4", "CPM5", */ // bad allocation?
+"IOC0", "IOC1", "IOC2", "IOC3", "IOC4", "IOC5", "IOC6", "IOC7",
+"IOC8", "IOC9", "IOC10", "IOC11", "IOC12", "IOC13", "IOC14", "IOC15",
+"IOC16", "IOC17", "IOC18", "IOC19", "IOC20", "IOC21", "IOC22", "IOC23",
+"IOC24", "IOC25", "IOC26", "IOC27", "IOC28", "IOC29", "IOC30", "IOC31",
+"VR0", "VR1",
+"IOC84", "IOC85", "IOC86", "IOC87", "IOC88", "IOC89", "IOC90", "IOC91",
+"IOC92", "IOC93", "IOC94", "IOC95", "IOC96", "IOC97", "IOC98", "IOC99",
+"IOC100", "IOC101", "IOC102", "IOC103", "IOC104", "IOC105", "IOC106", "IOC107",
+"IOC108", "IOC109", "IOC110", "IOC111", "IOC112", "IOC113", "IOC114", "IOC115",
+"SIOC0", "SIOC1", "SIOC2", "SIOC3", "SIOC4", "SIOC5", "SIOC6", "SIOC7",
+"SIOC8", "SIOC9", "SIOC10", "SIOC11", "SIOC12", "SIOC13", "SIOC14", "SIOC15",
+"SIOC16", "SIOC17", "SIOC18", "SIOC19", "SIOC20", "SIOC21", "SIOC22", "SIOC23",
+"SIOC24", "SIOC25", "SIOC26", "SIOC27", "SIOC28", "SIOC29", "SIOC30", "SIOC31",
+"PSC0", "PSC1", "PSC2", "PSC3", "PSC4", "PSC5",
+"AT0", "AT1", "AT2", "AT3", "AT4", "AT5", "AT6", "AT7",
+"AT8", "AT9", "AT10", "AT11", "AT12", "AT13", "AT14", "AT15",
+"NX0", "NX1", "NX2", "NX3", "NX4", "NX5", "NX6", "NX7",
+"NX8", "NX9", "NX10", "NX11", "NX12", "NX13", "NX14", "NX15",
+"J0", // minor is 186
+"UL0","UL1","UL2","UL3",
+"xvc0", // FAIL -- "/dev/xvc0" lacks "tty" prefix
+"PZ0","PZ1","PZ2","PZ3",
+"TX0","TX1","TX2","TX3","TX4","TX5","TX6","TX7",
+"SC0","SC1","SC2","SC3",
+"MAX0","MAX1","MAX2","MAX3",
+};
+
+#if 0
+// test code
+#include <stdio.h>
+#define AS(x) (sizeof(x)/sizeof((x)[0]))
+int main(int argc, char *argv[]){
+ int i = 0;
+ while(i<AS(low_density_names)){
+ printf("%3d = /dev/tty%.*s\n",i,sizeof low_density_names[i],low_density_names[i]);
+ i++;
+ }
+ return 0;
+}
+#endif
+
+/* Try to guess the device name (useful until /proc/PID/tty is added) */
+static int guess_name(char *restrict const buf, unsigned maj, unsigned min){
+ struct stat sbuf;
+#ifndef __CYGWIN__
+ int t0, t1;
+#endif
+ unsigned tmpmin = min;
+
+ switch(maj){
+ case 3: /* /dev/[pt]ty[p-za-o][0-9a-z] is 936 */
+ if(tmpmin > 255) return 0; // should never happen; array index protection
+#ifdef __CYGWIN__
+ sprintf(buf, "cons%d", tmpmin);
+ /* Skip stat call. The reason is that cons devices are local to
+ * the processes running in that console. Calling stat from another
+ * console or pty will return -1. */
+ return 1;
+#else
+ t0 = "pqrstuvwxyzabcde"[tmpmin>>4];
+ t1 = "0123456789abcdef"[tmpmin&0x0f];
+ sprintf(buf, "/dev/tty%c%c", t0, t1);
+#endif
+ break;
+ case 4:
+ if(min<64){
+ sprintf(buf, "/dev/tty%d", min);
+ break;
+ }
