diff options
Diffstat (limited to 'util.c')
| -rw-r--r-- | util.c | 87 |
1 files changed, 78 insertions, 9 deletions
@@ -25,6 +25,7 @@ #include <errno.h> #include <stdbool.h> #include <linux/errqueue.h> +#include <linux/in6.h> #include <getopt.h> #include "linux_dep.h" @@ -35,10 +36,14 @@ #include "log.h" #include "pcap.h" #include "epoll_ctl.h" +#include "pasta.h" #ifdef HAS_GETRANDOM #include <sys/random.h> #endif +/* Zero-filled buffer to pad 802.3 frames, up to 60 (ETH_ZLEN) bytes */ +uint8_t eth_pad[ETH_ZLEN] = { 0 }; + /** * sock_l4_() - Create and bind socket to socket address * @c: Execution context @@ -552,7 +557,7 @@ void pidfile_write(int fd, pid_t pid) if (write(fd, pid_buf, n) < 0) { perror("PID file write"); - _exit(EXIT_FAILURE); + passt_exit(EXIT_FAILURE); } close(fd); @@ -589,12 +594,12 @@ int __daemon(int pidfile_fd, int devnull_fd) if (pid == -1) { perror("fork"); - _exit(EXIT_FAILURE); + passt_exit(EXIT_FAILURE); } if (pid) { pidfile_write(pidfile_fd, pid); - _exit(EXIT_SUCCESS); + passt_exit(EXIT_SUCCESS); } if (setsid() < 0 || @@ -602,7 +607,7 @@ int __daemon(int pidfile_fd, int devnull_fd) dup2(devnull_fd, STDOUT_FILENO) < 0 || dup2(devnull_fd, STDERR_FILENO) < 0 || close(devnull_fd)) - _exit(EXIT_FAILURE); + passt_exit(EXIT_FAILURE); return 0; } @@ -611,6 +616,9 @@ int __daemon(int pidfile_fd, int devnull_fd) * fls() - Find last (most significant) bit set in word * @x: Word * + * Note: unlike ffs() and other implementations of fls(), notably the one from + * the Linux kernel, the starting position is 0 and not 1, that is, fls(1) = 0. + * * Return: position of most significant bit set, starting from 0, -1 if none */ int fls(unsigned long x) @@ -627,6 +635,17 @@ int fls(unsigned long x) } /** + * ilog2() - Integral part (floor) of binary logarithm (logarithm to the base 2) + * @x: Argument + * + * Return: integral part of binary logarithm of @x, -1 if undefined (if @x is 0) + */ +int ilog2(unsigned long x) +{ + return fls(x); +} + +/** * write_file() - Replace contents of file with a string * @path: File to write * @buf: String to write @@ -697,7 +716,7 @@ static ssize_t read_file(const char *path, char *buf, size_t buf_size) close(fd); - if (total_read == buf_size) { + if (total_read >= buf_size) { buf[buf_size - 1] = '\0'; return -ENOBUFS; } @@ -1141,7 +1160,7 @@ void raw_random(void *buf, size_t buflen) ret = getrandom((char *)buf + random_read, buflen - random_read, GRND_RANDOM); #else - ret = read(dev_random, (char *)buf + random_read, + ret = read(fd, (char *)buf + random_read, buflen - random_read); #endif @@ -1158,7 +1177,7 @@ void raw_random(void *buf, size_t buflen) } #ifndef HAS_GETRANDOM - close(dev_random); + close(fd); #endif if (random_read < buflen) @@ -1208,15 +1227,65 @@ void abort_with_msg(const char *fmt, ...) } /** - * fsync_pcap_and_log() - Flush pcap and log files as needed + * passt_exit() - Perform vital cleanup and exit + * + * We don't use exit(3) because on some C library versions it can do unexpected + * things that hit our seccomp profile (e.g. futex() calls). This is a bespoke + * wrapper around _exit(2) performing just the cleanup that we need. * * #syscalls fsync */ -void fsync_pcap_and_log(void) +void passt_exit(int status) { + /* Make sure we don't leave the pcap file truncated */ if (pcap_fd != -1 && fsync(pcap_fd)) warn_perror("Failed to flush pcap file, it might be truncated"); + /* Make sure we don't leave an incomplete log */ if (log_file != -1) (void)fsync(log_file); + + /* Make sure we don't leave any messages incomplete */ + (void)fflush(stderr); + (void)fflush(stdout); + + _exit(status); +} + +/** + * clamped_scale() - Scale @x from 100% to f% depending on @y's value + * @x: Value to scale + * @y: Value determining scaling + * @lo: Lower bound for @y (start of y-axis slope) + * @hi: Upper bound for @y (end of y-axis slope) + * @f: Scaling factor, percent (might be less or more than 100) + * + * Return: @x scaled by @f * linear interpolation of @y between @lo and @hi + * + * In pictures: + * + * f % -> ,---- * If @y < lo (for example, @y is y0), return @x + * /| | + * / | | * If @lo < @y < @hi (for example, @y is y1), + * / | | return @x scaled by a factor linearly + * (100 + f) / 2 % ->/ | | interpolated between 100% and f% depending on + * /| | | @y's position between @lo (100%) and @hi (f%) + * / | | | + * / | | | * If @y > @hi (for example, @y is y2), return + * 100 % -> -----' | | | @x * @f / 100 + * | | | | | + * y0 lo y1 hi y2 Example: @f = 150, @lo = 10, @hi = 20, @y = 15, + * @x = 1000 + * -> interpolated factor is 125% + * -> return 1250 + */ +long clamped_scale(long x, long y, long lo, long hi, long f) +{ + if (y < lo) + return x; + + if (y > hi) + return x * f / 100; + + return x - (x * (y - lo) / (hi - lo)) * (100 - f) / 100; } |