+ sprintf(buf, "/dev/ttyS%d", min-64);
+ break;
+ case 11: sprintf(buf, "/dev/ttyB%d", min); break;
+ case 17: sprintf(buf, "/dev/ttyH%d", min); break;
+ case 19: sprintf(buf, "/dev/ttyC%d", min); break;
+ case 22: sprintf(buf, "/dev/ttyD%d", min); break; /* devices.txt */
+ case 23: sprintf(buf, "/dev/ttyD%d", min); break; /* driver code */
+ case 24: sprintf(buf, "/dev/ttyE%d", min); break;
+ case 32: sprintf(buf, "/dev/ttyX%d", min); break;
+ case 43: sprintf(buf, "/dev/ttyI%d", min); break;
+ case 46: sprintf(buf, "/dev/ttyR%d", min); break;
+ case 48: sprintf(buf, "/dev/ttyL%d", min); break;
+ case 57: sprintf(buf, "/dev/ttyP%d", min); break;
+ case 71: sprintf(buf, "/dev/ttyF%d", min); break;
+ case 75: sprintf(buf, "/dev/ttyW%d", min); break;
+ case 78: sprintf(buf, "/dev/ttyM%d", min); break; /* conflict */
+ case 105: sprintf(buf, "/dev/ttyV%d", min); break;
+ case 112: sprintf(buf, "/dev/ttyM%d", min); break; /* conflict */
+#ifdef __CYGWIN__
+ case 136: sprintf(buf, "/dev/pty%d", min); break;
+#else
+ /* 136 ... 143 are /dev/pts/0, /dev/pts/1, /dev/pts/2 ... */
+ case 136 ... 143: sprintf(buf, "/dev/pts/%d", min+(maj-136)*256); break;
+#endif
+ case 148: sprintf(buf, "/dev/ttyT%d", min); break;
+ case 154: sprintf(buf, "/dev/ttySR%d", min); break;
+ case 156: sprintf(buf, "/dev/ttySR%d", min+256); break;
+ case 164: sprintf(buf, "/dev/ttyCH%d", min); break;
+ case 166: sprintf(buf, "/dev/ttyACM%d", min); break; /* bummer, 9-char */
+ case 172: sprintf(buf, "/dev/ttyMX%d", min); break;
+ case 174: sprintf(buf, "/dev/ttySI%d", min); break;
+ case 188: sprintf(buf, "/dev/ttyUSB%d", min); break; /* bummer, 9-char */
+ case 204:
+ if(min >= sizeof low_density_names / sizeof low_density_names[0]) return 0;
+ memcpy(buf,"/dev/tty",8);
+ memcpy(buf+8, low_density_names[min], sizeof low_density_names[0]);
+ buf[8 + sizeof low_density_names[0]] = '\0';
+// snprintf(buf, 9 + sizeof low_density_names[0], "/dev/tty%.*s", sizeof low_density_names[0], low_density_names[min]);
+ break;
+ case 208: sprintf(buf, "/dev/ttyU%d", min); break;
+ case 216: sprintf(buf, "/dev/ttyUB%d", min); break; // "/dev/rfcomm%d" now?
+ case 224: sprintf(buf, "/dev/ttyY%d", min); break;
+ case 227: sprintf(buf, "/dev/3270/tty%d", min); break; /* bummer, HUGE */
+ case 229: sprintf(buf, "/dev/iseries/vtty%d", min); break; /* bummer, HUGE */
+ case 256: sprintf(buf, "/dev/ttyEQ%d", min); break;
+ default: return 0;
+ }
+ if(stat(buf, &sbuf) < 0) return 0;
+ if(min != minor(sbuf.st_rdev)) return 0;
+ if(maj != major(sbuf.st_rdev)) return 0;
+ return 1;
+}
+
+/* Linux 2.2 can give us filenames that might be correct.
+ * Useful names could be in /proc/PID/fd/2 (stderr, seldom redirected)
+ * and in /proc/PID/fd/255 (used by bash to remember the tty).
+ */
+static int link_name(char *restrict const buf, unsigned maj, unsigned min, int pid, const char *restrict name){
+ struct stat sbuf;
+ char path[32];
+ ssize_t count;
+ const int len = snprintf(path, sizeof path, "/proc/%d/%s", pid, name); /* often permission denied */
+ if(len <= 0 || (size_t)len >= sizeof path) return 0;
+ count = readlink(path,buf,TTY_NAME_SIZE-1);
+ if(count <= 0 || count >= TTY_NAME_SIZE-1) return 0;
+ buf[count] = '\0';
+ if(stat(buf, &sbuf) < 0) return 0;
+ if(min != minor(sbuf.st_rdev)) return 0;
+ if(maj != major(sbuf.st_rdev)) return 0;
+ return 1;
+}
+
+#ifdef USE_PROC_CTTY
+/* Cygwin keeps the name to the controlling tty in a virtual file called
+ /proc/PID/ctty, including a trailing LF (sigh). */
+static int ctty_name(char *restrict const buf, int pid) {
+ char path[32];
+ FILE *fp;
+ char *lf;
+ sprintf (path, "/proc/%d/ctty", pid); /* often permission denied */
+ fp = fopen (path, "r");
+ if (!fp)
+ return 0;
+ if (!fgets (buf,TTY_NAME_SIZE,fp))
+ {
+ fclose (fp);
+ return 0;
+ }
+ fclose (fp);
+ lf = strchr (buf, '\n');
+ if (lf)
+ *lf = (lf == buf ? '?' : '\0');
+ return 1;
+}
+#endif
+
+/* number --> name */
+unsigned dev_to_tty(char *restrict ret, unsigned chop, dev_t dev_t_dev, int pid, unsigned int flags) {
+ static __thread char buf[TTY_NAME_SIZE];
+ char *restrict tmp = buf;
+ unsigned dev = dev_t_dev;
+ unsigned i = 0;
+ int c;
+#ifdef USE_PROC_CTTY
+ if( ctty_name(tmp, pid )) goto abbrev;
+#endif
+ if(dev == 0u) goto no_tty;
+ if(driver_name(tmp, major(dev), minor(dev) )) goto abbrev;
+ if( link_name(tmp, major(dev), minor(dev), pid, "fd/2" )) goto abbrev;
+ if( guess_name(tmp, major(dev), minor(dev) )) goto abbrev;
+ if( link_name(tmp, major(dev), minor(dev), pid, "fd/255")) goto abbrev;
+ // fall through if unable to find a device file
+no_tty:
+ strcpy(ret, chop >= 1 ? "?" : "");
+ return 1;
+abbrev:
+ if((flags&ABBREV_DEV) && !strncmp(tmp,"/dev/",5) && tmp[5]) tmp += 5;
+ if((flags&ABBREV_TTY) && !strncmp(tmp,"tty", 3) && tmp[3]) tmp += 3;
+ if((flags&ABBREV_PTS) && !strncmp(tmp,"pts/", 4) && tmp[4]) tmp += 4;
+ /* gotta check before we chop or we may chop someone else's memory */
+ if(chop + (unsigned long)(tmp-buf) < sizeof buf)
+ tmp[chop] = '\0';
+ /* replace non-ASCII characters with '?' and return the number of chars */
+ while(i < chop){
+ c = *tmp;
+ tmp++;
+ if(!c) break;
+ i++;
+ if(c<=' ') c = '?';
+ if(c>126) c = '?';
+ *ret = c;
+ ret++;
+ }
+ *ret = '\0';
+ return i;
+}
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